Apparatus for driving electric load

摘要

An apparatus for driving an electric load includes a switch device interposed in a current feed path from a direct-current power source to the electric load. A sensing resistor connected in series with the switch device operates for detecting a load current as a voltage value. The load current flows into the electric load via the switch device. A signal generation device operates for generating a trapezoidal wave signal in response to externally applied commands to turn on and turn off the electric load. The trapezoidal wave signal gradually varies from a first predetermined voltage to a second predetermined voltage when the electric load starts to be turned on. The trapezoidal wave signal gradually varies from the second predetermined voltage to the first predetermined voltage when the electric load starts to be turned off. A control device operates for comparing the trapezoidal wave signal generated by the signal generation device and the voltage value provided by the sensing resistor, and for controlling the switch device in response to a result of the comparing so that the load current will vary in accordance with the trapezoidal wave signal.