# Calling All Sparky's (electrics) Need Help With Simple Schematics



## funkyyyy (10/7/11)

Okay heY everyone, I am in desperation for confirmation that these schematics will work. This seemed like the most suitable forum section to post this, apologies if it is not.

I am in year 12 doing my HSC, and for DT I have decided to construct a guitar cabinet in which ambient temperature can be controlled and monitored (preserves guitar in extremes of weather).

I have come up with my system, and will do my best to explain it to you below. Could you please tell me if it would work?













Okay as you can see I am running power from the wall, into the thermostat, and the thermostat is distributing power according to what temperature I set it at. I am using the ATX power supply as an "inverter" so I can cool the case with the 120mm fans which run on 12V instead of 220V. What do you guys think? Here is an image of the thermostat's inputs and outputs:








CHEERS


----------



## crozdog (10/7/11)

concept seems fine. AFAIK, the stc1000 will do just what you want.

Checkout this site for info on wiring it up. http://homebrewrecipes.kirschbaum.co.nz/di...-to-wire-it-up/

Be aware that the unit isn't "distributing power" it simply switches on the appropriate output which you have wired power to.

A couple of thoughts:
1. Instead of adding an ATX PSU for 12v to drive your fan, get either a 12v plugpack OR a 240v fan.
2. Mount 2 GPO's on the case & wire the outputs to them label 1 "heat" & the other "cool". it will be a much neater self contained unit & allow you to simply plug in the heater & plugpack/fan. Note you can't use a a double gpo as the outlets share the same wiring.


----------



## funkyyyy (11/7/11)

You're a lifesaver mate, the jiffybox and GPO's is such a good idea, I will use a 12v plugpack. So to connect that to the fans (4 Pin molex (+ / - & Ground x 2) I use cut the end of the plug pack and use a wire joiner to connect the wires from the fans to the plug pack? I'm using two fans, how would I go about running two off of the 1 plug pack. Cheers


----------



## adniels3n (11/7/11)

If the mA rating of the plug pack is more than the 2 fans combined, it'll be ok. Should be written on them.
You understand that the heating /cooling outputs are the active wire only? ie. 240VAC active is joined from 1 onto 5 & 7, waiting to turn on & supply power out of 6 & 8.
The Heating/Cooling circuits Neutral returns back to 2.


----------



## funkyyyy (11/7/11)

Thanks, I'll look into that. And yeah It makes sense to me now, I originally mis-understood the temp controller but now I will use this wiring diagram:


----------



## DJR (11/7/11)

Fans don't really cool at all, they will just equalize the inside to whatever the ambient temperature is.

I'd look at a peltier element which has a "cold" and "hot" side - a kind of solid state fridge. Put a heatsink on the "hot" side and blow your fans into that, the peltier will pull heat energy out of the cabinet and discharge it on the other side with the heat sink and fans.

Lots of small wine coolers use peltiers as they are cheap, but not as efficient as a compressor.

Edit: Fans will cool if you evaporate water as well, the evaporation of water will remove heat, look up evaporative coolers and you might be able to do that too.


----------



## Malted (11/7/11)

Watch out that you don't get this situation: cold = condensation = wet guitar = dead guitar


----------



## crozdog (11/7/11)

DJR said:


> Fans don't really cool at all, they will just equalize the inside to whatever the ambient temperature is.
> 
> I'd look at a peltier element which has a "cold" and "hot" side - a kind of solid state fridge. Put a heatsink on the "hot" side and blow your fans into that, the peltier will pull heat energy out of the cabinet and discharge it on the other side with the heat sink and fans.
> 
> ...



Peltiers are a great idea but they will draw more current than a plug pack will supply - a modified ATX PSU would handle the current easily. As DJR says they are cheap - look on ebay for "Thermoelectric Cooler"!

I'd put a fan on the cold side too to distribute the "cold" through the cabinet.

Re running 2 fans off the 1 supply - like mudzzy says, as long as the total current draw of the 2 fans is less than your supply can handle, simply connect (join) the 2 fans to the 1 supply.


----------



## funkyyyy (12/7/11)

Would this do the trick?

http://www.ebay.com.au/itm/THERMOELECTRIC-...=item2c5db435c9


So attaching a heat-sink on the "Hot" side and a fan on the "Cold" side to push the cold air back into the cabinet? How efficient would one of these be to cool a cabinet that is 1365x555x150mm? And you think running these off of the power supply would work better? My ATX power supply plugged into the female plug of the cooling on the jiffy box will switch on automatically (providing the green and a black earth wire are joined together - switching the PSU on permanently) to power the Peltier and Fans, Running off of the 12V wires on the Power supply? Sorry if that sounds confusing lol.

