The PSU on my lathe is something I made myself. On the input side are two SSRs, one for power on/off and the other switches-out a soft-start resistor. There is also s discharge capacitor that is switched in when the main input SSR is switched off.
Today things went a bit strange, blowing the breaker and then the discharge resistor. This was with the PSU powered up, but not turned on. It turns out that I have an unanticipated failure mode, if both input SSRs fail closed-circuit. I have tested the SSRs on the bench, running a light bulb, and they both light the bulb with nothing connected to the control terminals (And with the control terminals shorted together). So, I am wondering if there is a problem running a rectifier input with SSRs. I found something in an Omron document suggesting that turn-off might be unreliable, but that doesn't seem to be the issue here, the relays are now incapable of turning off a (filament) light bulb. Did I get unlucky, or are SSRs a bad choice for this application? -- atp "A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." — George Fitch, Atlanta Constitution Newspaper, 1916 ------------------------------------------------------------------------------ Find and fix application performance issues faster with Applications Manager Applications Manager provides deep performance insights into multiple tiers of your business applications. It resolves application problems quickly and reduces your MTTR. Get your free trial! https://ad.doubleclick.net/ddm/clk/302982198;130105516;z _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
