Help with PSU (Temp control fan, load bank, & PWM circuit)

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No, that makes sense, I was wondering if that was the case. OK, so I will just stick with one circuit for each unit...probably safest set up like that anyway.
 
Just got an text from my wife...I got a package from mouser today, so I will be building the temp control circuit for the dummy load tonight fun stuff!
 
Yes, thats the one. There are better ones but that one is the easiest I have found to learn. You want to make the single circuit as small as you can then put multiples of the circuit on a single layout - That will get you the best price. It's only to get an idea of the cost.

Anyway they want $90 for 2 boards of 19 sq. in. each. That would probably be ~$3 each for about 32 little boards.
 
Is this is just for the printed board, then I still need to buy and assemble the components? I still think that would be worth it as it would save time and look better.
 
Yes just for the board. You would have to cut them to size, then stuff and solder them. The nice thing is no wiring errors, fast assembly and a professional look.

I think there are cheaper places. There may be a topic here about it. In that case you would probably want to use Eagle software because it outputs a file that everyone uses. It is very good but more difficult to learn. There are some Eagle pros here. Maybe one of them would layout a board for you or you can learn it.
 
hm, the price of the Egle software alone almost makes it worth it stick with expressPCB since they have free software...I guess it all depends on how many of these I sell.
 

What about this one:
https://www.digikey.com/product-detail/en/TLV271IP/296-34453-5-ND/1677964

I couldn't find any of the TS924 with only one circuit, they all had 4.
 
OK, so I was doing a little experimenting with the dummy load/PSU and tripped the over current protection in the PSU (tripped at 55amps), and realized maybe I should not do that in the future. I hope I didn't break the dummy load too bad, the PSU is fine, but the dummy load is a permenant short circuit now between the positive and negative at the leads where I plug it into the PSU. I checked for continuity with my voltmeter. Do you think I just blew the TVS and once I replace that all will be well? I've tripped the overcurrent protection in the PSU with the dummy load before without issue, in fact I tripped it twice tonight and only on the third time it caused problems. If you're wondering why I kept intentionally tripping the overcurrent protection, I was trying to verify what load sets it off. The first time I tried it, it went all the way to 62 amps before it tripped but I think I turned the current up too fast, so then I tried turning it up slowly and it tripped at 55, I was trying it a third time to veryfy and then when I tried turning it back on the PSU would not power up, come to find out its because it was sensing the short circuit. At first I thought I broke the PSU.
 
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Hmm. I would think maybe the TVS, but it is hard to say what the PSU does when it trips. I would just clip it out and measure again.
 
Yep, that did it. Just replaced the TVS and all is well in dummy load land. I still wonder why the TVS failed in the first place. I guess the PSU must have sent a jolt of over voltage through the dummy load when I tripped the over current protection in the PSU.

After I unsoldered the broken TVS, I noticed the plastic casing was cracked all the way around it, not sure if I did that when desoldering it or when it broke in the dummy load.
 
I've only blown one other one on a big motor controller. It just blew up. It gave its all to save 10 FETs.

Are the wires short between the supply and the load?
 
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Must just be the very high current. Looks like the TVS saved the bacon.
 
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