Patent ID: 8035316

Claim:
A current-limiting protection circuit of remotely controlled ceiling fan-lamp, comprising: a remote control signal demodulation unit for receiving control signals and demodulating the control signals; a lamp load driving unit for driving a lamp load to work, the lamp load driving unit including a triac; a fan load driving unit for driving a fan load to work; a sampling unit including a sampling resistor, a first terminal of the sampling resistor being connected to the lamp load via the lamp load driving unit, while a second terminal of the sampling resistor being grounded, the sampling unit serving to pick up sampled voltage signals reflective of the power used by the lamp load; a signal amplifier unit including an amplifying control chip, an in-phase input terminal of the amplifying control chip being connected to the sampling resistor for amplifying the sampled voltage signal; a comparison unit including a comparison control chip, an in-phase input terminal of the comparison control chip being connected to an output terminal of the amplifying control chip for converting a sine wave amplified sampled signal into a rectangular wave signal; and a controlling unit including a microcontroller unit, a current-limiting signal input terminal being connected between the microcontroller unit and an output terminal of the comparison control chip, whereby the rectangular wave signal can be transmitted to the microcontroller unit, a lamp load control signal output terminal being connected between the microcontroller unit and the lamp load driving unit for outputting control signal to control the lamp load driving unit, whereby in the case the microcontroller unit detects that the positive bandwidth of the received rectangular wave signal is larger than a preset nominal value, the microcontroller unit outputs a control signal to change the conduction phase angle of the triac of the lamp load driving unit and lower the power used by the lamp load to a value not higher than the nominal value.