Bleeder Resistor.

[leadfootdriver]

'Anyone use something like a a 10W-220k wire wound for the Express bleeder?

I think I'll do something like this instead of doing a series deal.

[Gaz]

Why 10W?

[leadfootdriver]

Because 2-3-watt, 100k resistors = a 1-200k, 6 watt. The next common rating is a 10 watt.

If you can find a 6 watt, well then great. But it's not hurting a thing by going to a 10 watt.

I'm thinking KF just put in what he had laying around.

[Gaz]

Ok, I've got your logic. If you're interested, here's how to calculate how much power the bleeder will dissipate using Ohm's Law.

P= E2 / R

With Express values:

415vdc * 415vdc / 200k = .86W

You could go with one 2W for a reasonable safety margin. And although it's never bad to overrate components in the power supply, a 10 watter there is a little needless. 5W would be a good copromise, and save a little space.

[pablogt]

Or use this calculator http://www.the12volt.com/ohm/ohmslawcalculators.asp if you are lazy like me.

Pablo

[leadfootdriver]

Ok, I've got your logic. If you're interested, here's how to calculate how much power the bleeder will dissipate using Ohm's Law.

P= E2 / R

With Express values:

415vdc * 415vdc / 200k = .86W

You could go with one 2W for a reasonable safety margin. And although it's never bad to overrate components in the power supply, a 10 watter there is a little needless. 5W would be a good copromise, and save a little space.

I guess a 10w would be a little big...

How would it affect noise tho? It seems like grounding out the power supply would be a source for hum. Maybe a wire wound for this position would be best, no?