| 摘要 |
FIELD: electricity.SUBSTANCE: invention relates to a circuit and a method of monitoring load current and a fire alarm control device, wherein the circuit comprises a power source, a load current sensing resistor for monitoring the load current and a main switch for controlling connection and disconnection of the power source and further comprises a bias circuit on a metal-oxide-semiconductor field-effect transistor for controlling the main switch, an amplifier circuit for converting the value of the load current passing through the load current sensing resistor to a voltage value, an operational circuit for disconnecting the power supply channel and transmitting a signal indicating the state of the load current when the voltage value exceeds a threshold, and a clamping circuit for holding the overload current signal. Once the load current exceeds a predefined threshold, in other words, when there is overload current, the power supply channel of the power source is disconnected, and the state of overload current is blocked for 50 mcs to avoid compromise of normal power supply of internal circuits of the controller.EFFECT: enabling use to monitor user device load.14 cl, 9 dwg |
