TIME DELAY and COUNTERS CIRCUITS
Time Delay Relay
This time delay relay is made up of a simple adjustable timer circuit which controls the actual relay. The time is adjustable from 0 to about 20 seconds with the parts specified. The current capacity of the circuit is only limited by what kind of relay you decide to use.
Time delay relay reduces inrush current
A transformer switching onto a line can sometimes cause a circuit breaker to trip or a fuse to blow. This phenomenon occurs even if the transformer presents no load, such as when the secondary is open. The problem arises because of the heavy magnetizing inrush current in the transformer.
Delay line has wide duty-cycle range
Today's digital delay lines can process pulses no shorter than their delay times, and that restriction confines the devices to applications in which the duty cycle remains near 50%
Wide Range Timer
timer which can be adjusted from 2 ms to 2000 seconds with a single control.
Time Delay Circuit (1 Hr)
A simple battery operated one hour timer device with an audible warning. May be used as a parking meter timer.
5 to 30 Minute Timer
A switched timer for intervals of 5 to 30 minutes incremented in 5 minute steps.
Periodic Timer
A switched timer with equal make and equal space periods timing adjustable from over 6 minutes to 38 minutes.
24 Hour Timer by Ron J
These two circuits are multi-range timers offering periods of up to 24 hours and beyond. Both are essentially the same. The main difference is that when the time runs out, Version 1 energizes the relay and Version 2 de-energizes it. The first uses less power while the timer is running; and the second uses less power after the timer stops. Pick the one that best suits your application.
Cheap 40KHz clock
24 Second Shot Clock by Milano de Guzman
This is a circuit intended to be used in basketball shot clock.
Repeating Interval Timer by Ron J
This circuit is based on a simple asymmetric oscillator. The length of time the relay remains energized - and the length of time it remains de-energized - are set independently. With the component values shown in the diagram - both periods are adjustable from about 1 to 30 minutes.
Feedback circuit eliminates CCD-driver delay mismatch
Sequential Timer by Ron J
This circuit uses a Cmos 4017 decade counter to create a sequence of four separate events. The number of events in the sequence may be increased to nine or ten. And the length of each event is controlled independently. D13 causes the sequence to repeat continuously. If you leave out D13 - the sequence will run only once.
One Transistor timer
