Many Electronic circuit projects in simple ways of learning

0-40V adjustable voltage regulator at 1A

This is a power supply circuit, 0-40V adjustable voltage regulator, 1A current output. We can use a variable voltage regulator IC, LM723. If we want a higher voltage than them, use better L146.

Although is known less. But enough buy them. Depending on the needs of the builder

How it works
This circuit has the output current limit section and continuously adjusted. The table below shows the values of used equipment. To change the properties of a three circuits model for the maximum output voltage to 30 volts, 40 volts, and 60 volts.


0-40V adjustable voltage regulator circuit diagram

The circuit is an adjustable output of 40 volts / 0.8 Amps. Which we use the L146 is main, due to the output voltage can be higher than the number LM723. But not equal to the lowest pressure, is about 2 volts.

The network resistors are R3, R4, and R5, R6 use for adjusted the offset of this voltage, makes the output can fine to zero volts with P2. And by these resistors will help we have the voltage control at pin 4 and pin 5 of IC1 constant and not stop working.

Although the circuit input voltage drops below the required level.

This the circuit design, there is special driver T3. When the output voltage is loaded lower than a voltage regulated, the volts at pin 4 also will lower pin 5, the IC1 will offset, with increased the volt output at pin 9, but pin 9 is connected to ground by R7 and D2 that as limit the maximum voltage.

Although the voltage cannot be increased, the current is increasing. Therefore, using R7 limits the current to 6 mA. This current flows through the IC1 from pin 11 and to pin 9.

As a result, the voltage drop across the P1, also drive T2. If the voltage is increased, T3, it will take less current. At spindle of P1 is connected to T1, to control the current limiting circuit.

When a drop across voltage R1 over 0.6 volts, the P1 will be short circuit by R1 and T3 stop conducted current.

If the circuit limited current out away, the voltage drop the P1 is constant to 1.2 volts (voltages diode D1 and pin B -pin E of T2).

And this some volts is mixed to a drop volts R1 to driver transistor T1 get a few voltages and mix someone of P1.

If it over to 0.6 volts when T1 will conduct current makes T3 stop running as limiting current just only, as a result, we can control the output current from zero to maximum.

Notice that, LM723 can use maximum of only 36 volts but L146 resist up to 80 volts. And if will use L146 should use an input voltage from the transformer that provides higher volts than 24V but under 48V.

And must change T3 to Number: 2N3442 because 2N3055 resisted volts only on 60V

The table below is shown the value of parts that use in changing the special feature circuit of 3 model, depends on the size of voltage. But whether it be the voltage and current. Do not get T3 be losing power up to 40 watts.

It can supply 0.8A of load current. And there is an adjustable output range of 0V to 40V. Which we can use two 2N3055 transistors in parallel together to supply output current up to 2 times. Also, we must use the transformer 2 amperes.


Keep reading: ‘0-50V 3A DC Variable’ »

This Post Has 4 Comments

  1. Project very use full
    but produce
    should not be equipment

  2. can i us more add 2n3055 for more curren in this circuit

  3. Shitty translation. At least link to the original source!

  4. Hi, iftikhar ahmed

    Yes you can use.
    But it lower than 40V output.

Leave a Reply

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

Close Menu