Electric Gates and IR Sensors

[JimboM]

Hi guys

Sorry know this isn't alarm related but thought this was the closest forum that might be able to help.

We have a set of electric gates across our drive that have safety IR beams either side of them. Recently the ones in front of the gate have been playing up in the mornings and it would appear it's because the sun is hitting the beam and washing it out. So once the gates have opened they will not shut as they think there is something in the way. I've tried adjusting the angle of units slightly but can't find a reliable position, nor does trying to shield the units themselves seem to work so can anyone recommend an alternative unit that would be a direct replacement but have a stronger beam?

These are the ones we currently have
http://www.ebay.co.uk/itm/140402566...IT&clk_rvr_id=869713148022&afsrc=1&rmvSB=true



Would these possibly be a better alternative

http://www.amazon.co.uk/cameras/dp/B008X0VPVW/ref=cm_cd_ql_qh_dp_t

Would the double beam be better than the current single or is it likely to cause more issues? Also are IR sensors all pretty much the same wiring wise or do specific makes have their own confguration. ie are these likely to be a direct swap



Thanks

 

[sparkymarka]

Are you sure it's the sun ? Have you tried bypassing the beams on temporary basis to make sure this is the issue ?

 

[JimboM]

Yes, it's definitely the sunlight, only happens in the morning when the sun is that side of the house and if I pull my car up right across the gate entrance so that the 'beam' is in the shadow of the car the gates will then shut.

 

[EightyTwo]

Is the cover clean? If so, then the beam is a crappy design! Can you swap the transmitter and receiver over? Then you might find that it doesn't work in the evening!

 

[JimboM]

Both cover's clean so am hoping it's just a crap design and why I was looking at alternatives to swap them out. To be fair the angle and position of the sun in the mornings does mean it's shining directly at the sender unit so can see why it struggles. I have tried a temporary shield around it but that didn't help.

Can't swap the units around as the sender only has 2 wires but receiver has four and not digging up the drive to get to the buried cables.

 

[bernardgreen]

This might seem counter productive but adding an extra layer of IR filter may solve the problem by cutting down the amount of visible light and infra red reaching the elements.

The most common failure mode is when visible light saturates the sensor making it unable to receive the signal from the TX

The system should be using pulsed or modulated IR ( infra red ) and the receiver is looking for that modulation among the un-modulater IR it receives from sun, lights, people and other heat sources. If the receiver element is saturated with IR from other sources it will not be able to receive the modulated IR. Reducing the amount of IR will ( should ) remove the saturation and although the modulated IR from the TX is reduced the now un-saturated receiver may still be able to detect it.

it's shining directly at the sender unit so can see why it struggles

That is strange.

It might be that the TX element is being overheated by the sun and it's driver is shutting down or the TX element is "reflecting" a lot of the sun's IR towards the receiver and thus suaturating it.

 

[sparkymarka]

The nice photocell have a habit of burning out when connected to some nice control boards the supply goes from 24 v to 50v and overheats the photocells , worth checking what voltage is at the photocell

 

[Muawiah]

My advice is to swap tx and rx places put the receiver on the opposite side
If you did not get a result then use reflector type sensor where the transmitter and receiver in a shaded place