Hi!
I need some PWM controller, that can controll motor to run in booth direction, best would be when potmeter is in middle that motor stands, and when we changing potmeter to each side so motor speed up in each side.
I did allready do soemthing with H bridge but mosfet's died when I put load on it, I need smeting that could hand 10 or less A on 24V.
Thanks,
Marin
The H bridge is the correct approach. You need to figure out why things are failing.
Check the specs on the MOSFETs to see if they need external diodes or snubber circuits for inductive spike protection. Make sure the MOSFET drive is sufficient to turn them on quickly. Also, make sure you don't hook up the supply backwards.
-- Paul Hovnanian mailto:Paul@Hovnanian.com ------------------------------------------------------------------ IRS: We\'ve got what it takes to take what you\'ve got.
I did but they still fail, probably because opposite mosfet's get's some on gate because of inductance load.
This was going from LM324 OP amp, I also did try to add tranzistors, looks better but still same. What is you're advice about driving it?
Pick one that suits your needs.
-- Paul Hovnanian paul@hovnanian.com ----------------------------------------------------------------------- Have gnu, will travel.
I think none:
NO RESULTS FOUND.
:-)
"mtech" schreef in bericht news:g5tba3$jaa$ snipped-for-privacy@ss408.t-com.hr...
Just click one more on the Search button.
One other thing: You'll need to be sure that under no circumstances the high and the low FET on the same side of the bridge conduct at the same time. This causes a short that may fry the FETs in a very short time. Commercial bridge drivers usually has a protection build in.
petrus bitbyter
Right. If one knows what they are doing, one can incorporate this into their own design. OTOH, if someone needs me to push the 'Search' button for them, use a commecial part. ;-)
-- Paul Hovnanian mailto:Paul@Hovnanian.com ------------------------------------------------------------------ c (velocity of light in a vacuum) = 1.8x10^12 furlongs per fortnight
=3D1323
high
.ial
One thing to be aware of is that you can't drive your PWM to 100% if your high side drive is derived via a bootstrap cap on the output. ie IR2104 driver. The highside drive voltage will fall and your fet will start to go into it's linear region and get VERY hot before letting out the smoke :0) On an 8-bit pwm I've run up to 253 out of 255 (20KHz) no problem , so it's not as if you are loosing a lot of power because you can't run 100%
Cheers Rob
=3D1323
high
.ial
One thing to be aware of. If using a high side driver that uses a bootstrap cap from the output (ie: IR2104) you can't run your PWM to 100% If you do the output drive for the highside will fall away and your FET will start to be driven into it's linear region. Not a great idea if you want to keep the smoke inside!! I've run the PWM to 253 out of 255(8 bit) at 20Khz no problem. cheers Rob
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.