Tight Arse Stir Plate

[Banshee]

HEHEHE, exactly what I was thinking!

Any electronics kit will be a bit to advanced for me by the looks of things.

That's why I was hoping for that PWM thingy to come and be a part I just buy and plug in


thanks
Bjorn

This would probably suit you best. Looks like a unit all you have to do is attach a dial pot and the power in socket wires and the fan wires.

http://cgi.ebay.com.au/LM317-DC-AC-4V-30V-...DefaultDomain_0

 

[beerbrewer76543]

Correct me if I am wrong but isn't the blue box on that board a multi turn adjustable pot for controlling voltage?

 

[Banshee]

Correct me if I am wrong but isn't the blue box on that board a multi turn adjustable pot for controlling voltage?

Thats true but what good is the pot in the box?
Are you going to open your case every time you want to adjust your speed?
If you want to set and leave sure, but as you increase in flask and volume size you will want to alter your pot adjustment so for ease remove the trimpot and wire in a stand alone dial type pot.

 

[beerbrewer76543]

Sounds good. Any idea of the resistive value of the blue trim pot already on that board?

Cheers

 

[SJW]

I have been away from this site for what feels like years, maybe it has, but I can't believe that this old thread was STILL at the top of the list.
Reminds me of the ol "NO CHILL METHOD" and "USERS OF THE NO CHILL METHOD" threads, that was a killer.

Steve

 

[BjornJ]

This would probably suit you best. Looks like a unit all you have to do is attach a dial pot and the power in socket wires and the fan wires.

http://cgi.ebay.com.au/LM317-DC-AC-4V-30V-...DefaultDomain_0

Banshee,
appreciate you taking the time to help!

I have bookmarked the relisted version of that item, want to ask a question here before buying it.
Sorry for being somewhat slooow on the subject, but this talk of stripping this and that out and putting in a pot here and there makes me worried

Q:
If I buy this thing from China, can I put it in a project box from Jaycar, connect the two wires from the 12 V power supply in one end and the wires to the 12 V computer fan in the other.
Then drill a hole in the project case and use a screw driver to adjust the fan speed by turning the little screw on the blue piece in the picture?

(I have the on/off button, the project box, fan, power supply, magnets, stir bar, etc from my first two attempts which failed miserably)





If so, I want one!

thanks
Bjorn

 

[BjornJ]

...I'm so bad at waiting..

I ordered one now, let's hope it works.


thanks again,

Bjorn

 

[Banshee]

Q:
If I buy this thing from China, can I put it in a project box from Jaycar, connect the two wires from the 12 V power supply in one end and the wires to the 12 V computer fan in the other.
Then drill a hole in the project case and use a screw driver to adjust the fan speed by turning the little screw on the blue piece in the picture?

(I have the on/off button, the project box, fan, power supply, magnets, stir bar, etc from my first two attempts which failed miserably)




thanks
Bjorn

For the fan wire straight into the output sockets.
For the input go to Jaycarand buy a 12v power socket and drill a hole in your box and secure the socket on the inside wire to the circut boards input sockets and solder to the 12v power socket.
Yes you can drill a hole and use a screwdriver to adjust the onboard pot.

 

[Banshee]

You can strip the wires on your 12v power pack, but then it is dedicated for this unit only. With the socket the power pack can be use universaly.

 

[BjornJ]

Thanks again for clearing it up.

will give it a go as soon as it gets here.

thanks
Bjorn

 

[Wolfy]

dude, you need a fan speed controller from any computer store.

As per my posts (and pictures) on the previous page, I have to say I agree with this.
It could not be easier than a speed-controlled fan from a computer store and an old 2nd hand 12V power supply (mobile phone charger or similar).
No need for messing around with electronics or other bits, no need to solder or for circuit boards, pots etc.

