A retriggerable OS can be used as a pulse-frequency detector that detects when the frequency of a pulse input is below a predetermined value. A simple example of this application is shown in Figure 5-99. The operation begins by momentarily closing switch SW1.

(a) Describe how the circuit responds to input frequencies above 1 kHz.

(b) Describe how the circuit responds to input frequencies below 1 kHz.

(c) How would you modify the circuit to detect when the input frequency drops below 50 kHz?

Figure 5-99

Transcribed Image Text:

Input pulses M Jo TOS 10 tp = 1 ms +5 V J CLK K SW1 CLR X OUTPUT +5 V