Thanks


----------



## Doogiechap (12/7/11)

Hi Funkyyyyy,
Good on you for getting in to this a bit more deeply 
Peltier wise I can't comment formally on it capacity or ability to cool that capacity (thermodynamics is too tough for my head) but I don't think it would make a huge impact but certainly better than nothing at all. I guess you might be able to buy a heatsink with enough area to fit two peltiers and then grab another if you are unhappy with the performance. Your ATX may be unhappy starting up under load and if that is the case then you can ditch the GPO for the cooling side and just run the +ve 12V wire of your ATX PSU via pins 7&8 of your controller and leave it running the whole time. Have a sniff around google and you might find it an advantage in providing some loading on the other rails (outputs) of the ATX. This will help it to run with more stability and possibly give a better output particularly if you do end up running two peltiers with a capacity to draw 6 amps each.
Good luck and keep us posted on how you go !
Cheers
Doug


----------



## funkyyyy (12/7/11)

Ah yes I thought of that initially however this PSU must start up under peak load from at least 90VAC however if it doesn't like it I will just run it directly out of the thermostat itself although I don't think that it will be an issue. As for running the Power supply under load to get better stability, I will be running at least one peltier, 3 fans and some lighting off of different rails. I'm not sure if this current draw will be enough to maintain stability but I am quietly confident it will be


----------



## mgill (12/7/11)

A couple of quick notes when using peltiers. Peltiers are a heat pump, i.e. they will transfer the heat from one side of the plate to the other. So essentially you can have the peltier heat or cool depending on what polarity the voltage is plate 1 will get hot and plate 2 will get cold, swap the polarity and plate 1 will cool while plate 2 gets hot. I am not sure about the controller you have but a lot of controllers will allow you to have two set points (one for heating and one for cooling) or an adjustable timeout to switch between heating and cooling. If this is the case with this controller you could set it up to switch between heating and cooling by adding 2 240V DPDT relays (if you do it in parallel with the GPO's you are wiring in you could have a 12V and a 240V output option. The peltiers are very sensitive to swapping between heating and cooling and the two plates need to be around the same temperature when you do so, so if you plan on doing something along these lines make sure that you can have a delay or two different temperature set points. The other thing to note is although computer power supplies have a high wattage rating, this is a total wattage divided into the other rails as well (15V -15V 12V 5V etc). So you may want to look at a lower wattage peltier (you can get 40W modules from jaycar for about $15).


----------



## funkyyyy (16/7/11)

I just finished wiring up the STC-1000 inside of the box and I must say it has worked out brilliantly. Now just need to wire my heating / cooling devices to the male socket and mount it in the cabinet and I'm done. Here's a pic of my progress so far:







Thank you SO much for all your help guys, I appreciate it!


----------



## crozdog (18/7/11)

funkyyyy said:


> I just finished wiring up the STC-1000 inside of the box and I must say it has worked out brilliantly. Now just need to wire my heating / cooling devices to the male socket and mount it in the cabinet and I'm done. Here's a pic of my progress so far:
> 
> 
> Thank you SO much for all your help guys, I appreciate it!



Keep the progress pics coming. good work.

don't forget to document it ;-)


----------



## funkyyyy (19/7/11)

Thanks mate, yeah definatley, this will thicken up my folio 

I have a quick question on peltiers. I just ordered a 40x40mm one off of ebay from a guy in WA.. here are the specs:

"Operates from 0~15.2V DC and 0~6A
Operates Temperature: -30 to 70C
Max power consumption: 60 Watts"

So I'm assuming that you put a heat-sink on the hot side and a fan pushing the cold air out from the cold side? I'm just going to wire this up to the ATX power supply and use it as an inverter seeing as it's readily available =)


----------



## crozdog (19/7/11)

funkyyyy said:


> Thanks mate, yeah definatley, this will thicken up my folio
> 
> I have a quick question on peltiers. I just ordered a 40x40mm one off of ebay from a guy in WA.. here are the specs:
> 
> ...



I personally haven't made anything with peltiers but believe that you will need a fan on the hot side to help remove the heat. This link has some info you might find useful http://labjack.com/blog/end-table-drink-cooler


----------



## funkyyyy (21/7/11)

Thermostat unit all wired up and completed, ready for heating & cooling devices to be assembled (waiting on peltiers lol). Here are some pics  Just a quick question though - I'm using a 150w ceramic lamp that fits in a socket (like a normal light bulb socket) and it has two contacts for wiring which are not labelled. How do I wire this up to the 240? Just two live wires in a circuit to and from the outlet? Or do I need a neutral and live wire.. thanks


----------



## mgill (21/7/11)

definately put a fan on the hot side, and if you want to protect the peltier from possible damage you would be best to wire a thermostat onto the positive wire to stop power going to it if it gets above a specific temperature (in this case it says maximum operating temperature 70 degrees) http://www.jaycar.com.au/productView.asp?I...mp;form=KEYWORD. Simply cut the red wire to the peltier and stick this device in between. then mount the device to the "hot" heatsink. It may be $5, but it is good insurance against killing the peltier and the pain of waiting for a new one to arrive.

Another important thing to note is insulation. You will increase the effieciency dramatically if you make sure you have good insulation between the "hot" heat sink and the "cold" heat sink, so i would make sure you get some polystyrene foam and sandwich in between the gap of the two heat sinks (an air gap is a very poor insulator and as such the two heat sinks will try and equalise the temperature between them.

I am in the middle of a building a PC based temperature controller with built in alcohol sensor for my homebrew system which I am utilising the peltiers for... so i have done a fair bit of research on them.

More than willing to help out if you have any issues, its good to see your enthusiasm.


----------



## funkyyyy (21/7/11)

Great idea mate, I'll go pick one up tomorrow. I'm a really big noob with peltiers, basically I ordered two (specs listed above). I am going to mount an AMD heatsink/fan with some arctic silver 5 (thermal compound) inbetween the hot side and the heat sink. To move the cold air coming from the other side, I thought of getting some sort of tubing lined with aluminum foil or something, with a fan at the end sucking the cold air out into the cabinet. I noticed you were mentioning "cold" side heatsink, am I supposed to mount a heatsink on both sides of the peltier?

