A valve timing controller of a motor utilizing type has a control circuit
for generating a control signal, and a driving circuit for turning-on and
driving the motor in accordance with the control signal generated by the
control circuit. The control circuit for receiving a motor rotation
signal showing the real rotation speed of the motor, and an engine speed
signal showing the real rotation speed of the engine generates the
control signal on the basis of the motor rotation signal when the real
rotation speed of the engine is less than a reference value. The control
circuit also generates the control signal on the basis of the engine
speed signal when the real rotation speed of the engine becomes the
reference value or more.