| 摘要 |
<p>PURPOSE:To eliminate the need for revision of components when a VCO self- running oscillating frequency is revised with respect to the voltage controlled oscillator capable of automatically switching the self-running oscillating frequency. CONSTITUTION:The voltage controlled oscillator provided with a CR time constant circuit comprising a capacitor and a resistor and oscillated at a self- running oscillating frequency (Figure A) is provided with a frequency setting circuit 16 (Figure B) in which resistors R10, R11 are connected to resistors R7, R9 via switches SW1, SW2, the time constant is changed by controlling the switches externally to select the self-running oscillating frequency, and another capacitor CX is connected to a capacitor C whose charge/discharge current is changed to select the self-running oscillating frequency via a SW 3 (Figure C), the switch SW3 is controlled for its switching externally to change the CR time constant thereby selecting the oscillated frequency.</p> |