Thanks


----------



## kelbygreen (21/7/11)

ok I have to be honest I havnt read threw this entire thread. But on peltiers you have to get the volage right (well with CPU's as I researched) as not enough watts and it wont work properly and to much watts and it can freeze the cpu. But with my cpu phenom II they over clocked to 6.3ghz using dry ice so I guess cooling isnt the issue where old amd cpu wouldnt take - temps to well. for your case I got no real insite but seems like people in here have some idea


----------



## kelbygreen (21/7/11)

ok funky read your last post there is a hot side and a cold side if you want to cool something you put it on the cool side it draws the heat threw to to hot side where the heat sink is (hence the name) the fan will go on the hot side as well to cool the heat sink and cool it down a bit as for the direction of flow on it I am not sure if its best to push air threw the heat sink which may push hot air onto where you are cooling or draw the hot air away from the heat sink and push it out. blowing cold air onto hot parts works better but it its going to blow hot air onto the part you are cooling it may be less efficient so drawing the hot air away may be the go as it will suck cool air in from the sides rather then blow cool air directly on it


----------



## mgill (21/7/11)

funkyyyy said:


> Great idea mate, I'll go pick one up tomorrow. I'm a really big noob with peltiers, basically I ordered two (specs listed above). I am going to mount an AMD heatsink/fan with some arctic silver 5 (thermal compound) inbetween the hot side and the heat sink. To move the cold air coming from the other side, I thought of getting some sort of tubing lined with aluminum foil or something, with a fan at the end sucking the cold air out into the cabinet. I noticed you were mentioning "cold" side heatsink, am I supposed to mount a heatsink on both sides of the peltier?
> 
> Thanks




No you don't have to mount a heatsink on the cold side, however you will increase the efficiency of the peltier slightly if you draw the temperature away from the plates quicker. I have used a fan based heat sink before for my applications but that has only been on the "heating" side of the peltier as I have wanted to cool to lower temperatures and the peltiers will only cool to about 25 degrees below ambient temperature (you can stack them on top of each other to increase the temperature they will cool down to but it dramatically reduces there efficiency.You can buy heat sinks which join together to form a square section which an 80mm fan can mount to (similar to what you are thinking of doing with tubing) I would definately try and draw the cool air off the peltier with some form of heat sink though. I used 2 of these for my current project (but that is major overkill) http://www.jaycar.com.au/productView.asp?I...mp;form=KEYWORD. I would just stick with a small fan/heatsink combo for the cooling side like you find for CPU's in computers. Is it a tightly seald enclosure you are making? Cause you will definately need to be careful of condensation and moisture if it isn't


Keep up the good work mate, your control unit looks really good, a very professional finish.


----------



## funkyyyy (21/7/11)

kelbygreen said:


> ok funky read your last post there is a hot side and a cold side if you want to cool something you put it on the cool side it draws the heat threw to to hot side where the heat sink is (hence the name) the fan will go on the hot side as well to cool the heat sink and cool it down a bit as for the direction of flow on it I am not sure if its best to push air threw the heat sink which may push hot air onto where you are cooling or draw the hot air away from the heat sink and push it out. blowing cold air onto hot parts works better but it its going to blow hot air onto the part you are cooling it may be less efficient so drawing the hot air away may be the go as it will suck cool air in from the sides rather then blow cool air directly on it



Ah yes I get you. The compartment in which the peltier will be housed is completely isolated from the rest of the cabinet (hence the tubing to transport the cold air into the space I wish to heat / cool) So I don't need to worry about blowing the warm air back into the cabinet.


----------



## funkyyyy (21/7/11)

mgill said:


> No you don't have to mount a heatsink on the cold side, however you will increase the efficiency of the peltier slightly if you draw the temperature away from the plates quicker. I have used a fan based heat sink before for my applications but that has only been on the "heating" side of the peltier as I have wanted to cool to lower temperatures and the peltiers will only cool to about 25 degrees below ambient temperature (you can stack them on top of each other to increase the temperature they will cool down to but it dramatically reduces there efficiency.You can buy heat sinks which join together to form a square section which an 80mm fan can mount to (similar to what you are thinking of doing with tubing) I would definately try and draw the cool air off the peltier with some form of heat sink though. I used 2 of these for my current project (but that is major overkill) http://www.jaycar.com.au/productView.asp?I...mp;form=KEYWORD. I would just stick with a small fan/heatsink combo for the cooling side like you find for CPU's in computers. Is it a tightly seald enclosure you are making? Cause you will definately need to be careful of condensation and moisture if it isn't
> 
> 
> Keep up the good work mate, your control unit looks really good, a very professional finish.



So you think I should mount a heatsink on the cool side with a fan drawing the cool air away from the peltier into the cabinet? As for dimensions, it is 1365x550x150mm. A decent sized space, I wouldn't say tightly enclosed at all. Thanks mate, I'm real proud of it to be honest. I've been putting it through it's paces and so far its working like a charm.


