Universal electronic time switch - has pulse generator supplying up-down counter and comparator delivering switching impulse when count is at zero

摘要

The pulses from a timing pulse generator are fed to the input terminals of a counter via a switch-operated interrupter. The counter uses a transmission corresp. to minutes and hours to count the pulses. The indicator shows the stage of count. The counter is an up-down counter that counts the timing pulses backwards. A counting state corresp. to the desired running time of the time switch can be set by a control element. A comparator delivers a switching impulse to operate a switching arrangement when the state of count is at nought. A memory can be provided for repeating a set running time. This time switch has wide application, e.g. for a cooking oven when the time scale is likely to be in hours and an enlarger concerned more with minutes and seconds.