Hello all
I’m hoping to get some help on a project I’m looking at doing. I want to build a bench power supply for my LAB that will provide a variable DC supply at about 100mA from a 240v ac supply from my bench isolation transformer.
The reason for this supply is to test valve amp projects before building the final circuit. I wanted the supply to be variable from about 10v to the full 300v dc.
I have already constructed one design attached in image 1 below which for voltage control from 0v to 300v worked very well. However I have found that the output voltage can swing high when switching on as it is unregulated. I tried the circuit powering a heater element at 45vdc and when switching it on the voltage spiked to 55vdc then back down again. This destroyed the valve filament.
I am looking at the other circuit in image 2 which is a regulated supply. Has anyone built this and is it stable. What sort of output current could I get from this circuit.
I have an idea to build the first unregulated circuit for the plate voltages as this can be fairly unregulated, and then the second circuit for the heater elements at a lower input voltage about 80v ac.
Any help would be much appreciated I am a newbie to this I have experience with HV circuitry but not with designing the circuit.
I’m hoping to get some help on a project I’m looking at doing. I want to build a bench power supply for my LAB that will provide a variable DC supply at about 100mA from a 240v ac supply from my bench isolation transformer.
The reason for this supply is to test valve amp projects before building the final circuit. I wanted the supply to be variable from about 10v to the full 300v dc.
I have already constructed one design attached in image 1 below which for voltage control from 0v to 300v worked very well. However I have found that the output voltage can swing high when switching on as it is unregulated. I tried the circuit powering a heater element at 45vdc and when switching it on the voltage spiked to 55vdc then back down again. This destroyed the valve filament.
I am looking at the other circuit in image 2 which is a regulated supply. Has anyone built this and is it stable. What sort of output current could I get from this circuit.
I have an idea to build the first unregulated circuit for the plate voltages as this can be fairly unregulated, and then the second circuit for the heater elements at a lower input voltage about 80v ac.
Any help would be much appreciated I am a newbie to this I have experience with HV circuitry but not with designing the circuit.
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