----------



## mgill (21/7/11)

funkyyyy said:


> So you think I should mount a heatsink on the cool side with a fan drawing the cool air away from the peltier into the cabinet? As for dimensions, it is 1365x550x150mm. A decent sized space, I wouldn't say tightly enclosed at all. Thanks mate, I'm real proud of it to be honest. I've been putting it through it's paces and so far its working like a charm.




yeah, you definately want to try and keep those two sides of the peltier segregated and move the temperature away from it as quick as possible. I only wish i had seen your original post earlier. I have a USB interface board which I am using with some common electronic components to do a similar thing... read in temperature, turn on and off a peltier (and reverse polarity to it to make it either heat or cool a fermenter). I have also purchased an alcohol sensor which I have mounted into a modified airlock to constantly read in the alcohol concentration of the fermenter. The idea is I will take the data collected over a few brews, and see if I can correlate it to % alcohol in the fermenter. At minimum, I will be able to graph the fermentation process (temperature and alcohol reading for the whole brew and see the point where alcohol concentration no longer changes to determine that fermentation is complete) and control the temperature. I could have provided you with a parts list, schematic and some basic source code for software which you could have modified to suit your purposes, only trouble is you have already spent so much time effort and money on your current project.

I am currently rewiring the hardware at the moment off a protoyping board and into an enclosure and plan to have the first test done in a couple of weeks, at which stage I will write the graphing component of the software and see how well the peltiers perform!


----------



## NickB (21/7/11)

As for your bayonet fitting, there should be four screw terminals, one labeled E (Your Earth goes here), One labeled L (Loop - don't put anything here) and two unlabelled opposite each other. One of these is for your active, one for your neutral.

YMMV, as I'm not a qualified Electrician (yet), just a lowly apprentice.

Cheers


----------



## funkyyyy (22/7/11)

NickB said:


> As for your bayonet fitting, there should be four screw terminals, one labeled E (Your Earth goes here), One labeled L (Loop - don't put anything here) and two unlabelled opposite each other. One of these is for your active, one for your neutral.
> 
> YMMV, as I'm not a qualified Electrician (yet), just a lowly apprentice.
> 
> Cheers



My socket only has two screw terminals |: 

perhaps I picked up the wrong type?


----------



## mgill (23/7/11)

funkyyyy said:


> My socket only has two screw terminals |:
> 
> perhaps I picked up the wrong type?




All plastic? Are they labelled A and N?


----------



## funkyyyy (26/7/11)

mgill said:


> All plastic? Are they labelled A and N?



Yeah thats the one. Will it not work?

One of my peltiers arrived today, rigged it up to a heatsink + fan on the hot side, did some testing.

The cold side after 5 minutes reached -9.6C..

This is AMAZING results however there is one slight problem that was mentioned earlier in the thread.

I had frost on it.. condensation ey. How do I combat this? Without compromising too much temperature gain.


----------



## dmerrick (26/7/11)

The only sure fire way to prevent condesation is to maintain a temperature above the current dew point. To determine the dew point takes a fair few variables, but in a nutshell, high humidity = high dew point, low humidity = low dew point.


----------



## funkyyyy (26/7/11)

Roo_Brew said:


> The only sure fire way to prevent condesation is to maintain a temperature above the current dew point. To determine the dew point takes a fair few variables, but in a nutshell, high humidity = high dew point, low humidity = low dew point.



So you think putting a heatsink on the cold side with a fan ontop of it sucking the air from the cold side out into the cabinet would reduce this? Condensation inside of the cabinet isn't going to be an issue as the minimum temperature at which it will ever be set is way above any normal dew point (probably the lowest it will get is 10-15C.


----------



## funkyyyy (26/7/11)

Okay in the mean time I have drawn up a diagram of the final solution. I found a large heatsink from jaycar with no fan mounts, how do I go about attaching two fans to it? (to blow the cold air off of the heatsink into the case)

Thanks


----------



## NickB (26/7/11)

funkyyyy said:


> Yeah thats the one. Will it not work?



Your light fitting will work, it just won't be earthed, so make sure the rest of your system is earthed well - Because if a fault occurs in your fitting, there's no path for any fault current to run to earth. Take for example that your active wire becomes loose, or broken, and touches a metal part of the chassis of your enclosure. You'd want to make doubly sure you're correctly earthed, and running through the appropriate RCD.

Mind you, after flicking through the AS3000:2007 (Wiring Rules), I can't see exemptions anywhere for light fittings, meaning you would need a fitting with an earth point for your install to be to Australian Standard... I know that all new houses must have am earth run to every fitting.

Personally, I'd be getting a better fitting (what brand is the one you have??) form an electrical wholesaler or similar.


Cheers


----------



## funkyyyy (26/7/11)

NickB said:


> Your light fitting will work, it just won't be earthed, so make sure the rest of your system is earthed well - Because if a fault occurs in your fitting, there's no path for any fault current to run to earth. Take for example that your active wire becomes loose, or broken, and touches a metal part of the chassis of your enclosure. You'd want to make doubly sure you're correctly earthed, and running through the appropriate RCD.
> 
> Mind you, after flicking through the AS3000:2007 (Wiring Rules), I can't see exemptions anywhere for light fittings, meaning you would need a fitting with an earth point for your install to be to Australian Standard... I know that all new houses must have am earth run to every fitting.
> 
> ...



There is no chance of it touching any metal as the entire encloser is made of tasmanian oak.

