Signal generator with constant keying ratio - has low pass at clock pulse generator output, comparator, and reference voltage divider

摘要

The signal has a presettable, constant keying ratio and the generator consists of a clock pulse generator (TG), to whose output is linked a low pass (TP). There is a comparator (KO) , a reference voltage (UO) voltage divides (R1,2), and a coupling between the divider part-tap and the comparator comparison input. There is a coupling between the low pass and another comparator input. A control loop extends from the comparator output to a frequency determining clock pulse generator input. Pref. the voltage divider ratio is variable for the adjustment of the keying ratio.