openinverter forum

I have a PM300CLA060 3ph power brick here - one of many from a collection of Vectrix motor controller boards each in varying states of 'knackered'.

I'm trying to test one of the bricks on the bench here to see if there's any life in it - now, for context, this one is from an MC which died a fiery death owing to a well documented fault in the early gen motor connection posts - so it is entirely possible that this brick is 100% knackered and I'm not, in fact, doing anything stupid. Nevertheless, I find it's generally a good idea to check.

Brick has a 19 pin control arrangement (3x4-pin high side control, 1x7pin low side).

To test the high side I have PSU set at 15V providing Vd across power and return and I'm testing each phase in isolation. For input triggering I'm just tipping the input to the poles. I have a 14.4V battery '+' on the 'P' terminal with return from the phase to the battery through a small motor.

To test low side, battery '-' goes to N, and battery '+' goes to my load motor and return is, ostensibly, through the phase on the brick. Control shifts to the 7-pin arrangement for the low side (common VD bus for all 3 phases) and the same pole tipping method is employed.

Neither side produces any result on any phase - hence the thread. If I was getting even a partial response I'd be satisfied that the method is sound, but given no response from anything I figured I'd best check.

Only thing I haven't done is check the fault outputs. There's one pin in this regard for each group, however I can't see anything in the datasheet which suggests than a fault (all of which are thermally activated and self resetting) impedes function.

Cheers!

Extremetaz wrote: ↑Fri Apr 23, 2021 9:52 pm
Only thing I haven't done is check the fault outputs. There's one pin in this regard for each group, however I can't see anything in the datasheet which suggests than a fault (all of which are thermally activated and self resetting) impedes function.

Cheers!

Nice brick! Very complete.
You have application on page 6.
"Use 4 isolated control power supplies (Vd)"
Signals are active low!
Can you scope the Fo output in normal operation? Is it floating or is it open to GND?
I think you can apply for example 15V from your Vd supply and provide opto with pullup. When Fault would activate it gets pulled down. Then on the other side you use opto transistor with pullup on the output and connect one NPN transistor which will pull MPROT line to GND when opto releases.
EDIT: Deadtime seems to be very low, 0.8us + your choice of switching optos.

Yeah, they're a fine piece of kit alright and would be great if I can verify that any of them are still good.

Yes, Isolated power to each high side phase, common rail on the low side; and yes, pull down to gate.
Agreed, FO is an open collector arrangement, haven't probed them but can easily put a Scope/LED to them to find out.

Haven't gone as far as building the application circuit, have literally just been connecting the input pin in each instance to each pole of VD (I'm testing each stage in isolation) - if there's an actual need for the opto circuit for the sake of a bench test, I haven't twigged it; and as they're a voltage driven device I've assumed no requirement for current limiting on the gate.

If either of those assumptions are inaccurate for any reason I'd be keen to know - if they aren't, then this particular brick seems to be crock'd so I'll just move on to another one.

Method was the problem - one brick so far definitely blown, but one testing perfectly. Have 3 more to recover from the boards they're on now.

Missing ingredient was the fault outputs which I'd been ignoring - if they don't have VD on them, then the related stage won't function reliably.