As for what brand, its a cheapie from Hong Kong. I will go and purchase one with a ground =)


----------



## crozdog (26/7/11)

funkyyyy said:


> how do I go about attaching two fans to it? (to blow the cold air off of the heatsink into the case)


long screws or bolts? cable ties have been used for all sorts of things ;-)


----------



## funkyyyy (26/7/11)

crozdog said:


> long screws or bolts? cable ties have been used for all sorts of things ;-)



Ah yes I'm going to have to find some screws thin enough to fit through the fins, or drill through the fins. Ha. Zip ties could work too, I used a few of them in the wiring of my thermostat =D


----------



## NickB (26/7/11)

funkyyyy said:


> There is no chance of it touching any metal as the entire encloser is made of tasmanian oak.
> 
> As for what brand, its a cheapie from Hong Kong. I will go and purchase one with a ground =)




That explains it then. Those HK cheapies are likely not even to Aus Standard. Not sure how they can import them! Good idea getting a better quality unit. Even an HPM or similar from the Green Shed will suffice. As they say, you only get once chance with 240v....

Cheers


----------



## funkyyyy (26/7/11)

NickB said:


> That explains it then. Those HK cheapies are likely not even to Aus Standard. Not sure how they can import them! Good idea getting a better quality unit. Even an HPM or similar from the Green Shed will suffice. As they say, you only get once chance with 240v....
> 
> Cheers



Yeah there is such a mass of them on ebay. Although some of the cheap stuff coming out of there is great, my temperature controller came from HK. It was only $27AU and it works like a dream. Agreed, This is my first time messing with 240, and so far so good it's been great and worked well. I'd rather not blow it all from a crappy import bayonet socket, lol.


----------



## mgill (27/7/11)

funkyyyy said:


> So you think putting a heatsink on the cold side with a fan ontop of it sucking the air from the cold side out into the cabinet would reduce this? Condensation inside of the cabinet isn't going to be an issue as the minimum temperature at which it will ever be set is way above any normal dew point (probably the lowest it will get is 10-15C.




if average temperature is 25 celcuis and humidity is 75% (not uncommon in summer) then you will see a dew point around 20 degrees celcius. You may want to look at some weather observations for your region and compare average humidity and temperature. If however you have an airtight case for the housing, you will be introducing no extra water vapour into the air under which you sealed the case. To further reduce the amount of water vapour, you could add a bag of silica gel.


----------



## mgill (27/7/11)

funkyyyy said:


> Okay in the mean time I have drawn up a diagram of the final solution. I found a large heatsink from jaycar with no fan mounts, how do I go about attaching two fans to it? (to blow the cold air off of the heatsink into the case)
> 
> Thanks




If your controller has a timeout delay or two set points you can use the Peltier to do both the heating and cooling thereby eliminating the need for the ceramic heater (All you need is 2 x 240V relays, which you use to switch the polarity of the voltage to the peltier). Do you have a specification sheet for your controller?

If it doesn't you are going to be rapidly switching between heating and cooling constantly, and you will more than likely sit on the higher side of you temperature set point given that it is far more efficient to heat than cool and your cooling capacity is quite limited.


----------



## Filby (27/7/11)

funkyyyy said:


> Thermostat unit all wired up and completed, ready for heating & cooling devices to be assembled (waiting on peltiers lol). Here are some pics  Just a quick question though - I'm using a 150w ceramic lamp that fits in a socket (like a normal light bulb socket) and it has two contacts for wiring which are not labelled. How do I wire this up to the 240? Just two live wires in a circuit to and from the outlet? Or do I need a neutral and live wire.. thanks




Funky, where did you get the panel mount sockets? Ive had a look in a few electrical stores without any luck.

Cheers

Fil


----------



## gap (27/7/11)

Jaycar.

Regards

Graeme


----------



## funkyyyy (27/7/11)

mgill said:


> if average temperature is 25 celcuis and humidity is 75% (not uncommon in summer) then you will see a dew point around 20 degrees celcius. You may want to look at some weather observations for your region and compare average humidity and temperature. If however you have an airtight case for the housing, you will be introducing no extra water vapour into the air under which you sealed the case. To further reduce the amount of water vapour, you could add a bag of silica gel.



I should mention, there will be another "shelf" of wood surrounding the large heatsink so the fans sit flush with the base of the cabinet. I will extend the tubing for the heating, or raise the bulb / fan to compensate for the higher floor in the cabinet. I was thinking of insulating the void in between the two shelves with some polystyrine, or as you said, silica gel bags found in those small dehumidifiers. Thanks 



mgill said:


> If your controller has a timeout delay or two set points you can use the Peltier to do both the heating and cooling thereby eliminating the need for the ceramic heater (All you need is 2 x 240V relays, which you use to switch the polarity of the voltage to the peltier). Do you have a specification sheet for your controller?
> 
> If it doesn't you are going to be rapidly switching between heating and cooling constantly, and you will more than likely sit on the higher side of you temperature set point given that it is far more efficient to heat than cool and your cooling capacity is quite limited.



I know what you mean, I was taking that into consideration however as far as I know my temp controller does not have the ability to do this, I'd rather keep the setup with the ceramic bulb, as in efficient as it may be switching between power constantly, I just need something that works. The whole thing is due in 5-6 weeks, I am going to perfect it for home use after that  Here is the data sheet for the controller, just scroll down the page and all the info is there:

http://www.ebay.com.au/itm/All-purpose-Tem...=item2312886353

Cheers guys


----------



## mgill (27/7/11)

funkyyyy said:


> I should mention, there will be another "shelf" of wood surrounding the large heatsink so the fans sit flush with the base of the cabinet. I will extend the tubing for the heating, or raise the bulb / fan to compensate for the higher floor in the cabinet. I was thinking of insulating the void in between the two shelves with some polystyrine, or as you said, silica gel bags found in those small dehumidifiers. Thanks
> 
> 
> 
> ...



