Xenon strobe query

[coopersim]

Hi,

I have a xenon strobe that I've wired to my electric gate, unfortunately the polarity on the motor is reversed when the gate is closing, and the strobe doesn't work.

Is there a relay or similar that can correct this so the strobe has the correct polarity regardless of the direction of travel?

Thanks

 

[Deryck Tintagel]

What voltage? 240VAC or 12VDC? I would use a bridge rectifier but not without some protection on a mains supply

 

[coopersim]

Sorry! It's 24v DC

 

[EightyTwo]

Check that there isn't a beacon output on your gate controller before you jury-rig a bridge rectifier across the motor drive... Usually, you want the strobe to start flassing before the gate motor starts. Also, if the motor starts slow, speeds up and then slows down at the end, you'll find that it won't be 24V all the time. Make sure that the controller isn't measuring the motor current to detect any obstacles.

 

[coopersim]

There is a beacon output but it's pulsed

 

[SimonH2]

Delay off timer triggered by the pulsed output ?

 

[Europlex]

There is a beacon output but it's pulsed

Then don't use a strobe.

 

[SimonH2]

Or use the pulse to trigger the strobe. Though that does then leave the issue of how to make the strobe power up before the pulses start and power down afterwards.

 

[coopersim]

The beacon doesn't power up before or after the gate moves anyway

I'm not using a beacon because two led strobes have burnt out and the original car brake light style bulb causes the motors to slow when illuminated.

 

[bernardgreen]

Take the motor supply to the coil of a relay. Use the contacts of that relay to control the operation of a lamp strobe or whatever fed from a suitable power supply.

As to the strobe not operating before the gate starts to move. I am sure that regulations now require that if a strobe is fitted it should start to oeprate before the gate starts to move.
Safety requirements for power operated gates have tightened up in recent years following two deaths where gates have crushed people.

 

[SimonH2]

A quick search comes up with these links :
Door and Hardware Federation "Guide to gate safety legislation and standards" which makes no mention of warning lights at all.
This installer page does say "We can fit gates with warning lights that illuminate when the gate area is about to be violated and cautions people nearby that the gate is about to open."

But my quick search doesn't come up with anything really regarding warning lights - I suspect they aren't required for gates in public areas on the grounds that you can't assume "the public" are well enough trained to take any notice of them, and the gate needs to be inherently safe through other means. Ie, you can't assume that a 5 or 6 year old (the ages of the ones killed IIRC) child will see warning light and stay out of the way - so you have to assume that sooner or later one of them will get in the way so the gate needs to be designed and maintained not to hurt them (either detect their presence and stop without contact, or detect the movement restriction after contact and back off).

 

[coopersim]

I already have in place a set of detectors and at no point is there a situation where someone could become trapped between a gate and another object without breaking the beam on the sensor. I was under the impression that visual aids were mandated for all electric automatic gates.

 

[bernardgreen]

My understanding ( from research on automating my gates ) is that warning lights are not compulsory but if they are fitted they should ( must ) start operating before the gate starts to move.

 

[sparkymarka]

What make are the gates ? Most have an output for a flashing light

 

[coopersim]

mHouse

Yes there is an output, but it's pulsed and I've blown two LED units already as the voltage is an odd 15 or so volts