| 摘要 |
An abnormal voltage protection circuit of an inverter is provided to protect the inverter safely when an input voltage is in both low and overvoltage states. An abnormal voltage protection circuit includes a zener diode(ZD2), a low voltage comparator(U1), and an overvoltage comparator(U2). The zener diode is connected to an input voltage(Vin), and a switching voltage thereof is set at a reference level of a low voltage. The low voltage comparator has a positive terminal connected between the zener diode and the input voltage and a negative terminal connected to standby voltage(STBY) in a constant voltage state. An output of the low voltage comparator is connected to a low voltage switching terminal of the inverter. The low voltage comparator turns off the inverter by outputting a logic low to the low voltage switching terminal of the inverter when the input voltage is in a low voltage state. The overvoltage comparator has a negative terminal connected to the output of the low voltage comparator and a positive terminal connected to the standby voltage. An output of the overvoltage comparator is connected to an overvoltage switching terminal of the inverter. The overvoltage comparator turns off the inverter by outputting the logic 'low' to an overvoltage switching terminal of the inverter when the input voltage is in an overvoltage state.
|
