View Full Version : PWM brake vs Linear brake

Crash & Burn
05-06-2006, 06:34 AM
I would like to know whether a brake based on Pulse Width Modulation with a Mosfet transistor is a better brake then just a conventional high wattage wirewound pot?
And how do you generate the pulse? Which electronic parts are needed and maybe someone has electronic scheme.

Would there be a difference in full brake performance between just shortcutting the track wire with (-), the conventional method so to speak, or doing this with a Mosfet with the PWM princicple?
In my simple perception full brake is fullbrake but maybe there's more to it.

05-06-2006, 04:32 PM
And possibly a bit more robust.

The high wattage pro-brake pots are EXPENSIVE. If you get one through a small order catalog distributor instead of Difalco or Koford, you'll still pay about $30.

On the other hand, a power mosfet will run you a couple of bucks. The PWM and protection circuitry will run the cost up, but not as much as the pro pot.

There won't be any difference in braking performance...the on resistance of a MOSFET is negligible.


05-08-2006, 09:12 AM
I've been using it for years on everything from Fly cars to 1/24 euros. Its useful to keep the mosfet driver powered for a bit after track power is removed. Don't ask me how I know.

Crash & Burn
05-08-2006, 09:59 AM
THX for all the answers. Anyone have a small mosfet brake scheme for me?


05-08-2006, 10:04 AM
OR you can just use a switch and a few diodes as the Omni/Cidex showed us.
switch position:
1- full brakes/no resistance
2- one diode/just a bit of brakes/most often used
3- two diodes in series/a little less brakes
4- three diodes in series/a little less brake
5- add more diodes in series/and so on and so on
6- open switch/no brakes at all