Introduction: 12V Relay With Timer Switch

Picture of 12V Relay With Timer Switch

In this Instructable, we'll be learning how to use a timer switch and a 12V relay to control the extension of an Actuator. You'll be able to set the timer with up to 17 time schedules, and have the actuator extend and retract when the time is right.

No coding is required, all control comes from the timer. Any 12V power supply can be used, as long as it can deliver the current that the actuator requires (5A minimum suggested).

For this project, you will need:

- 1 x 12v Relay

- 1 x Digital Timer

- 1 x 12V battery

Step 1: Wiring the Relay

Picture of Wiring the Relay

Wiring the relay creates a half bridge. When 12V is applied to Pin 8, the relay will activate. Wiring the relay as shown will cause the voltage across Pins 5 and 6 to change from -12V to +12V. The default position of the relay is when the relay is deactivated, the active position is when Pin 8 has 12V on it. The actuator can be wired in 2 ways. One way, the default position is extended, and the timer controls retraction. The other way, the default position is retracted, and the timer controls extension. For this example we're using retracted as default and extended when the relay activates. To change the actuators position when the relay is deactivated, switch the wires on Pins 5 and 6.

Wire the relay as follows:

- Connect Pin 1 to Pin 4

- Connect Pin 4 to +12V

- Connect Pin 2 to Pin 3

- Connect Pin 3 to Pin 7

- Connect Pin 7 to GND

- Connect the two wires of the actuator to Pins 5 and 6, so when the relay is deactivated, the actuator is retracted. If the relay extends, just flip the connections on 5 and 6.

See the wiring diagram for details.

Step 2: Adding the Switch

Picture of Adding the Switch

The timer is used to control when the actuator is activated. The timer is programmed to choose which times the switch is closed. This switch is connected to the relay, choosing which times the relay is active and deactivated. By wiring the switch to 12V, the timers "ON" times will correspond to the relay being activated. If you wire the switch to GND, the timers "ON" times will control when the switch is deactivated. For this example we're setting the timer's "ON" times to correspond to the relay being activated.

First things first, you need to solder wires to the timer. It doesn't matter which direction you solder the wires, polarity doesn't matter for both the switch and the power connections.

Once the timer has wires soldered to it, it can be added to the relay as follows:

- Connect one side of power to +12V

- Connect the other side of power to GND

- Connect one side of the switch to +12V (or GND)

- Connect the other side of the switch to Pin 8

Step 3: Programming the Timer

Picture of Programming the Timer

Once everything is wired up, the actuator can be tested. Pressing the "Manual" button on the timer will simulate the timer activating. The orange light will turn on and the switch will close. This should cause the relay to activate and the actuator to extend. If not, check your wiring.

The timer has the capability to hold 17 different timing programs. This gives a huge amount of flexibility, allowing you to program many different sequences to control your actuator.

First things first, you need to program the current day and time. The timer has a small internal battery so it can go without power for a short amount of time. To be safe, assume that if it loses power you'll have to reset all the settings.

Check the annotations on the image to see which button is which:

-To program the day, hold down the clock button, and press D+ until the correct day is shown.

-To program the hour, hold down the clock button, and press H+ until the correct hour is shown (its a 24 hour clock)

-To program the minute, hold down the clock button, and press M+ until the correct minutes are shown.

-To program different timing schedules, press the P button. In the bottom left, you will see a small number (1-17) with a ON or OFF below it. When you first go through the programs, they will be set to --:--. Pressing the P button again will cycle through 1 ON, 1 OFF, 2 ON, 2 OFF... and so on.

The numbers represent the program number. When you are on the ON section of the program, you are programming the times that the switch will be closed and the relay active. When you are in the OFF section of the program, you are setting the times the switch will be open and the relay deactivated.

When you are in the program menu that you want (for example, 1 ON) you can press the D+, H+, and M+ buttons to set the times. When pressing the D+ button, the days will cycle through 15 options. Each day can be chosen, weekdays only, weekends only, everyday except X day, every 2nd day... There are many options available for all your needs.

You can press the C/R (clear/reset) button when you are in the program menu to set the values to --:-- on no days or 00:00 everyday.

When you are finished programming press the clock button to return to the current time.

Step 4: Conclusion

Picture of Conclusion

In this Instructable, we learned to connect an actuator to a timer switch to control when the actuator extends and retracts. A project idea would be connecting an actuator to a window, to open during the day, and to lock shut at night.

