PURPOSE: To remove the useless consumption of electric power and to expand and contract an antenna efficiently by differentiating the whole length of the antenna by the number of pulses generated from an oscillator and counting the number of pulses to control the expansion of the antenna.
CONSTITUTION: The number of counts set up by the positions of antenna switching terminals F, H and switches S1∼S4 is outputted from a decoder 2A to a comparator 4A. The output of a counter 3A is "0" until the time just before operation, the comparison of outputs between the decoder 2A and counter 3A by a comparator 4A is A>B and a pin 13 is the high level. A transistor (TR) 1 of a control circuit 6A actuates a relay Re1 and a motor causes the antenna to extend. Simultaneously, a pin 3 of the comparator 4A is turned to the low level and an oscillation circuit 5A is oscillated through an inverter I. The counter 3A counts up the number of pulses of the oscillation circuit 5A, and when A=B is satisfied, the pin 13 is turned to the pin 3 and the TR1 of the control circuit 6A is turned off, stopping the motor. Since the pin 3 is turned to the high level simultaneously, the oscillation circuit 5A stops operating. Thus, the expansion of the antenna can be performed efficiently.
ONODA MASAHIDE
MAO YASUHISA
