Product Profile of DC Regulated Variable Power Supply

Kits N Spares offers DC Regulated Variable Power Supply. Kits N Spares supplies various types of digital security systems, digital voltmeter, electronic auto dipper, electronic guard etc. By using DC Regulated Variable Power Supply user can obtain the following voltages at a current limited to one ampere: 3.3V, 5V, 6V, 9V, 12V and 15V. The AC main is stepped down by transformer X1 to deliver the secondary output of 18V AC at a maximum current of 1A dependant upon the load.

DC Regulated Variable Power Supply has the following features:

• Using this circuit, you can obtain the following voltages [approx.] at a current limited to one ampere: 3.3V, 5V, 6V, 9V, 12V and 15V.

• The AC main is stepped down by transformer X1 to deliver the secondary output of 18V AC at a maximum current of 1A dependant upon the load.

• The transformer output is rectified by the bridge rectifier comprising diodes D1 through D4, filtered by capacitor C1 and fed to regulator IC LM317, which is a 3-terminal positive regulator capable of providing 1.2V to 37 volts at 1.5A current to the load.

• Resistor R13 and selected combinations of resistors R1 through R12 are used to produce approximately 3.3V, 5V, 6V, 9V, 12V and 15V at the output.

• The desired resistors are selected by switching into conduction one of the six pnp transistors T1 through T6 by grounding the corresponding transistor base using rotary switch S1.