| 摘要 |
A circuit for supplying a pulse train to a utilizing device such as a stepping motor includes a timer for providing a pulse train which varies between two adjustable frequency limits, signal generating means, isolation and drive means, timer control means, and means controlled by the timer and capable of compensating for variations in components within the timer for controlling the inputs to the timer to maintain the desired frequency limits. The timer control means includes capacitive and resistive means and a gate capable of controlling the timer to provide a ratio of substantial magnitude between the upper and lower frequency limits. Additional means are provided for adjusting the frequency limits and the ratio therebetween. |
