Coolmaster

[vlbaby]

Ok built a second unit and it does the same as the first. Starting to think they're a peice of crap.

I got to watch it do its thing a couple of times today and they both flicker etc even with nothing plugged in so i assume this would rule out the freezer being the problem.

I did make a few small additions to the second unit so i can switch it between heat and cool option and also read set and fridge temps(voltage) via an rca plug that goes to my DMM.

Oh well they do at least work

Richard :angry:

[post="105064"][/post]​

you get some major points for persistance recharge. Seems strange that your still having probs even with no load connected. How do you know it is flickering with no load connected?
Is it possible that your 12V supply your using is the cause? Maybe you should try it with a battery supply to see what the result is.

VL.

 

[recharge]

Ok built a second unit and it does the same as the first. Starting to think they're a peice of crap.

I got to watch it do its thing a couple of times today and they both flicker etc even with nothing plugged in so i assume this would rule out the freezer being the problem.

I did make a few small additions to the second unit so i can switch it between heat and cool option and also read set and fridge temps(voltage) via an rca plug that goes to my DMM.

Oh well they do at least work

Richard :angry:

[post="105064"][/post]​

you get some major points for persistance recharge. Seems strange that your still having probs even with no load connected. How do you know it is flickering with no load connected?
Is it possible that your 12V supply your using is the cause? Maybe you should try it with a battery supply to see what the result is.

VL.

[post="105206"][/post]​

It has a red led which shows when it is on.
Did have thoughts about power supply today may try another.

Cheers
Richard

 

[muga]

I use these in my chest freezer and two fermenting fridges and don't have any problem, just made it like the kit said and they work fine.

 

[recharge]

I use these in my chest freezer and two fermenting fridges and don't have any problem, just made it like the kit said and they work fine.

[post="105209"][/post]​

But have you watched and or listened as they turn on?
As i mentioned earlier mine work but click in and out for a while before finally starting freezer.

 

[Screwtop]

Muga, would seriously be looking at the 12Vdc supply. Not the voltage as this is regulated internally but the waveshape. Try a car battery (nice smooth 12V), see what happens.

Cheers

 

[recharge]

any chance a car battery would burn one out??

 

[stephen]

any chance a car battery would burn one out??

[post="105383"][/post]​

Recharge

The simple answer is no. A fully charged car battery is actually 14.4 vdc which, if memory serves me correctly, is within the input voltage range of the voltage reg - REG1 7809. Diode D1, 1N4004 is quite a robust bit of kit - 400v reverse polarity and can handle 1 amp so wont be a problem: These are often used in high voltage power supplies (200-300 v) for that very reason.

If you are still blowing these little babies up then I would look at the TRIAC1, BT 137F. These are rated at 8 amps. The switch on current of the compressor in your fridge/freezer will momentarily exceed this rating - normally this should not be a problem as the current spike is too short (time wise) to do any damage. If you have an old fridge or freezer These may take a little longer to start up and the current spike is long enough to do some roasting of TRIACs. If this the case you may want to substitute it with a higher rated triac - SC151D. This little beauty is rated at 15 amps! If you do substitute then make sure you check the pin configuration and the case design. These may not conveniently replace the existing Triac: eg. The mounting tab of the original Triac is not connected to any of the pins so this makes it simple to mount to a heatsink. The replacement I have suggested appears to have the mounting tab connected to one of the pins so should be isolated (electrically) from the heatsink. If in doubt or not sure what to do -

DON'T TOUCH A THING - THIS IS THE 240V SIDE OF THE CIRCUIT AND THESE VOLTAGES CAN CAUSE DEATH AND/OR SEVERE DAMAGE IF NOT TREATED PROPERLY!!!

 

[recharge]

any chance a car battery would burn one out??

[post="105383"][/post]​

Recharge

The simple answer is no. A fully charged car battery is actually 14.4 vdc which, if memory serves me correctly, is within the input voltage range of the voltage reg - REG1 7809. Diode D1, 1N4004 is quite a robust bit of kit - 400v reverse polarity and can handle 1 amp so wont be a problem: These are often used in high voltage power supplies (200-300 v) for that very reason.

If you are still blowing these little babies up then I would look at the TRIAC1, BT 137F. These are rated at 8 amps. The switch on current of the compressor in your fridge/freezer will momentarily exceed this rating - normally this should not be a problem as the current spike is too short (time wise) to do any damage. If you have an old fridge or freezer These may take a little longer to start up and the current spike is long enough to do some roasting of TRIACs. If this the case you may want to substitute it with a higher rated triac - SC151D. This little beauty is rated at 15 amps! If you do substitute then make sure you check the pin configuration and the case design. These may not conveniently replace the existing Triac: eg. The mounting tab of the original Triac is not connected to any of the pins so this makes it simple to mount to a heatsink. The replacement I have suggested appears to have the mounting tab connected to one of the pins so should be isolated (electrically) from the heatsink. If in doubt or not sure what to do -

DON'T TOUCH A THING - THIS IS THE 240V SIDE OF THE CIRCUIT AND THESE VOLTAGES CAN CAUSE DEATH AND/OR SEVERE DAMAGE IF NOT TREATED PROPERLY!!!

[post="105387"][/post]​

Stephen i havent blown any up, they both work but are having the same problems as in original post. They both do it even with freezer unplugged. My major concern is long term effect this jittery(for want of a better description)starting will have on freezer. Have decided anyway to go for a Tobins type thermostat as discussed in other threads. And use jaycar ones for running fans for aircooling ales etc.

Cheers
:beer:
Richard

 

[stephen]

any chance a car battery would burn one out??

