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The drawing below shows a basic full wave vacuum tube high voltage power supply. Two types of rectifier tubes are shown, one
without a cathode and one with a cathode. Also shown are two different types of filter networks, one using a choke inductor and
the other a resistor. It does not matter if the rectifier tube has a cathode or not. The important thing to remember is that with the rectifier without a cathode, can not have any part of the filament grounded. Make sure you use a tube that can handle the voltage and current needed from the supply. In either case, the DC voltage to be expected at the cathode (or filament) is 1/2 the secondary voltage times 1.414. So if you have a secondary that is 500VAC center tapped, then the DC would be 250 times 1.414 or 354 volts. The filter network using an inductor (L1) will have less loss. The filter network using a resistor will have a voltage drop. In the case of a circuit drawing a lot of current, the drop across the resistor can be quite high. In the case of a power amplifier drawing high current, using the inductor is better. For a pre-amplifier or any low current circuit a resistor works fine. The inductor is usually around 300 to 1000 Henries. A resistor can be 500 ohms or higher. C1 should never be higher than 10MFD or the tube may be damaged on power-up. C2 can be any value from 10MFD to 400MFD, the higher the value of C2 the better filtering and voltage stability will be. |
VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE
VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE
VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE
VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE - VACUUM TUBE HIGH VOLTAGE