I’m assembling a battery eliminator with some spare parts that I have to power filament and plate voltages for home brew experimental regen radios to build. Can any forum member suggest an all around resistance value and wattage for a bleeder resistor for my circuit below?
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The Radio Board.org
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Why do you want a bleeder? To discharge the filter caps when the supply is OFF? The Zener string is already conducting at least 10 mA (see data sheet) and will discharge the caps (eventually). If the desired discharge time is really 0.05 seconds, you don't need a big resistor. 2 Watts should be fine. Rich PS: 250 ohms is way too low. It will draw 400 mA steady state at 100V output. This kind of circuit is intended for radios that draw under 50 mA steady state.
I did a quick chatgpt4 question on this. If it's correct, and there is no guarantee that it is even close, then the resistor is huge. I'm not an engineer, but here is the AI answer It's fun to try AI
"To calculate the resistor value and wattage required for your power supply, you will need to know the desired output voltage and current. Assuming you want to limit the output voltage to 120V DC and the current to 1A, you can use Ohm's law to calculate the resistor value:
R = V / I = 120V / 1A = 120 ohms
To calculate the power rating (wattage) of the resistor, you can use the formula:
P = V^2 / R = 120V x 120V / 120 ohms = 120W
Therefore, you will need a resistor with a value of 120 ohms and a power rating of at least 120 watts to limit the output voltage of your power supply to 120V DC and the current to 1A. "