Online simulation of the детектор отсутствия импульсов на чипе 555 circuit

This circuit uses a 555 timer chip to detect a missing pulse. The input signal is a square wave. When you click the logic input ("L") to bring it high, the input will stop oscillating and stay high. The 555 will detect this and set the output low. The 555 is connected as a monostable. But whenever the input goes low, it turns on a transistor that quickly discharges the capacitor. When the input goes high, the capacitor recharges, but it doesn't reach the threshold voltage before the input goes low again. If the input stays high, the capacitor is allowed to charge fully, and the 555 timing interval ends, resulting in a low output.

This page is a utility for simulating детектор отсутствия импульсов на чипе 555 online with specified initial values.