Everything you need to know about electric gate sensors


You’d be hard pressed to deny that the technology behind electric gate automation really is impressive. In these systems, remote transmitters, access control systems, keypads and proximity readers all work in perfect harmony to protect your home and make sure access to your property is swift and efficient. Arguably, electric gate sensors in the form of photocells are the most important part of the technology involved in electric gate automation, partially because they ensure your car doesn’t end up with any nasty scratches. Most importantly though, they keep everyone safe! Here’s everything you need to know about how they work.

1) Pairs of sensors form a connection

Each electric gate comes with its own pair of photocells. These cells are extremely important. They sit across from each other (with one on each gate post) and an infrared beam is sent from one to the other. One of these photocells is known as the ‘transmitter’ because it sends the beam to the other cell, while the second cell is the ‘receiver’ because it detects the presence of the beam.

While this infrared beam remains unbroken, the photocells know that the path is clear. However, if the beam is broken, then the photocells know that there is an obstruction in the way of a closing gate.

When this happens, such as when a car drives towards a closing gate, the gate changes direction and opens so the car can pass through. This stops the gate from colliding with the car, potentially causing damage or injury.

2) Sometimes, two pairs are better than one

For safety purposes, you only really need one set of photocells on the outside of the gate. However, if you’re looking for maximum convenience, then it’s well worth considering having a second pair of photocells fitted to some mounting points on the inside of your gate.

This way, an incoming vehicle will break the first beam as it enters the property, and then break the second beam as it moves through the gap. In this system, the gate will only start to close when both beams have been established again and a suitable amount of time has passed (usually a few seconds).

Alternatively, if the gate is closing when a vehicle approaches from the inside, then the gate will open once again and allow the car to pass through.

3) Cell positioning is vital

In order to work correctly, cells need to be fitted at the correct height and be aligned properly. Generally, photocells will be positioned at around a height of 600mm from the ground in a post or column. This height is very important. Any lower, and the beam may pass below a taller vehicle like a 4×4. Any higher, and it may pass through the window of a low sports car.

4) Blocked photocells will stop your gates moving

If the connection between your two photocells is blocked, then your gate will stay open. This is really important as a safety feature, but if your gates are stuck open and you can’t see anything obvious in the way, then you should also check your photocells closely. Something as simple as a leaf or a piece of debris blocking the path of the infrared beam will cause the connection to break and will keep the gates open.

5) Photocells should never be used for access

Now, this is quite an important bit. Photocell pairs only work when a gate is in a command operation. That means they’re not suitable for providing a method of entry and exit.

Plus, even if you could open the gate while you walked past on your way to the shop, it would also be possible for pets and intruders alike to open the gate and undermine all the security benefits your electric gate provides. For this reason, a push-to-exit button or a vehicle detection ground loop are both better options for access purposes.

At Gate Auto, we have over 30 years of experience in supplying and fitting high-quality gate automation. We provide a wide range of electric gate kits and garage door openers alongside an array of accessories to ensure you get the most out of your investment. Feel free to browse them right here on our site, or give us a call on 01282 677300!