If you'd like to take a look at our selection of linear actuators, motions control systems and microcontrollers then please visit us at for all your actuator needs! We can even build a custom actuator or control system for you based on your own custom specifications with the help of our highly trained staff of engineers. You can learn more about the custom order process right here!

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cossiem (author)2017-01-29

i hope i am on the correct area. what i am after is a timer control from a 12volt battery in a caravan, i have a 80 watt solar panel connected to a 12 volt 110 amp leisure battery, i need to run a dehumidifier that runs on 12v or 240 v on a timer as the caravan is stored in a compound with no mains electric. i have tried to run a inverter ( 12v to 24o v ) but it runs the battery down to fast & the solar panel is not very good in the winter ( no enough sunlight)

any help would be welcome

Joenjmortgage (author)2016-06-22

I made this to open and close a deer feeder box twice daily. It worked for a month perfectly but then just stopped. I hooked the linear actuator directly to a newly charged battery and it won't move the arm. Could the actuator gotten burned out? It should be able to work with a 200lb load. It only opening a door that's less than a pound.

MasonG21 (author)Joenjmortgage 2016-11-13

Did you connect the battery BOTH WAYS? If you only used one polarity, and that happened to be the same polarity the actuator was "maxed" for, the actuator would "not work" even if it was fine.

Hi Joenmortgage,

Sorry to hear that your feeder has stopped working. When you hooked up the actuator directly to the battery, did you try connecting the actuator in the opposite polarity? If it is not moving and power is being applied, there are a few possible reasons the actuator stopped working: the gears could be stripped, the limit switches could be corroded, or the motor and switches could have burned out.

You mention that the actuator can handle a 200lb load; are you using the PA-03 actuator? It is not well suited to outdoor use, and the issue could be environmental corrosion or damage to the motor or limit switches. The actuator also could have been jammed on something, and the gears may have stripped or the motor burned out.

Please give us a call (1-800-676-6123) and we can determine the cause of failure and help you run through some diagnostics.


- Progressive Automations

MasonG21 (author)2016-11-13

I made this project, and it does work: the components and wiring diagrams produce a useful 12V actuator timer. The writing is pretty much useless, and many details are not thought out. I ended up making my own diagram showing ALL components (battery, timer, relay, actuator) as separate graphic blocks and revising to have wire junctions only at the terminals, with no more than two wires per terminal. Then I did it my way. I recommend 18# wire for most of the diagram. Why solder wires to the timer when it has 1/4" male spade terminals? I used 1/4" female spade lugs for mine and they worked great-- and they're disconnectable. The relay terminals are tiny screw-down clamps with square pads under rigid little square washers. For these connections I do recommend solder: after stripping 3/8" from the wire ends, twist the ends tightly and saturate with solder before placing them in the terminals and clamping-- makes for a cleaner, stronger, no-fuss connection.

giovine1 (author)2016-07-30

Just one question when the timer hits its time and thus powering up the actuator what stops the power from staying on and burning up the actuator

Hi giovine1,

The relay is wired so that the actuator will retract when the coil is uncharged, and extend when the coil is powered (might be the other way around depending on how the actuator is connected to pins 5 and 6). The timer is simply switching the relay on or off. In this setup, the actuator is always connected to 12V whether it is extending or retracting. The internal limit switches stop the actuator at the ends of its stroke and open the circuit, preventing the actuator from moving until the polarity of the 12V power is reversed. Hence, the only way the actuator will burn out in this configuration is if something jams the actuator before it can fully extend or retract.

Hope this answers your question.

- Progressive Automations

Ok I see that now thank you for the reply

mh2933 (author)2016-01-22

Im looking for a 12V timer/switch to turn on and off a water pump (small hydroponic system) and this seems little overkill? Do you know what Im looking for? Thanks!

MarkD258 (author)mh29332016-06-18

You don't need the actuator, that is for physically moving something like a latch on a window. You can hook this timer up directly to your pump, that's exactly what we did here:, I think you'll find this useful. It's even the same timer, BUT, I have to say that this timer is very cheap and stopped working after a few months, so I am looking at getting a more expensive/reliable one.

DanielF220 (author)2016-05-11

Can anybody help me finding same kind of relay from ebay.Not the progressive automotion because i need to get it to finland.

About This Instructable




Bio: Progressive Automations is your primary source for electric linear actuators, motion control systems and automation accessories. For over a decade, we have supplied various industries ... More »
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