Help needed - MOSFET driven by PWM

[Acetronics2]

Hi, Bcd

Have a look to this :

http://www.picbasic.co.uk/forum/atta...7&d=1202029322

you'll find some Igbt ( quite as Mosfets for drive ) simple driving ... note the Optocoupler is not compulsory !

Alain

[JD123]

I've used the IRF540's for years in high amp motor drives and 5 volt gate drive. You are right about the effects of not saturating the gates. I got around it by using one 540 for every 10 amps (peak) of draw. I'd typicaly use 8 for an 80 amp draw. I don't think you'll see much, if any probelms using 5v gate drive and 5 amp draws. The 540's are going to get warm running at 5 amps and fast chop rates.

If you have a source available at 10v or more, I'd do something like was shown above, though I'd just transistor buffer (darlington best) the drive. I don't think opto isolation will be needed for what you're doing.

Acetronics, you ever make ESC's for brushed motors? The description above ran an Astro FAI 035 with a 9x6 direct-drive on 7 cells :0 That was power... back in them days!

[Acetronics2]

Hi,

as Gary made me think a while ...

it would be easy to make a simple diode-pump voltage doubler with the OSCout as a clock source ...

in the SEARCH ... I remember something was posted on this topic ... sent to Trent Jackson ...

Alain

[JD123]

Yep, I was thinking of that when I posted and forgot to get it in the post.

[Acetronics2]

BINGO !!!

http://www.picbasic.co.uk/forum/atta...8&d=1190450941

Alain

Hi, Gary ... Still have a wonderful ESC with a LM 358, LM339 and 4 IRFZ's 30 !!! ...