A one-shot delay timer 4 is provided by a pair of comparator timers 14 and 18. The first comparator timer 14 responds to an input signal and provides a delayed output initiating the output pulse. The second comparator timer 18 provides a delayed output terminating the output pulse. The delayed output pulse of controlled length is generated for each input signal except when a second input signal occurs before the termination of the one-shot output pulse. The delayed output pulse is generated regardless of the duration of the input signal, even if the input signal lasts longer than the termination of the output pulse. Timer 4 is ideal for proximity switch applications, particularly photoelectric type proximity switches, for providing a delayed output signal following a given sensed condition.