Self Running Micro TPU, with closed loop.

[Groundloop]

[EDIT] Deleted.

[hakware]

@Hakware,

Thanks for the info. I will see if I can find another FET that work. My IRF540 does not do a good job in this circuit.

Groundloop2003

well the IRF740 might not be the best FET either, I should be able to run more LED's that 3 according to everyone else's reports here. Let me know if you get any better results with any other FET styles. It seems the FET is a key ingredient in higher output on this design.

For reference:
IRF740 Specs http://www.alldatasheet.com/datasheet-pdf/pdf/67495/INTERSIL/IRF740.html hakwares fet
IRF540 Specs http://www.alldatasheet.com/datasheet-pdf/pdf/22392/STMICROELECTRONICS/IRF540.html groundloops fet
IRF510 Specs http://www.alldatasheet.com/datasheet-pdf/pdf/67483/INTERSIL/IRF510.html plengos fet
IRF840 Specs http://www.alldatasheet.com/datasheet-pdf/pdf/22404/STMICROELECTRONICS/IRF840.html Original TPU speced mosfet

Seems lower resistance should be key but the 540 shows lower internal resistance than the one that plengo is using.

[Groundloop]

[EDIT] Deleted.

[hakware]

@groundloop

I have some IRF840's I will try them next and see if higher internal resistance makes magic on a different unit.
I am also going to dig out some 1:1 audio transformers I have around here and see if they will work. maybe take some of the coil guesswork out of it
with a standard off the shelf part..

[sanmankl]

Attached is a drawing of my circuit as it is now.

Regards,
Groundloop2003

@ Groundloop2003,

What software do you use to draw the diagram. Looks good!

Cheers, sanmankl