I want to add bleeder resistors to my power supply so the caps are discharged when the amp is powered down for safety purposes. Do I run the resistors between the + and - on the DC out to the amp?
Thanks in advance
Thanks in advance
Yes.
You need to choose the resistor values (ohms, watt rating) to discharge the PS caps to a safe level in a reasonable time, but not 'load down' the PS by adding a significant current draw during normal operation.
There are online tools/worksheets for doing the calculation or you can do the math 'from scratch'.
The simplest circuit design is also the easiest to remember: just connect a bleeder resistor directly across the terminals of each electrolytic capacitor.
My own preference is to use flameproof resistors rated for 1 watt, and then choose a resistance value R such that the power dissipated in the resistor will be (1/2) watt or less. So for example if the DC supply voltage is 54 volts, I would choose R >= 5.83K. Namely, 6.2K with 1 watt rating. Personally I don't care whether the bleed-down takes 10 seconds or 120 minutes. Other people may have different opinions about this.
My own preference is to use flameproof resistors rated for 1 watt, and then choose a resistance value R such that the power dissipated in the resistor will be (1/2) watt or less. So for example if the DC supply voltage is 54 volts, I would choose R >= 5.83K. Namely, 6.2K with 1 watt rating. Personally I don't care whether the bleed-down takes 10 seconds or 120 minutes. Other people may have different opinions about this.
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