Feature: 1. The circuit architecture is very good, far more advanced than three terminal voltage regulator and WJ power supply. 2. With excellent wiring and good linear components, the output precision is very high, low ripple. 3. Double-sided PCB board, stable performance, durable in use. 4. Premium components: Schottky rectification tube, for NOVER capacitor, ON tube king 15034 output tube, adjustable resistor. 5. Double operational amplifier TL072 is used for plate reference voltage regulation. Specification: Item Type: Regulated Power Supply Board Material: Plastic, aluminum Maximum Operating Current: 1.5A, 2 channels are 3A Input Voltage Range: Double 9V - double 24V (4-wire transformer) Output Voltage: +/- DC 5V to DC 28V or double DC 5V to double +28V, with short circuit protection Maximum Output Current: 2A PCB Size: 102x118x37mm / 4.02x4.65x1.46in There are three gear positions for voltage regulation of the board, which are: H (high) output voltage above 20V, the highest 28V, suitable for discrete components of the voltage level circuit. M (medium) 12-18V, suitable for preamplifier. L (low voltage) output 5V-9V, suitable for DAC power supply After setting the gear, fine-tune the adjustable resistor to reach the exact value. The corresponding resistance of H is 33K, and the corresponding resistance of M is 12-18K (the higher the resistance is, the higher the voltage is, but the lowest voltage will also increase). The corresponding resistance of L is 3K3-6K8 When you want to use 2 independent single and double DC outputs, such as 5V and 9V, you can output directly from the green terminal. If you want to set positive and negative power supply to the operational amplifier, you can short-circuit the fly wire above the gold-plated bonding pad in the middle, and then output positive voltage from VCC and negative voltage from GND grounding VSS. Package List: 8 x 5A Rectifier Tube2 x 8-bit Op Amp Seat4 x 2-position Terminal Block2 x BD104 4 x BD1392 x 1503420 x BI Adjustable Resistor 10K2 x 6800μF/35V2 x 470μF25V2 x 100μF35V2 x Large WIMA1044 x 47μF25V4 x High Copper Column4 x Nut3 x Screw2 x 2N54014 x Red Light2 x TL0722 x Black Heat Sink4 x Insulated Terminal6 x Plastic Spacer1 x PCB Board2 x R22J 4 x 41482 x 47332 x Color Ring 220P48 x Resistor