Hello Guest it is November 15, 2019, 05:34:22 PM

Author Topic: ALLEN BRADLEY 2090-UCSR-A300  (Read 1297 times)

0 Members and 1 Guest are viewing this topic.

Re: ALLEN BRADLEY 2090-UCSR-A300
« Reply #10 on: March 09, 2018, 01:27:33 PM »
Hi,
added a couple of diodes, D2 prevents the opto LED of high reverse bias if ACline disappears but DCLink stays up.
D3 prevents massive forward current in the event that ACline is still up when DCLink is down or shorted low.

Craig
My wife left with my best friend...
     and I miss him!

Offline fast89

*
  •  137 137
    • View Profile
Re: ALLEN BRADLEY 2090-UCSR-A300
« Reply #11 on: March 09, 2018, 04:10:32 PM »
The big round resistor has 306k ohms. The larger igbt in the lower right corner has 11.5 ohms from center to left leg and .5 ohms center to right leg.
Re: ALLEN BRADLEY 2090-UCSR-A300
« Reply #12 on: March 09, 2018, 04:30:00 PM »
Hi,
don't think those sound right.

The big (main) braking resistor should be about 36 Ohms.

Resistance measurements are not really effective with a MOSFET/IGBT.
You need to use  diode check on your multimeter, positive drain (center) negative source (right) should be close to open circuit.
Negative  drain (center) to positive source (right) should be the MOSFET body diode, about 450mV.

Would expect drain (center) to gate (left) to be close to open circuit.

Craig
My wife left with my best friend...
     and I miss him!

Offline fast89

*
  •  137 137
    • View Profile
Re: ALLEN BRADLEY 2090-UCSR-A300
« Reply #13 on: March 09, 2018, 05:01:10 PM »
I just opened up the second one i bought. No wonder it doesn't work, its completely burnt inside. Just can't have nice things.
Re: ALLEN BRADLEY 2090-UCSR-A300
« Reply #14 on: March 09, 2018, 05:04:15 PM »
Hi,
yeah, these things live at the 'sharp end', if anything is going to go bang its these.

Craig
My wife left with my best friend...
     and I miss him!