Pen recorder marker pulse generation - by comparison of analog signal with staircase voltage, giving frequency-rate relationship

摘要

The circuit is for generating masking pulses with repetition frequencies dependent on the recording speed for the recording tracks of analogue pen recorders is constructed solely of electronic components. The lowest value bits of the output of an analogue-to-digital converter are changed to produce the pulses with the appropriately varying frequency. The analogue signal is applied to the converter input. The converter conversion rate and quantisation are chosen according to the max. rate of change of the analogue signal for a given recording device so that no more than a change of one quantum occurs between successive conversions. The analogue signal is compared with a staircase voltage in a comparator (7,7') whose output drives a flip-flop (10,10'). The flip flop output is a pulse signal whose repetition rate varies with the rate of change of the analogue signal.