I've got a strange (to me) problem with some interesting scope traces:
The circuit is two separate 3023 optoisolators driving two separate triacs, each one powering a large 3-phase contactor. One contactor is engaging fine. The other one is rattling badly because it isn't getting full power to pull in.
Each circuit looks like this:
The top photo shows trace from the good triac circuit, working fine. Bottom photo shows the bad one. It looks like the triac is dropping out right after hitting peak positive voltage.
- What's going on?
- More importantly, will replacing the triac fix this? A new board is going to cost me $480.
Thanks for any help. I'm a first time poster who is in over his head on a repair - really more of a mechanical guy than an electrical expert. (I'd be happy to trade mechanical advice!)
The circuit is two separate 3023 optoisolators driving two separate triacs, each one powering a large 3-phase contactor. One contactor is engaging fine. The other one is rattling badly because it isn't getting full power to pull in.
Each circuit looks like this:
The top photo shows trace from the good triac circuit, working fine. Bottom photo shows the bad one. It looks like the triac is dropping out right after hitting peak positive voltage.
- What's going on?
- More importantly, will replacing the triac fix this? A new board is going to cost me $480.
Thanks for any help. I'm a first time poster who is in over his head on a repair - really more of a mechanical guy than an electrical expert. (I'd be happy to trade mechanical advice!)