We received some stepper drivers on Monday – TB6600 based boards. These are 4A bipolar stepper drivers and are very cheap on ebay (£7 per motor). The downside is this sort of ebay driver is often a bit rubbish – this thread documents some of the bad things. The worst problems:
- powering down the logic side of the circuit but leaving the motor supply connected = burnt out driver.
- output current is often less than it should be (due to shut-down circuitry)
- circuit uses the a pin on the TB6600 to provide 5V to the supporting circuitry – but that pin is for a decoupling capacitor – it isn’t meant to provide power to anything else
So last night we decided to find out exactly what might be wrong with our drivers by tracing the schematic. This way we can work out a method to avoid the worst problems and (hopefully) get reasonable performance out of our motors!
Here’s the schematic we came up with for our particular TB6600 driver – YMMV…
If you’re reading this because you’re interested in building your own robot, and you don’t fancy mucking about with reverse engineering cheap drivers from ebay, do yourself a favour and build/buy decent drivers – e.g.
- Buy nice drivers:
- DIY nice drivers: