Re: [CAD_CAM_EDM_DRO] Chopper max voltage?

Ay, that would sound right, I never actually tried them at the higher
voltage without the current fall back. The L298 costs $15 NZ a shot here,
so I wasn't all that prepared to experiment with them when I wasn't going to
produce more than five or six of the boards for myself...

re: heatsinks for general info, mine is three bits of 1/16th alloy bolted
together and spread out like a "fan". They are 2*3 inches (*3) for each
driver, and there is a 80mm 12V PC fan blowing through the "valleys" on the
heatsink, and they still get quite warm to the touch. Where the plates are
in contact with each other, and where they press up against the driver
heatsink tab I've used silicone heat conduction paste. Also the heatsink is
mechanically mounted to the PCB with alloys spacers to reduce mechanical
stress on the driver legs etc.

Had a look at the web site, the new board looks quite tidy, hope it does
well for you...

Cheers, Chris.

* Design engineer, Assembly worker, Cleaner.
* Ohmark Electronics. PO Box 5302, Christchurch, New Zealand.
* http://www.ohmark.co.nz

----- Original Message -----
> Without automatic reduced current the l298 doesn't last very long at 36VDC
> @2A. even with a massive heatsink and fan. I changed the design to use
> automatic reduced current and they seem to hold up very well. My new 3axis
> 2A board has this feature. I recommend that beginners stay under 18V
because
> of their propensity to use an inadequate heatsink and or fans above this
> voltage.
> Dan