[Xerxes]

Returned energy: Never post until the brain is fully saturated with caffeine; it wasn't and I wasn't thinking. The theoretical maximum returned voltage is twice the supply voltage, i.e. motor back EMF equal to supply voltage, '-' side of motor to 'on' top bridge MOSFET.

I think it's not that way. Drive acts as step-up converter during braking where motor acts as inductor. So voltage can be pumped up almost infinitely. During braking current direcition just reverses and motor EMF doesn't play any role.

Attach more mass to the 48VDC motor and try running the test again

[ftkalcevic]

Sorry for waking such an old thread.

I was wondering if anyone makes a board, or kit, or module that provides the power dumping features?

On my servo power supply, I built a board based on Mariss's design (from the gecko yahoo group) with a few different parts. It work fine for a couple of years, then one day, I turned the power on, and after about a minute, there was a big bang, and lots of smoke coming out of the enclosure. The power resistor and the pcb around the resistor were toasted.

If I can't find a ready made one, I'll try building another.

[sea13]

Hi Mariss,

Just a short (and maybe stupid) question of mine:what is the diode value in the Dump1 circuit?

Thanks,

Sebastian