| 摘要 |
<p>1,114,745. Multivibrators. GEBRUDER SCHMIDT METALLWARENFABRIK. 21 July, 1965 [25 July, 1964], No. 31045/65. Heading H3T. [Also in Division G3] A battery-operated multivibrator has the pulse repetition rate made independent of changes in the internal resistance of the battery by arranging that a capacitor is charged by the battery through a load in one half-cycle and then charges a further capacitor during the other half-cycle. In Fig. 2 capacitor C2 is charged by the battery through diode D and acts as voltage source for the frequencydetermining capacitor C1. When the transistors conduct, C2 discharges through T2, NTC, R2, C1 and the base-emitter path of T1 to charge up C1 If the mark-to-space ratio is very large, e.g. with one pulse per minute, the diode may be replaced by a high resistance. Relay contacts may also be used instead of a diode. The load may be a relay Ra driving a clock or perpetual calendar. Resistor R4 controls the interval between the pulses.</p> |
