Hello All,

I designed High Voltage, Current Limiter power Supply.
Which designed to give 40-100mA current output. which set by "R2" Resistor.

Simple 1N60 - N-CH mosfet get broken every start, due to high current draw of the empty capacitors (C1,C2,C3).

1. If the capacitors are not empty (over 50VDC), the 1N60 work fine.
2. If i change to 4N60 which is stronger mosfet, the circuit works fine every start.

The principle of operation of the circuit:

230VAC go through D5,6,7,8 for AC to DC converter.

By R7,3,1 the Mosfet get on, and D3 (Zener) limit the mosfet gate voltage to 10VDC.

By R2, i set the maximum current output of the circuit.
if R2 Voltage above 0.3V, the NPN (2N2222) decrease the mosfet gate voltage. and by that, the Transistor control the Mosfet for current limit.

I think the N-Ch Mosfet get on very fast, and react more quickly than NPN Transistor, and the current draw of the empty capacitor, is over 1A, which cause the Mosfet to blow when i switch on.
So the simple solution, is to make the Mosfet get on slowly.

someone have idea how to apply it simply?

I do not want to solve the problem by stronger Mosfet, like 4N60, it more expensive and the circuit should be economic.

Thank you

 

So the simple solution, is to make the Mosfet get on slowly.

Not necessarily. A partly-turned-on FET dissipates a lot of power, so the quicker it turns on the better.

 

Not necessarily. A partly-turned-on FET dissipates a lot of power, so the quicker it turns on the better.

Its linear..............

 

Not necessarily. A partly-turned-on FET dissipates a lot of power, so the quicker it turns on the better.

The mosfet is never full On.
In this Circuit the mosfet act as power Resistor. the power dissipates on the mosfet it the main idea of this circuit.

it is Linear circuit. like current-voltage regulator.
If my load is draw 160V in 50mA, the Mosfet absorbent 80V 50mA (240V Main Voltage less 160V Load Voltage).
which is about 4W of heat. and it fine. this is the purpose of this circuit.

i only need take care that 1A mosfet will not blow up in the first capacitor charge. the initial current is too high.

 

Hello,

We do not allow transformerless powersupplies.
See the User Agreement for details.

Bertus