It has two functions, one to set the temperature difference (i.e if you set it to 0.5 degrees and you had a set point of 16 it would cool at 15.5 and cool at 16.5) the other one is called condensor setting, which will delay the time before it starts an action again, i.e. it heats to the set point, turns off for say 5mins before it looks at the temperature again and either heats or cools.

So if you desired you could remove the ceramic heater, and use two relays to swap the polarity of the Peltier to force it to either heat or cool, due to the lack of heating/cooling capacity of the peltier, it will allow for a much smoother temperature control.

If you want to go down this path, I would look at 2x240VAC relays which are DPDT http://www.jaycar.com.au/productView.asp?I...;SUBCATID=979#1, If you want to go down this path I will do a quick picture on how to wire them up.


----------



## Deebo (27/7/11)

Anyone know if it is neccesary to drill cooling holes into the stc-1000 enclosure? (I just wired mine up and remembering hearing people say they got pretty warm?)


----------



## RdeVjun (27/7/11)

:icon_offtopic: 
Pardon the gratuitous poor taste and apologies in advance if it causes offence- pretty sure that's not an accurate diagram of the 'final solution', although, feck it up and you might come close.


----------



## mgill (27/7/11)

Deebo said:


> Anyone know if it is neccesary to drill cooling holes into the stc-1000 enclosure? (I just wired mine up and remembering hearing people say they got pretty warm?)




Looking at the specification sheet supplied by the ebay store power dissipation is pretty low (3W) and its operating temperature is 0-60c. You should be able to get away with it, but if you feel that it is running hot, there is no harm in drilling a couple of holes... if possible always try and aim for cross ventilation.


----------



## funkyyyy (27/7/11)

mgill said:


> It has two functions, one to set the temperature difference (i.e if you set it to 0.5 degrees and you had a set point of 16 it would cool at 15.5 and cool at 16.5) the other one is called condensor setting, which will delay the time before it starts an action again, i.e. it heats to the set point, turns off for say 5mins before it looks at the temperature again and either heats or cools.
> 
> So if you desired you could remove the ceramic heater, and use two relays to swap the polarity of the Peltier to force it to either heat or cool, due to the lack of heating/cooling capacity of the peltier, it will allow for a much smoother temperature control.
> 
> If you want to go down this path, I would look at 2x240VAC relays which are DPDT http://www.jaycar.com.au/productView.asp?I...;SUBCATID=979#1, If you want to go down this path I will do a quick picture on how to wire them up.



If I take this route will the cooling / heating effect work? I know it won't be as fast as using a ceramic heater but that is not a problem, just as long as it can reach the desired temperature. The temperature range I'm aiming for won't exceed 13-15C and 30-35C. I also have never used "relays" before and have almost zero understanding on them. So if using them instead of the ceramic heater is the better option, I'm all ears mate


----------



## mgill (27/7/11)

funkyyyy said:


> If I take this route will the cooling / heating effect work? I know it won't be as fast as using a ceramic heater but that is not a problem, just as long as it can reach the desired temperature. The temperature range I'm aiming for won't exceed 13-15C and 30-35C. I also have never used "relays" before and have almost zero understanding on them. So if using them instead of the ceramic heater is the better option, I'm all ears mate




thats the path i would go down. I would make sure the module does what it says (function 2 and function 3) Function 2 is your temperature difference default and function 3 is your timeout delay temperature difference is set to 0.5 degrees and compressor timeout is set to 3 minutes, these look like good values, it won't heat or cool if the temperature is within 0.5 degrees of your set point, and the minimum time within which it will switch from heating to cooling and vice versa is 3 minutes (should give enough time for the two sides of the peltier to stabilise to close to the same temperature.

I will draw up a quick schematic tomorrow and scan for you as to how you would hook it up... the whole system will have a fairly slow rate at which the temperature changes so you may find that you could adjust the function 2 and function 3 parameters to tune the system better.


----------



## funkyyyy (27/7/11)

mgill said:


> thats the path i would go down. I would make sure the module does what it says (function 2 and function 3) Function 2 is your temperature difference default and function 3 is your timeout delay temperature difference is set to 0.5 degrees and compressor timeout is set to 3 minutes, these look like good values, it won't heat or cool if the temperature is within 0.5 degrees of your set point, and the minimum time within which it will switch from heating to cooling and vice versa is 3 minutes (should give enough time for the two sides of the peltier to stabilise to close to the same temperature.
> 
> I will draw up a quick schematic tomorrow and scan for you as to how you would hook it up... the whole system will have a fairly slow rate at which the temperature changes so you may find that you could adjust the function 2 and function 3 parameters to tune the system better.



Thanks mate, I really appreciate it. I actually had been messing with Function 3 when I first fired up the temp controller and was scratching my head as to why the cooling output wasn't working (it was, just wouldn't turn on untill 4 minutes) .. I ended up rewiring the whole thing before I gave up and consulted the instructions. Ha. Glad to see it finally has a use, I look forward to seeing the diagram. I live right up the road from a brand new Jaycar. Slow temperature change isn't really an issue for me, just as long as it happens.


