Very similar types are available from several manufacturers.
It is based on a pair of BTS7960 half-bridges from Infineon, with a cmos logic chip included to give them a clean drive from external circuits – like Arduinos.
Current capacity is pretty good – >30A at several tens of volts as I remember, at up to over 20kHz.
Automatic anti-shoot-through circuitry is included on the chips, making these easy to drive as no multi-phase waveform is required.
Some come without a heatsink, and most come with one – although the jury is out on whether they are large enough to handle anything like full power. BTW, mine came with no heat transfer paste between board and heatsink – worth checking.
Upside-down to show the feet – and yes, I only had two bolts the right length.
Anyway, apart from heatsink-down, which is not great for heat dissipation, they don’t have a natural way of standing up without assistance so I knocked up a stand design and printed one in PETg – a material that resists heat more than the standard PLA plastic, and is less brittle.
Once again, this was not a case of finding something for the printer to do, but realising that the printer was the simplest and quickest way of getting the job done.
The design lifts the heatsink up a bit for better airflow and could easily be altered to accommodate a fan. It includes a small cover (not visible) for the back of the header pins, leaving nothing low down that could be shorted by stray wires on the bench, and a hole to screw it down through if needed.
I did run a tap through the plastic to cut threads, but I suspect screwing the bolts straight in would ave worked too – PETg is unlikely to crack unless heartily abused.
If I had a little more time, I would work out how to stick it on Thingiverse for others to use.
- CAD software: DesignSpark Mechanical
- Filament: filamentive recycled PETg
- Printer: Creality Ender 2
BTW2, if anyone has this printer, I have a nice design for large print bed adjustment knobs that don’t foul the stepper motor (two large and one small is the usual work-around), and also offer calibrated bed adjustment.