LED FLOODLIGHTS Causing flickering when switched off

[scotthayes14]

Can any one help and give me some advise please

I have a lighting circuit which as a pir sensor on, a porch light, an led outside light and a halogen outside light. I wanted to replace the oitside halogen light for another led outside light. So I did and now all the lights flicker when switched off at the switch. So I reconnected the old halogen and the flickering stopped. How can I get the flickering to stop if I want this new led light up?

 

[Marvo]

There's two possible problems, it could be that the PIR is not compatible with the LED load, it may be a solid state switch which can cause problems. Also it could be caused by a coupled or ghost voltage from a circuit that runs close to it. First thing I'd do is get the PIR out of the circuit then fix the problem using a additional snubber circuit if necessary then reconnect the PIR later once you're sure the circuit is working properly.

 

[scotthayes14]

Thanks il try that How come the halogen light stops the flickering?

 

[Marvo]

The halogen light is just a filament which needs considerable current flow to make it light up so it will allow a very small current flow without and visible light being emitted. The LED lamps take very little current to cause them to light. They usually have built-in circuitry which can over time store the very small amount of current that leaks through a solid state switch or is caused by a coupled voltage and the capacitors in the circuitry then discharge in one large pulse which causes the lamp to flash or flicker.

 

[scotthayes14]

I have taken the pir out of the circuit and it works fine. So should my next plan of action be to buy a new pir? If so what type?

 

[Darkwood]

A pir that switches an integral relay as oppose to a solid state switching and suitable for the load will be fine or any pir can be used to pull in an external contactor or suitable relay to energise the fittings.

Dont forget led fittings are inductive loads so spec your relay correctly.