 

[BjornJ]

As per my posts (and pictures) on the previous page, I have to say I agree with this.
It could not be easier than a speed-controlled fan from a computer store and an old 2nd hand 12V power supply (mobile phone charger or similar).
No need for messing around with electronics or other bits, no need to solder or for circuit boards, pots etc.

Sorry, didn't mean to ignore this answer, just forgot to go back and reply.

I tried this version, I bought on ebay a fan controller which was one of those pieces of steel that fits in the expansion slots in the back of the chassis. It connects to power on the motherboard and then to the computer fan, and has a potentiometer and a control knob on it.

The reason I didn't use it is that it is the same solution I have tried when burning two potentiometers with my power supply, the difference was only that now the pot is soldered to something rather than me attaching the wires crudely to the ones I bought from Jaycar :lol:

Now I am sure the potentiometer solution is a good one, just didn;t work with the power supply I have, I guess. I even went back and bought a bigger potentiometer (1M?) and that one burned as well, so when I got my fan speed controller from ebay and saw that it had a potentiometer again it went straight into a drawer.

Maybe the problem is my power supply?
It's one of those small ones, a plug in the wall and a thin wire I have cut the plug off. (not like a laptop one that has a big box between the power socket and the lead that goes to the pc, so it doesn't look all that powerful but I have of course forgot what the output rating said)


In my defense, I did print out the parts list and drawing from page 28 as suggested by Crozdog as well. Went to Jaycar and just hoped I could get this mythical PWM thing to work. After trying to help me find something, the guy working there didn';t think buying parts and trying to solder something was an option either, heheh.

thanks
Bjorn

 

[Banshee]

Bjornj

Be aware that the unit I posted must not exced 1.5amp input. I think that is equal to 1500mA.

I use a 500mA 12v power pack with a 500k potentiometer. Mine has not burnt out yet, built up only one starter so far. I am aware and been advised that pots are not designed to regulate voltage. That is what the Lm317 is designed for. If and when my pot fails me I will be buying one of the units I posted prior.
When your unit arrives and you get it wired up and running, I would like to get you feedback/response on the unit please.
Cheers.

 

[BjornJ]

Banshee, happy to give feedback of course.
But again all this talk of wiring this and that up, will see if that happens

Whenever there is talk of tools I think I should ask Barls, so maybe I will have to ask for his advice on this thing as well, hehe.

Bjorn

 

[brando]

Circuit is from LC's post a while back, The fan wont spin unless the pot is up high, then you have to turn it down. The max speed of the fan is lower than when connected to the fan straight from the 12 V power source. I guess this is the reason why?

Will grab a 5K pot and wire it up as in diagram.

I did have a fan controller but its a 4 terminal one and too large for what I need.

Cheers

I used LC's circuit, but Jaycar didn't have a 5k pot so I bought a 10k pot, and doubled the 680ohm to 1.3k. Hope that is right - working ok so far, but early days.

 

[BjornJ]

checked my power supply now.

it says 13 Volts, 300 mA so hopefully that will be ok.

 

[barls]

bjorn, ill get it off you and have a look if you want.
btw just sent off the email we were talking about the other day.

 

[BjornJ]

Barls, let's have a look at it if you have time when I get the part from China.

Awesome on the other stuff, would be fun if we could pull it off as a small project

 

[LethalCorpse]

brando, you've got it spot on - 10k pot with 1k3 fixed will work just as well, should give you 1.25V - 10.9V


Bjorn, you've got the wrong end of the stick, again. Computer fan speed controllers are not (or at least, bloody well shouldn't be) simple potentiometers. Every one I've ever seen has a small circuit board attached to the pot, which contains a small linear regulator or PWM circuit. The pot is just there for adjustment.

 

[matho]

i havent read thru the 33 pages and if pwm circuit has be dicussed before please forgive me.
i have just finnnished putting this circuit together and it works very well,I havent tried it with a stir bar in a flask yet but will soon



the parts cost about $10 from jaycar, i used a IRFZ40N instead of the stated mosfet because of availablity.

cheers matho