Many electronics circuits and projects for learning in simple ways.

# 10V to 350V Adjustable Regulator DC Power Supply

Here is an adjustable regulator DC power supply circuit that can be provided the output high voltage is 10V to 350V. It use the transistor is based so we use often use them.

Now, a transistor can tolerate more high pressure. For example; in this circuit we will use number of BU 111 or BU 126 or BUY 76.

The transformer, need to have a 300 volts high voltage coil, and the 9 volts low voltage coils to the controller circuit.

Then, the AC300V will flow to the rectifier by diodes D1 to D4 to DC 420 volts, which is very high voltage. Thus we need to use two the 350V- electrolytic capacitor are connected together in series. Both resistors R1 and R2 that parallel with the capacitors will determine voltage drop across both capacitors same voltage.

The resistors-R5 is used reduce loss inside the T1- RC networks (R3, R4, C3, C4) at the collector lead of T1 are used to adjust the output voltage about 350 volts. Both transistors T2 and T3 can use number of BC 547 because does not need get a high current and voltage. The diode-D7 protect the base of T3 from the peak negative voltage.

The threshold current 4 level can adjust by 2 the push bottom switches as follows;
– 1 mA (ON both circuits)
– 5 mA (S2- OFF circuit)
– 15 mA (S2 and S3 OFF circuit)
– 50 mA (S3 OFF circuit) at full load and voltage across the R8 to R11 2.8 volts.

Which is voltage to drive the base lead of transistor that use control operation of T3 by through diodes D9 to D12. Thus, this transistor will stop conduct current if the output current more than the setting voltage. This current is watched by 1mA meter. The switch S4 use for ON/OFF the meter.

The output current will be limited if over more than the setting about 10 %. The output voltage can control by P1, from 10 to 350 volts, P2 is finely tuned again. This circuit can protect the short circuit for long times.

## Related Circuits

### This Post Has One Comment

1. we are interested in Power supply designs specially High Voltage 0-300v. 500mA ,
do you have these type of circuits.

This site uses Akismet to reduce spam. Learn how your comment data is processed.