100W VMOS tube inverter power supply circuit

This device has a simple circuit, easy debugging, reliable performance, automatic conversion between inverter and charging, and battery power indicator. Due to the use of high-power VMOS tubes, it has high efficiency and low cost, making it suitable for assembly by electronics enthusiasts. working principle　　

VT1 and VT2 form a multivibrator with an oscillation frequency of 5Hz. When the voltage drops, in order to keep the frequency constant, the oscillator is powered by the voltage regulator tube VD1. The square wave voltage output by the multivibrator directly drives the VMOS high-power tube, and the 220V AC power boosted by the transformer is drawn from the socket CZ. Relay J1 is used for automatic conversion of inverter and charging. When the power grid is sending power, J1 is energized, then J1-3 is connected to the power grid, and J1-2 jumps from pin ⑧ to pin ⑤ of transformer T, causing transformers ① and ② to generate an AC voltage of 15V to pin 0, and J1-1 is turned off. Turn on the multivibrator power supply, so the gate voltage of the VMOS tube is zero. At this time, the VMOS tube is equivalent to a diode. The 15V AC power is fully-wave rectified by the VMOS tube to charge the battery. LED1 indicates the end of charging, and LED2 indicates the end of discharge. Neon lamp LD indicates high voltage. When the grid is sending power but the battery is sufficient, or there is a power outage but the inverter is not required to operate, turn off the power switch S1. Winding wire diameter (mm) Number of turns (T) 0-1, 0-2 2 33 3-4 0.4 440 4-5, 6-7 0.4 66 7-8, 8-9 9-10 5-6 0.4 28 yuan See the table below for device selection and production component list. No. Name Model Quantity No. Name Model Quantity R1, R2 Resistor 2.2K 1/4W RT 2 VT1, 2 Transistor 3DG6 β=100-150 2 R3, 4, 5, 6 Resistor 100K 1/8W RJ 4 VT3 Transistor 3DG Small Power tube 1 R7 Resistor 1K 1/2W 1 VT4 Transistor 3AX Small power tube 1 R8 Resistor 470Ω 1/2W 1 VT5, 6 VMOS tube V75AT 2 R9 Resistor 1M 1/4W 1 S1 Switch double pole single throw 1 RP1, RP2 fine adjustment Resistor 200K 2 S2 switch single pole five throw 1 RP3, RP4 trimmer resistor 2.2K 2 J1 electromagnetic relay 220V 3 groups normally open and normally closed 1 C1, C2 polyester capacitor 0.1u 2 VD1 Zener diode 2CW17 9V 1 C3 electrolytic capacitor 2200u/25V 1 E Battery pack 12V 40AH 1 When all components are welded and checked correctly, turn on the 12V power supply. The circuit should be able to start oscillating. Use an oscilloscope to observe the VT1 and VT2 collector voltage waveforms. Adjust RP1 and RP2 to 50Hz, and the waveform symmetry. Change the power supply voltage and adjust RP3 so that LED1 lights up when the power supply voltage is 16.8V and goes out when the power supply voltage is below 16V. Adjust RP4 so that LED2 lights up when the power supply voltage is greater than 11V and goes out when it is less than 10.5V. 2CW17 should be able to provide 9V DC voltage to the multivibrator when the power supply voltage is between 10.5-17V. Other parts of the circuit do not require debugging. The core cross-sectional area of ​​the transformer should be no less than 10cm2. The winding data is shown in Figure 2 (the winding data is shown in the table above). When ③ and ⑧ are powered by 220V AC, the voltage at terminals 0-1 and 0-2 is 11V; ⑦, ⑥, ⑨, and ⑩ are designed to adjust the inverter voltage; when ③ and ⑤ are powered by 220V AC , the voltage at terminals 0-1 and 0-2 is 15V, used to replenish the battery power; when ③ and ④ are supplied with 220V AC, the voltage at terminals 0-1 and 0-2 is 17V, used to replenish the discharged battery. Perform fast charging. When the power grid fails, the inverter will automatically put into operation, the inverter voltage is drawn from the socket, turn on the power switch, the neon lamp should glow, and LED2 should also glow (green). When the green light goes out, it means that the battery has been discharged and the inverter should be stopped. It should be noted that the battery should not be depleted for a long time, nor should it be used for a long time after being fully charged. It should be discharged for about 1 hour a week, and it should be fully charged in time after being discharged. It should be completely discharged once every one or two months, and it should be fully charged in time after discharge.