[post="105383"][/post]​

Recharge

The simple answer is no. A fully charged car battery is actually 14.4 vdc which, if memory serves me correctly, is within the input voltage range of the voltage reg - REG1 7809. Diode D1, 1N4004 is quite a robust bit of kit - 400v reverse polarity and can handle 1 amp so wont be a problem: These are often used in high voltage power supplies (200-300 v) for that very reason.

If you are still blowing these little babies up then I would look at the TRIAC1, BT 137F. These are rated at 8 amps. The switch on current of the compressor in your fridge/freezer will momentarily exceed this rating - normally this should not be a problem as the current spike is too short (time wise) to do any damage. If you have an old fridge or freezer These may take a little longer to start up and the current spike is long enough to do some roasting of TRIACs. If this the case you may want to substitute it with a higher rated triac - SC151D. This little beauty is rated at 15 amps! If you do substitute then make sure you check the pin configuration and the case design. These may not conveniently replace the existing Triac: eg. The mounting tab of the original Triac is not connected to any of the pins so this makes it simple to mount to a heatsink. The replacement I have suggested appears to have the mounting tab connected to one of the pins so should be isolated (electrically) from the heatsink. If in doubt or not sure what to do -

DON'T TOUCH A THING - THIS IS THE 240V SIDE OF THE CIRCUIT AND THESE VOLTAGES CAN CAUSE DEATH AND/OR SEVERE DAMAGE IF NOT TREATED PROPERLY!!!

[post="105387"][/post]​

Stephen i havent blown any up, they both work but are having the same problems as in original post. They both do it even with freezer unplugged. My major concern is long term effect this jittery(for want of a better description)starting will have on freezer. Have decided anyway to go for a Tobins type thermostat as discussed in other threads. And use jaycar ones for running fans for aircooling ales etc.

Cheers
:beer:
Richard

[post="105389"][/post]​

Recharge

I guess I'll have to wait until I pruchase one and have a play before I can provide a definitive answer. So far all my theorising has been based soley on the circuit diagram and a bit of reverse engineering.

Until I buy my Coolmaster and tinker with it I can't provode any more answers.

Steve

 

[recharge]

cheers stephen.
They call it a tempmaster now, same part number though.

 

[stephen]

cheers stephen.
They call it a tempmaster now, same part number though.

[post="105392"][/post]​

Always moving the goslposts!!! Damn it!

 

[recharge]

Fingers crossed i can put this thread to bed now.

Changed power supply to 9vAC 1000mA today and seems to have fixed problem, i watched it switch on cleanly 3 times today.

Heres hoping.

Cheers all
:beer:

Richard

 

[Simon W]

Well there you go. Well done Richard!

I had considered the power supply, but decided the circuit had ample supply filtering with the two stiffening caps.

Now I'm sorry I didn't mention it.
Call me nasty names if you want

 

[recharge]

Would never call you nasty names Simon, your input was valued and whilst i dont understand it all i learned a few things along the way. Thank you and all others who replied

Cheers

Richard

 

[recharge]

Thought i'd post an update.

OK here's the deal - two different controllers, two different chest freezers sometimes they switch on cleanly sometimes they dont.
I think the 9v ac 1 amp power supply is better than the 12v dc 300mA one i was using previously.
I spoke to a fridge shop who says the prob with a lot of digital conrollers is they dont give the freezer enough off time, this sorta fits my probs.

So my verdict = dont waste your money on this controller for a chest freezer (just my opinion based on my experience)
Bought two Tobins during the week from All Controls (thanks Chilla) perfect!!

They wont go to waste as i'll now use them to drive pumps for my future jacketed fermenters.

Many thanks again to all who tried to help.

Cheers :beer:

Richard

 

[Tony M]

There is no reason I know to have your fridge operating in a narrow +or- 0.5C band if you only wish to hold the fermentor at 12C. The thermal mass of the beer is so great that the air temp around it could cycle several degrees without any measurable temperature fluctuation in the fermentor. The same applies to keg storage.
If you set the hysterisis wide, the compressor will be much happier as it will get a decent run.

 

[recharge]

There is no reason I know to have your fridge operating in a narrow +or- 0.5C band if you only wish to hold the fermentor at 12C. The thermal mass of the beer is so great that the air temp around it could cycle several degrees without any measurable temperature fluctuation in the fermentor. The same applies to keg storage.
If you set the hysterisis wide, the compressor will be much happier as it will get a decent run.

[post="114289"][/post]​

I agree tony but although i can solder and built the kit, i believe the hysterisis is preset and i wouldnt know how to work out values to change it.

Cheers

Richard

 

[thunderleg]

I built one of these Tempmaster units. It was working fine and I was really happy with it for about a month. Then it just crapped out. The fridge got really cold and was running even when the LED on the unit was extinguished. A few probes with the multi-meter (AC unplugged) shows that the DC side is working fine, but the AC side just wants to power up the fridge all the time. :angry:

 

[vlbaby]

I built one of these Tempmaster units. It was working fine and I was really happy with it for about a month. Then it just crapped out. The fridge got really cold and was running even when the LED on the unit was extinguished. A few probes with the multi-meter (AC unplugged) shows that the DC side is working fine, but the AC side just wants to power up the fridge all the time. :angry:

[post="115237"][/post]​

Sounds like you've blown up the triac in the circuit. Dickie smith will sell you a new one.
vl.

 

[2es]

I blew several triacs solved problem with extra fan across fridge lead.Had false operation when working in shed grinding etc so fitted 4700mfd capacitor across sensor to flatten out spikes.Seams to work now.