Bleeder resistors will bleed the capacitors all the way down eventually. Some circuits will only bleed them down to a couple of volts, because of the forward bias voltage of the semiconductor devices in the circuit. Some circuits will bleed them all the way down because they have a resistive path to ground. You have to determine which situation your circuit has.
Leaving caps partially charged can be a bad thing if you're going to be switching stuff around in a circuit. People that swap op amps have to be especially vigilant of this.
Leaving caps partially charged can be a bad thing if you're going to be switching stuff around in a circuit. People that swap op amps have to be especially vigilant of this.
> The effect of adding a bleeder
Dumb question. If you have a Speaker Relay, why not use the flip-side of that to bleed the main caps?
I've never seen it proposed.
Obviously it has no effect on ripple you hear, because it is only bleeding when the speakers are mute. It also avoids prolonged heat in bleed resistor.
Dumb question. If you have a Speaker Relay, why not use the flip-side of that to bleed the main caps?
I've never seen it proposed.
Obviously it has no effect on ripple you hear, because it is only bleeding when the speakers are mute. It also avoids prolonged heat in bleed resistor.
I proposed it a long time ago.
The bleeder is attached through the normally closed contacts of a relay.
I also proposed that we use a string of low voltage bulbs as the resistance. When hot they have high resistance. this way they draw less current when the PSU is at it's highest voltage.
As the PSU voltage drops the bulb filament cools and the resistance drops. This pulls more current than a fixed resistor would.
A completely cold filament has a resistance roughly 8% to 10% of the fully hot filament.
two 24V ½W bulbs have a cold resistance of ~200r and ~2300r when hot. This would suit a 50V supply.
The bleeder is attached through the normally closed contacts of a relay.
I also proposed that we use a string of low voltage bulbs as the resistance. When hot they have high resistance. this way they draw less current when the PSU is at it's highest voltage.
As the PSU voltage drops the bulb filament cools and the resistance drops. This pulls more current than a fixed resistor would.
A completely cold filament has a resistance roughly 8% to 10% of the fully hot filament.
two 24V ½W bulbs have a cold resistance of ~200r and ~2300r when hot. This would suit a 50V supply.
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