High Voltage bench supply

Hi All,

I work with Valves (Tubes) quite alot and i am planning to build a variable HV bench supply (600v, 500mA).

I am planning to use a step up transformer, controlled by a multivibrator such as a CD4047 and Vary the voltage and Current by limiting the low voltage to the primary side of the transformer using an lm723.

I am going to use an LCD display, Controlled by arduino, however, i thought to myself- why not use arduino to also run the Multivibrator and low voltage and current limiting?

Can anyone point me in the right direction here as to how to build a sketch-I'm particularly lost as to how I could control current flowing through a pass transistor, using arduino.

Thanks in advance for your help.

Hi,

I am planning to use a step up transformer, controlled by a multivibrator such as a CD4047 and Vary the voltage and Current by limiting the low voltage to the primary side of the transformer using an lm723.

Do you mean a Switch Mode Supply rather than transformer? The transformer is AC to AC, I can't see how you will control it with a CD4047 and a LM723?

If it is only a fixed voltage you need there must be simple designs to achieve it. The arduino could easily monitor voltage and current, but what component you are going to use to regulate the output will probably determine where it is feasible.

Tom....... :)

Hi tom,

The multivibrator is used to produce the AC on the primary side (low voltage in this case) through some mosfets. there is going to be about 15V to the primary centre tap, on the secondary there will be 400vac, which ill rectify again to DC. The 15v o the primary centre tap can be current regulated- thus also current regulated on the secondary side of the transformer.

below is a schematic of similar topology:

http://www.circuitstoday.com/simple-100w-inverter-circuit

Mike

If the aim is to produce 600V at 500 ma , thats 300 watts. How are you controlling the input voltage and current.

And that from 12volts....

30Amp supply?

Mosfets via arduino- PWM to control the voltage, however i am stuck on current control... the idea is to control everything from the low voltage side.

mauried: If the aim is to produce 600V at 500 ma , thats 300 watts. How are you controlling the input voltage and current.

A small current sense resistor in the high voltage negative/return line. 1ohm will drop 500mV@500mA. Arduino can measure that, e.g. with 1.1volt Vref. Leo..