Hi
I’ve got a CRC Cap-bank, 4 x 18000 uF… before working on it I need to drain then, but I‘m not sure wether to put the resistor between - and + or a resistor each between +/- and 0 ?
I’ve got a CRC Cap-bank, 4 x 18000 uF… before working on it I need to drain then, but I‘m not sure wether to put the resistor between - and + or a resistor each between +/- and 0 ?
If it is a normal split rail supply with two caps on each rail you need to do each rail in turn. All depends on the how they are wired really. You can do rail to rail but the voltage seen by the resistor is doubled and resistor dissipation goes up by a factor of 4.
A single power resistor between + and - will do ok. Otherwise the usual single supply to ground is fine.
On the official schematic, there is a 2.2k resistor to ground from each supply, so they should self-discharge
without any intervention. Use caution, shock hazard. Don't short anything.
On the official schematic, there is a 2.2k resistor to ground from each supply, so they should self-discharge
without any intervention. Use caution, shock hazard. Don't short anything.
Another side benefit of having POS_OK and NEG_OK light emitting diodes. They tell you whether each rail is, or is not, discharged.
Thank you, @rayma ! I was made aware of the shock hazard when I built my previous little beast, all by ZM: several weeks after I had the PSU up and running, I wanted to fiddle with something and got a heartstopping zap when I glitched and shorted two contacts...
@Mark Johnson , thanks for the heads-up/hint. (just moments ago I read this in the LM317-thread … 🙂 ) — did you hear about my H9KPXG adventure? Like it veeery much, even with a switch!
I have to apologize for an inaccuracy: It is not a firstwatt-FirstWatt PSU, but one that meets its requirements, from mighty ZM... As we all know, he has a minimalist twist to certain things, thus, it's rather POS_ZAP and NEG_ZAP. But the boards come in very handy, so to say.
(And, as some of you probably know, I ... don't know very much, but I like it)
@Mark Johnson , thanks for the heads-up/hint. (just moments ago I read this in the LM317-thread … 🙂 ) — did you hear about my H9KPXG adventure? Like it veeery much, even with a switch!
I have to apologize for an inaccuracy: It is not a firstwatt-FirstWatt PSU, but one that meets its requirements, from mighty ZM... As we all know, he has a minimalist twist to certain things, thus, it's rather POS_ZAP and NEG_ZAP. But the boards come in very handy, so to say.
(And, as some of you probably know, I ... don't know very much, but I like it)