What Is a Timer Relay?

timer relay

What Is a Timer Relay?

Time delay relays have one main function: to delay the closing of electrical contacts. Their timing range can vary from a few seconds to hours and days.

When choosing a particular delay relay, it is essential to consider its delay mode and delay accuracy in accordance with control requirements. This will ensure that the control circuit fulfills its objectives.


Time delay relays are used to control the switching of loads through a set time after the initial application of power. They are able to switch the load either on or off and are commonly used in lighting, air conditioning, or electrical distribution high side gate driver systems. They differ from normal relays because they introduce a timing element and control the initial triggering of the relay by allowing for a controlled delay before the output contacts change state. There are several types of timing functions including interval, off-delay, on-delay, one-shot, and programmable (multifunction).

When the timer module is triggered it will energize the coil for a period of time that is preset by the user. This duration of energization is known as the accumulated time. After the accumulated time has passed the output contacts will change states; normally open contacts will close and closed contacts will open. The output will remain in the changed state until power is removed from the coil or a reset occurs.

Most times delay relays have a large dial that allows the user to adjust the duration of the accumulated time, a smaller control switch to select the timing mode, and another small switch that can be used to set the time base between sec, min, or hrs. This is a simple way to set the desired delay and is easy to read due to the large number of markings on the dial.


The timer relay is a small device that can be used to control the operations of electrical circuits. It is a 8-pin device that works on the principle of changing the state of the common ends depending on the time setting. Each common end has normally closed and normally open options. When the commons are energized through power, they stay in that state for the set time and then come back to their original position.

Relays perform a crucial function within any electronic system. They allow one level of current or voltage to control another level, even if the two levels are different. This allows the control circuits to work independently of the power wiring. This is especially important when dealing with safety circuits and can prevent fires, explosions, or other dangerous conditions.

There are various types of timer relays available. Some have multiple modes with programmable timing functions, while others are single-function devices. There are also different input voltage and output options. These factors are important to consider when selecting a relay for your project.

The simplest type of timer relay is the repeat cycle timer. These devices energize and de-energize the actuator at regular intervals. They are commonly used in HVAC systems to operate the compressor for a certain period of time once the thermostat is activated. This also helps to save energy by avoiding overheating of the compressor.


A relay with a timer allows you to control the flow of electricity through an outlet. This can be used for things like turning lights on and off, or even allowing your refrigerator to turn off after it has finished charging/powering whatever is plugged into the outlet. It works by sending an electric signal through the “on” coil and pulling in an armature to activate it. When the “off” coil is triggered, it pulls in the opposite direction and no longer allows electricity to flow.

A common use for timer relays is to operate fan & motor controls within AC systems to ensure that the blower motor doesn’t come on until after an optimum amount of time has elapsed. Other applications include operating door locks that should wait a certain amount of time before they actually lock, elevator door control & gas valve controls.

Time delay relays come in several different forms, including on-delay, off-delay, single shot and repeat cycle. They can also be either manual or automatic and can be adjusted for multiple settings. Some can also be programmed for specific timing schedules through a button on the front of the unit, while others need to be manually triggered and deactivated each time the circuit is triggered. For more detailed information on handling a particular model of timer relay, please refer to its PINOUT explanation, Operating modes and LED Indications.


A time delay relay is a handy piece of equipment that allows you to control electricity-powered machines with delayed activation or deactivation. These are often used in high-performance applications like robotics or machinery that require precise timing operations. They can also be used in more everyday settings such as controlling the timer on a coffee maker, automatic door openers or the lighting systems in airports and train stations.

These devices have a very simple working principle, as shown in the diagram below. When voltage is applied to the input terminals of the relay, Logic Comparators current flows through the coil and closes it. This energizes the output, which in turn activates or deactivates the load connected to it. Once the preset amount of time has elapsed, the switch opens and de-energizes the output, returning it to its initial state.

There are many types of timer relays, each with different functions. The most common is the on-delay timer, which starts when a control signal is applied to its trigger pin and stops when the desired amount of time has elapsed. Other types include interval-on-operate, flasher and repeat cycle timers.

These relays are easily programmed using a push button interface, which makes them very versatile for almost any application. When the program button is pressed, a menu will appear which lets you choose from 15 different days of operation (weekdays only, no weekdays, every day, everyday except x day or every 2nd day). Once a day has been selected, simply press the SET button and your new program will be active.

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