Electronic timer relays are microprocessor based control devices used in time critical processes. These devices are specially designed to activate or deactivate a circuit or a system within the set time and function. This relay group, which is generally used in the control panels of power circuits, can control the system by changing the relay positions basically with or without delay.
As a function of operation, there are basically two types of time relays, delayed on pull and delayed on fall. Relays which delayed on pull are known as flat time relays and relays which delayed on release are known as reverse time relays.