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.
