220V alternating current through the T0 bidirectional filtering to suppress interference, D1 rectifier for pulse DC, and then through the C11 filter to form a stable 300V about the DC power. U1 for TL3842 pulse width modulation integrated circuit. The pin 5 as the cathode of the power supply, 7 feet for the positive electrode of the power supply, 6 feet is a pulse output direct drive field effect tube Q1 K1358 foot 3 limits the maximum current, resistance adjustment R25 (2.5 Ohm) can adjust the charger of the maximum current.
2 pin for voltage feedback, can regulate the output voltage of the charger. 4 pin external oscillation resistor R1, and oscillation capacitor C1. T1 for high frequency pulse transformer, its role has three.
The first is to put the high pressure pulse into a low voltage pulse.
Second is to play a role in the isolation of high voltage, to prevent electric shock.
Third is to provide a working power supply for uc3842. D4 for high frequency rectifier tube (16A60V) C10 for the low voltage filter capacitor, D5 for the 12V voltage regulator diode, U3 (TL431) as a precision reference voltage source, with U2 (photo coupler 4N35) to automatically adjust the role of the charger voltage. The adjustment of W2 (voltage trimming resistor) can fine charger. D10 is the power indicator light. D6 for charging indicator light.
R27 is a current sampling resistor (0.1 ohm, 5W) changes the resistance of the W1 can adjust the charger turns the turning point of the floating charge current (200-300 MA) power began when, C11 is 300V voltage of about. This voltage is loaded into the Q1 via T1.
Second via R5, C8, C3, U1 reached seventh feet. Forced U1 start. U1 6 pin output square wave pulse, Q1 work, the current through the R25 to the ground. At the same time, the secondary coil of T1 generates the induction voltage, which is supplied by R12, D3 and U1. T1 output coil voltage by C10, D4 rectifier filter to get a stable voltage. This voltage via a D7 (D7 to prevent the intrusion to the current battery charger to charge the battery.).
The secondary path R14, D5, C9, lm358 (dual operational amplifier, pin 1 to power, 8 feet for the power supply positive) and its peripheral circuits provide 12V power supply. D9 provides a reference voltage for the LM358, the R26, R4 partial pressure reached second feet and fifth feet LM358. Normal charging, at the upper end of the R27 is 0.15 - 0.18V about voltage and the voltage by the lm358 R17 added to the tripod, from 1 foot sends a high voltage. This voltage through a R18, forcing Q2 to conduct,
D6 (red light) lights, second way into the LM358 6 pin, 7 pin output low voltage, forcing the Q3 off, D10 (green light) off, the charger into the constant current charging stage. When the battery voltage up to 44.2V or so, the charger into the constant voltage charging stage, the output voltage is maintained at about 44.2V, the charger into the constant voltage charging stage, the current gradually decreases. When the charge current is reduced to 300mA R27, the voltage on the upper end of the 200mA drops, and the LM358 3 pin voltage is lower than 2 feet, and the output voltage of the 1 foot is low, the Q2 is off, and the D6 is off. At the same time 7 feet output high voltage, this voltage all the way to make Q3, D10 light. The other path D8, W1 to reach the feedback circuit, the voltage drop. The charger into the trickle charging stage. 1-2 hours after the end of charging.