----------



## mgill (27/7/11)

funkyyyy said:


> Thanks mate, I really appreciate it. I actually had been messing with Function 3 when I first fired up the temp controller and was scratching my head as to why the cooling output wasn't working (it was, just wouldn't turn on untill 4 minutes) .. I ended up rewiring the whole thing before I gave up and consulted the instructions. Ha. Glad to see it finally has a use, I look forward to seeing the diagram. I live right up the road from a brand new Jaycar. Slow temperature change isn't really an issue for me, just as long as it happens.



Nice and convenient then... I worked at a Jaycar for a few years when I was at uni so i tended to either do a lot of little projects like this or be involved in helping a lot of people with projects like this. Only downside is that trying to get help out of half the staff members there these days is very hard, either they don't know what they are talking about, or they aren't willing to divulge any information due to fear of liability.


----------



## funkyyyy (27/7/11)

mgill said:


> Nice and convenient then... I worked at a Jaycar for a few years when I was at uni so i tended to either do a lot of little projects like this or be involved in helping a lot of people with projects like this. Only downside is that trying to get help out of half the staff members there these days is very hard, either they don't know what they are talking about, or they aren't willing to divulge any information due to fear of liability.



I wouldn't mind a job there next year for my Gap year.. the shop we have is run by a few incompetent people who seem to always be playing with the remote control helicopters and what not. I refuse to ask for professional advice there after one of them tried to sell me thin guage wire that was rated at a MAXIMUM of 12.8V @ 6-8A and pass it off as 220VAC compliant, simply because he looked at the wiring diagram I had for the temp controller (Blue, brown and green for the N, L and E) and compared it to the colours he had on the 12v wiring. Rant over, anyway I have one more question before switching my project down this road.

I know the peltiers I have (rated at 60w) get VERY cold, how efficient will they be at transferring the heat from the hot side, through the large heatsink to the fans to blow this warmth into the cabinet? (Mind you, the dimensions are only 1365x545x150.. subtracking 300mm off of the length to house the electronics..


----------



## mgill (27/7/11)

funkyyyy said:


> I wouldn't mind a job there next year for my Gap year.. the shop we have is run by a few incompetent people who seem to always be playing with the remote control helicopters and what not. I refuse to ask for professional advice there after one of them tried to sell me thin guage wire that was rated at a MAXIMUM of 12.8V @ 6-8A and pass it off as 220VAC compliant, simply because he looked at the wiring diagram I had for the temp controller (Blue, brown and green for the N, L and E) and compared it to the colours he had on the 12v wiring. Rant over, anyway I have one more question before switching my project down this road.
> 
> I know the peltiers I have (rated at 60w) get VERY cold, how efficient will they be at transferring the heat from the hot side, through the large heatsink to the fans to blow this warmth into the cabinet? (Mind you, the dimensions are only 1365x545x150.. subtracking 60mm off of the length to house the electronics..




With this solution you will only have one side transferring a temperature change into your cabinet. There is no specific hot or cold side to a peltier, the sides will be either hot or cold depending on which way you hook the voltage up to them. You can test this if you want, connect the peltier up to a 12V supply (red to red, black to black) see which side gets hot, make a note of it... now let the peltier cool down so the both sides are the same temperature (important as you don't really want to switch from heating to cooling if there is a large temperature difference between the two plates (hence your function 2 and 3 settings should take care of this). Once its has cooled to room temperature try changing the polarity red wire to black (negative) and black wire to red (positive). The side which was hot will now get cold. So all you will need to do is let the air blow in from one side of the peltier and exhaust the other side out into the room. The heating capacity will be greater than the cooling capacity of the peltier as the devices are not very efficient at cooling (low efficiency and conservation of energy means the energy will be lost through heat).
The effieciency of moving the temperature controlled air around will be pretty much the same whether it is heating or cooling so I wouldn't be too concerned about that. Only other downside is if you are using a thermal circuit breaker on the heatsink, you may want to put one on both heatsinks although I don't envisage they will reach these temperatures.


----------



## funkyyyy (27/7/11)

mgill said:


> With this solution you will only have one side transferring a temperature change into your cabinet. There is no specific hot or cold side to a peltier, the sides will be either hot or cold depending on which way you hook the voltage up to them. You can test this if you want, connect the peltier up to a 12V supply (red to red, black to black) see which side gets hot, make a note of it... now let the peltier cool down so the both sides are the same temperature (important as you don't really want to switch from heating to cooling if there is a large temperature difference between the two plates (hence your function 2 and 3 settings should take care of this). Once its has cooled to room temperature try changing the polarity red wire to black (negative) and black wire to red (positive). The side which was hot will now get cold. So all you will need to do is let the air blow in from one side of the peltier and exhaust the other side out into the room. The heating capacity will be greater than the cooling capacity of the peltier as the devices are not very efficient at cooling (low efficiency and conservation of energy means the energy will be lost through heat).
> The effieciency of moving the temperature controlled air around will be pretty much the same whether it is heating or cooling so I wouldn't be too concerned about that. Only other downside is if you are using a thermal circuit breaker on the heatsink, you may want to put one on both heatsinks although I don't envisage they will reach these temperatures.




Yeah I get what you mean with the polarity, all I really need to find out is if the set up will say... heat the air to 30C and cool it to maybe 15-16C. Are these realistic figures for two 60w peltiers?


