The circuit diagram of 25V Adjustable Regulator has been given here. This circuit is based on LM 117 IC which is the central part of this circuit. The LM117 IC is an adjustable 3-terminal positive voltage regulator. This voltage regulator is able to provide in excess of 0.5A over a 1.2V to 37V output range. The added advantages of this circuit is that the ease of handling and the use of only two external resistors for setting the output voltage.
In this circuit, voltage adjustment is done by using the resistors R1 and R2. This power supply for this circuit is able to deliver a maximum of 0.5A current. By adjusting the potentiometer R2, required voltage can be obtained. To reduce min output voltage from 1.2 volt to 0V, connect two IN4007 diodes in series to the output.
LM 117 Pin Diagram
- For getting a 1.2A output current replace LM117 with LM317.
- This circuit is easy to assemble and provides great results.
- Adequate heat sink should be provided for IC LM 117.
- To get a 1.2A output current replace LM117 with a LM317.
- You can use as less as 5V DC as input voltage. Here a minimum 28V, 2A DC input is needed for the IC as shown in figure.
- If exact value components are not available then try the nearest ones.