Tiny PWM controller for TEC.. Need some.

[NotSoCoolJ]

That pretty much clears it up. I didn't think I was following your directions properly. I see what you mean now about the zener diode. When it reaches break down voltage It passes through and the cap takes over. Thats a nifty little diode regulator. Now about the toroid. Is there a specific inductance figure I should look for? Will any old one off a board or out of a PS work?

Thinking about the toroid I Have found about 6 various types around the house. I would think that by your high current notation I should go with the the one that has the fewest turns of the largest wire. The toroid that I have in mind has 5 turns of large diameter wire and was located near the ATX power input on a dead main board. I don't have a circuit set up for inductance measurement. However, that 4700 micro farad cap is quite large so I would think it's not of great importance.

Tomorrow, I will order the MIC502. I will be getting 10 so I have a few extras. If anyone wants one or two I'll gladly ship them out to you. Right now, I plan on useing 4 and I'd like a few extras. So I will have 4 available. Just rock me off a PM if you want one. Uncle Jimbo I will send you one of these controllers if you want one. Just let me know. Or I can just send you the parts. Too me building these things is half the fun.

Woops.. Before I buy these things I was wondering about the pin out in your diagram. In the data sheet it appears to be opposite.

[NotSoCoolJ]

Well never mind on that. It appears that the mic5021 and MIC5020 are different chips all together.
The actual part number is MIC502BN or MIC502YN for the lead free variety.

Ok so after some more digging I found the right chip. from a US supplier.

I will edit the previous Link location for the US supplier to the correct one.

[Uncle Jimbo]

That pretty much clears it up. I didn't think I was following your directions properly. I see what you mean now about the zener diode. When it reaches break down voltage It passes through and the cap takes over. Thats a nifty little diode regulator. Now about the toroid. Is there a specific inductance figure I should look for? Will any old one off a board or out of a PS work?

Thinking about the toroid I Have found about 6 various types around the house. I would think that by your high current notation I should go with the the one that has the fewest turns of the largest wire. The toroid that I have in mind has 5 turns of large diameter wire and was located near the ATX power input on a dead main board. I don't have a circuit set up for inductance measurement. However, that 4700 micro farad cap is quite large so I would think it's not of great importance.

Tomorrow, I will order the MIC502. I will be getting 10 so I have a few extras. If anyone wants one or two I'll gladly ship them out to you. Right now, I plan on useing 4 and I'd like a few extras. So I will have 4 available. Just rock me off a PM if you want one. Uncle Jimbo I will send you one of these controllers if you want one. Just let me know. Or I can just send you the parts. Too me building these things is half the fun.

Woops.. Before I buy these things I was wondering about the pin out in your diagram. In the data sheet it appears to be opposite.

That is exactly the kind of toroid I had in mind. It doesn't matter much what value it is - we are just using it to smooth out the power.

I would love to have one of the finished units - not only because it would be cool, but also that way if something goes wrong I have the identical unit to debug.

Good luck with it.