----------



## mgill (27/7/11)

funkyyyy said:


> Yeah I get what you mean with the polarity, all I really need to find out is if the set up will say... heat the air to 30C and cool it to maybe 15-16C. Are these realistic figures for two 60w peltiers?




yep, easily achievable.


----------



## funkyyyy (27/7/11)

mgill said:


> yep, easily achievable.



Thanks for yourhelp bro, if/when you get around to the schematics, I look forward to seeing them / learning about how the relay works.


----------



## dmerrick (27/7/11)

Yes and no, peltiers work on a temperature differential, so a 15 degree differential is well within the specs of even a small cell. However, your volume will be the determining factor, the air is going to be the downside, its bad as a heat mass. Not trying to rain on your parade, it will work, but don't look for any real efficiency.

And like Mgill said, they're polarity dependant, whixh is kinda cool if you want to do true temperature control, rather than just switch the positive you can swap polarity and go the other way.


----------



## funkyyyy (27/7/11)

Roo_Brew said:


> Yes and no, peltiers work on a temperature differential, so a 15 degree differential is well within the specs of even a small cell. However, your volume will be the determining factor, the air is going to be the downside, its bad as a heat mass. Not trying to rain on your parade, it will work, but don't look for any real efficiency.
> 
> And like Mgill said, they're polarity dependant, whixh is kinda cool if you want to do true temperature control, rather than just switch the positive you can swap polarity and go the other way.




Yeah I completely agree with you, well aware these little things are not going to be instantly heating my enclosure or heating any large space efficiently, but seeing as my space is relatively small and this is just a school (HSC) based project I am willing to settle for something that may not be super efficient, but works to an extent


----------



## mgill (28/7/11)

funkyyyy said:


> Thanks for yourhelp bro, if/when you get around to the schematics, I look forward to seeing them / learning about how the relay works.




This should do the trick, the wiring of those relays doesn't quite match up with the ones available from Jaycar but they should have a picture on them which follows the attached relay format, if it doesn't take a snap of them and I will point out which wire is which (you gotta get it right as if you don't and you have the condition where both relays are in the off position they will try and short circuit the ATX power supply).


----------



## funkyyyy (28/7/11)

mgill said:


> This should do the trick, the wiring of those relays doesn't quite match up with the ones available from Jaycar but they should have a picture on them which follows the attached relay format, if it doesn't take a snap of them and I will point out which wire is which (you gotta get it right as if you don't and you have the condition where both relays are in the off position they will try and short circuit the ATX power supply).
> View attachment 47312



I appreciate what you have done for me, I'm having limitations with understanding the whole diagram though. Does this mean I have to re-wire my temp controller unit? Or will this work directly out of the flat panel mount female sockets for cooling / heating. Sorry, I've never messed with diagrams like that. It's all a bit of a jumble for me ha.


----------



## mgill (28/7/11)

funkyyyy said:


> I appreciate what you have done for me, I'm having limitations with understanding the whole diagram though. Does this mean I have to re-wire my temp controller unit? Or will this work directly out of the flat panel mount female sockets for cooling / heating. Sorry, I've never messed with diagrams like that. It's all a bit of a jumble for me ha.



you can modify it to suit the sockets. Will update the drawing for you.


----------



## funkyyyy (28/7/11)

mgill said:


> you can modify it to suit the sockets. Will update the drawing for you.



Thanks bud

I definitely owe ya one haha


----------



## mgill (29/7/11)

funkyyyy said:


> Thanks bud
> 
> I definitely owe ya one haha



This should do the job, standard wiring to plugs, you will however need to run a seperate power into your case for the atx supply. Remember for the relays you need to make the connections on the Normally Open side (N/O) to switch the 12V supply otherwise, when the controller is in a state of not heating or not cooling both relays would be trying to switch the power through and since they swap the polarity they will short out.


----------



## funkyyyy (22/8/11)

A quick progress update for anyone who is interested. Last week of construction, nearly there. Just need to clamp and glue the whole thing and give it a stain and some glass door. Also have a brushed aluminum panel to cover all of the electronics. The system works a beaut, when cold is on the large fan glows blue, when it's heating the smaller fan glows red.
















As you can see if you followed earlier in the thread the design layout has been altered slightly with the cooling and heating components on opposite sides to the original idea. This allowed me to attach a very large heatsink to the peltier with a fan drawing the cold air off of it out into the cabinet. It works great! Thanks again for the help with electronics, I appreciate it immensely.


----------



## adniels3n (22/8/11)

Well done young Sir. You will go a long way in a related field if you choose to pursue it. You'll also live life always needing a bigger set of drawers for all these various lengths of coloured wire & fans & motors & gears & broken things you will need one day.....


----------



## funkyyyy (22/8/11)

Muddzy said:


> Well done young Sir. You will go a long way in a related field if you choose to pursue it. You'll also live life always needing a bigger set of drawers for all these various lengths of coloured wire & fans & motors & gears & broken things you will need one day.....




Thanks mate I appreciate it, parents have already dedicated the closet under the stairs for all my "things".. various boxes of computer components lol, will be studying electrical engineering at uni next year, cannot wait.


----------



## funkyyyy (24/8/11)

Nearly there. (Only half of the electronics are in) I opted for a Navy Blue felt lining instead of black.. was rather easy to do, screw in back and just cut to size and used spray adhesive all over the ply and ironed it out. Came out great! Getting the door fit tomorrow morning. Going to give it a light polyurethane coat.


----------

