Continuously adjustable positive and negative regulated power supply - Power Circuit - Circuit Diagram

MOS Power IC Full Range

Probe Current Voltage Pin 420x4450 Head Diameter 5.0 Over Current Current and Voltage Pin

Adjustable Capacitor Murata Genuine Original

TZC3Z030A110R00 MURATA Murata Adjustable Capacitor Original Spot

1.5PF SOT23-6 Low Capacitance 5V Breakdown Voltage 6V SRV05

Traditional dual power supplies (positive and negative symmetrical power supplies) lack continuous adjustability, which can be inconvenient during use. In this article, a positive and negative symmetrical regulated power supply with adjustable output voltages has been designed using two three-terminal regulators: 7815 and 7915. These regulators are connected symmetrically to provide both positive and negative voltage outputs that can be adjusted individually or simultaneously. As illustrated in the diagram, the AC voltage output from the transformer at 18V is rectified through diodes D1 to D4. Capacitors C1 and C2 filter the rectified DC voltage. The center tap of the transformer serves as the common ground terminal. The positive and negative DC voltages are then connected to pins 1 and 3 of the 7815 and 7915 regulators, respectively. Pin 3 of the 7815 is linked to the sliding contact 'd' of potentiometer W2, while pin 1 of the 7915 is connected to the sliding contact 'C' of potentiometer W1. By sliding contact 'C' to the '0' terminal (ground), adjusting W2 allows for a positive variable voltage ranging from '+6V to +15V' at the 'a' end. Conversely, sliding contact 'd' to the '0' terminal grounds it, and adjusting W1 yields a negative variable voltage from '-6V to -15V' at the 'b' end. Replacing W1 and W2 with a coaxial potentiometer results in a fully symmetrical adjustable power supply, enabling continuous voltage adjustment from ±6V to ±15V, allowing for synchronized adjustments. It's essential to install heat sinks on the 7815 and 7915 three-terminal voltage regulator blocks in this circuit. The power rating of the transformer depends on the load requirements of the electrical device.