Good news for RepRap makers, Zach writes –
I’ve finished two new versions of the boards for the Arduino electronics. These are incremental improvements that offer cool stuff like more blinky LEDs, minor fixes, and such. Full build pix, tester code, and everything you need to know to get started with these boards.
The DC Motor Driver board will control 2 small DC motors (or you could drive a small stepper if you wanted).
The PWM Driver board will control 3 channels of PWM at up to 5A each (theoretically) This is used for things like fans, heaters, etc that just need to be turned on/off.
The files are released on SourceForge, the boards are for sale in the RRRF store, and everything should be fully documented.
RepRap PWM Driver v1.1 / DC motor driver v1.1 released – Link.
4 thoughts on “RepRap PWM Driver v1.1 / DC motor driver v1.1 released”
Awesome, perfect timing. I just started an Arduino based project that needs to control two motors. Ordering one of these right away.
TIP120 is a darlington, which means it has good Hfe but bad Vce(sat). Figure maybe 1.5v at 5A, and 5A*1.5V=7.5W. From the photos it looks like there is no room for heat sinks. 7.5W is well in excess of the thermal rating of a bare TO-220. The smart money is on this thing melting if you ever try 5A.
Also PWM through darlingtons is kinda sketchy — they aren’t very happy at more than a few khz. You’d have to either use really slow pwm or put an rc filter on the base and run in linear mode.
You really want to be using n-mosfets here.
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