| 摘要 |
PURPOSE: A control circuit of an electric heater is provided to greatly improve safety by automatically cutting off the power of a heating load when a microprocessor controlling the electric heater is damaged by static electricity, lightning and pulse noises. CONSTITUTION: A control circuit of an electric heater comprises: a microprocessor for outputting a high driving signal through the terminal(P1) when a function selecting switch is operated by a user, and consecutive pulse signals through the terminal(P2); a pulse rectifying unit for converting the consecutive pulse signals from the terminal(P2) of the microprocessor to a direct-current power; and a TRIAC driving unit in which the TRIAC turns on by having the gate current flow through a collector terminal of a first transistor to a gate terminal of the TRIAC when the first transistor and a second transistor turn on by the high driving signal output from the P1 terminal of the microprocessor and the direct-current power output from the pulse rectifying unit.
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