| 摘要 |
1285624 Frequency control ALLEN BRADLEY CO 18 Aug 1969 [3 Oct 1968] 41056/69 Heading G4H During successive predetermined time intervals represented for example by 100 pulses from 1 MHz oscillator 10, the voltage from a potentiometer 28 is compared with a sawtooth reference voltage, the comparator enabling a gate 14 to pass clock pulses from oscillator 10 until its inputs are equal. The pulses from gate 14 may be fed to a divided by 100 circuit 34 of the average output frequency from which represents the input from potentiometer 28 derived from a control device 31. As described the oscillator output is fed to a frequency divider 12 connected to the base of a transistor 15, the emitter and collector of which are connected to the terminal of a capacitor 16. Transistor 18 is connected to charge capacitor 16, the emitter collector path of transistor 15 discharging the capacitor to produce the sawtooth voltage to comparator 26. |
