Electric car charger principle, the charger control chip is generally based on the TL494 as the core, to promote the 2 13007 high voltage triode. In combination with LM324 (4 operational amplifier), the three stage charging is realized. 220V AC rectifier through D1-D4, C5 filter to get about 300V direct current. This voltage charges the C4 and initiates the current through the TF1 high voltage winding, the TF2 main winding, and the V2. The TF2 feedback winding generates an induced voltage that turns the V1 and V2 in turn. Therefore, the low-voltage power supply winding in TF1 generates voltage through D9, D10 rectification, C8 filtering, and supplies power to the TL494, LM324, V3, V4 and so on. The output voltage is low at this time. After the TL494 is started, its 8 feet and 11 feet rotate output pulses to drive the V3, V4, and the TF2 feedback winding to drive the V1, V2. The V1, V2, from the self-excited state into a controlled state. TF2 output winding voltage rise, this voltage by R29, R26, R27 voltage, feedback to the TL494 1 feet (voltage feedback), so that the output voltage is stable on the 41.2V. R30 is a current sampling resistor that generates a voltage drop when charging R30. This voltage is fed back to the 15 pin of the TL494 (current feedback) via the R11, R12, so that the charging current is constant at about 1.8A. In addition, the charging current produces a voltage drop on the D20 and reaches the 3 pin of the LM324 through the R42. The 2 foot high voltage output light charging lamp, and 7 feet output low voltage, floating lights. The charger enters the constant current charging stage. Moreover, the 7 pin low voltage pulls the voltage of the D19 anode. Reduce the TL494's 1 pin voltage, which will cause the charger to reach a maximum output voltage of 44.8V. When the battery voltage rises to 44.8V, it enters the constant voltage phase. When the charging current is reduced to 0.3A - 0.4A, the LM324 3 pin voltage is reduced, the 1 pin output voltage is low, and the charging lamp goes out. At the same time, 7 feet high output voltage, floating light. Also, the 7 pin high voltage raises the voltage of the D19 anode. To raise the TL494's 1 pin voltage, this will cause the charger to lower the output voltage to 41.2V. The charger into the float.