Probe domestic switch needle KG-300K needle head diameter is 3.0mm normally open switch needle

MOS power IC full range

DFN1006 TP-RCLAMP3321P ESD Diode Low Capacitance

The switching power supply for the amplifier is an isolated high-power AC/DC switching voltage converter. It directly inputs 220V mains, and is isolated and converted into two-way ±33V DC output by the power supply, which is equivalent to the voltage transformer combination of the step-down transformer and the rectified and filtered power. The nominal power is 200W and the maximum is 260W. Most of the amplifier boards and fool power amplifier circuits are used.

Power amplifier dedicated switching power supply

Circuit working principle: The circuit consists of four parts: input rectification and filtering, secondary soft start, switching voltage conversion and low-voltage high-speed rectification and filtering output. Before entering the high-voltage rectification, the utility power passes through the filter circuit composed of L1 and capacitor to eliminate the high-frequency noise wave interference that may be generated, and then sent to the high-voltage rectifier for rectification. The pulsating DC high voltage is filtered by the 510Ω high-power resistor to the high voltage. Electrolytic capacitors are current limited. When the voltage of the fifth pin of the switch control circuit UPK2439 rises to about 100V, the switch control circuit is activated, L2 and L3 generate high-frequency turtle pressure with small amplitude, and L4 generates induced electromotive force through magnetic coupling, and secondly has smaller energy. Output. When the voltage of the fifth pin rises to 200V, the induced electromotive force in L4 is sufficiently large. After rectification and filtering, the transistor 9014 is turned on, and the forward voltage is applied to the thyristor trigger pole to be turned on by the 120Ω resistor. On the other hand, the high-voltage main circuit also adopts NTC high-power soft-start component delay to limit the surge current impact during cold-start to complete the secondary soft-start boot process.

The heart of the switching power supply is a high-speed switch control conversion driving circuit, which is a double-ended driving circuit, which not only ensures the stability of the entire power supply, but also makes the peripheral circuit very simple.

Component selection: 1 and 5 terminals of UPK2439 are 300V high voltage DC input, 2 and 4 terminals are excitation output, and 6 and 7 terminals are connected with isolation transformer 3 end for conversion input. The isolation transformer T is made of E42 high-frequency ferrite core, and the secondary output voltage can be increased or decreased by changing the number of L5 and L6 turns. Low-voltage rectification uses high-speed fast recovery high-current diodes. When equipped with 2000uF filter capacitors, its output DC voltage is very smooth and pure.