LED lamp. With PIR switching......

[Stilldrillin]

I have been updating my garden/ patio lights, with LED corn lamps.....
 Had, no problem, at all. With the dusk/ dawn, photocell lamps.

But. The PIR, drive approach lamp, insists on glowing. When it should be off..... 




I googled the problem.
 It's caused by the switching, needing a low power feed, passing through the bulb.
This is not noticed by 60watt bulbs. But the 9w lamp glows, during the day.

It was suggested, a 220v neon indicator light across the bulb terminals, would cure the problem. 

Nah! .. Now, both of them glow, dimly......




And, brightly, at night.......




Now.... I understand, there is no, actual problem. But it annoys me, as it is not, right......


Has anyone got a better, simple idea? 

[AdeV]

Better? Sure....

Simpler? I'm really the wrong person to ask 

Have you got an Arduino and a relay handy? 

[Stilldrillin]

Have you got an Arduino and a relay handy? 

In a word, Ade. No! 

But. I've got a spare, red indicator light! 

[AdeV]

Have you got an Arduino and a relay handy? 

In a word, Ade. No! 

But. I've got a spare, red indicator light! 

So - the problem is the current going through the light constantly? If so, I wonder if you could put a transistor/resistor circuit in there somewhere, such that the power required by the PIR flows to it all the time, but power only goes to the light if the PIR is triggered.

I don't know much about PIRs - specifically, I don't know how they switch - so I don't know if it's something you could easily tweak so it actually worked as a proper switch, rather than (as seems to be the case) a low/high resistor.

[ddmckee54]

You've found out that there's leakage current through the switching circuit, and you've also found out that leakage current is not a problem with a big honkin' load like a 60W incandescent bulb.  You need to put in a pull-down resister, something that will reduce the leakage voltage to effectively zero, yet not be fried when the lights are turned on.  Remember not to exceed the wattage rating of the resistor since it's going to have current flowing through it 24/7.

I've been bit in the butt by this one before, and with a well respected electrical manufacturer.  I did a project a long time ago where I had to install several brand new itty-bitty relays in an ancient control system.  The new PLC turned them on just fine, but there was enough leakage current in the PLC output module that the relays never turned off, itty-bitty relays remember?  The leakage current wasn't enough to turn the relay on initially, but it was enough to keep it on once the PLC output turned off.  A 10K pull-down resistor across the relay coil terminals and the problem was solved.

Don

[fcheslop]

Hi David, recently replaced some outside lights and had the same problem .Replaced the PIR and the problem was gone
Any decent wholesaler CEF City Elect should be able to sell you one for much cheapness and advise
Its a while since I played with the magic blue spark stuff and remember on the older PIR units they passed a wee bit of current when switched off just cannot remember the name of the dew dew thingy that does the switching thyrister??? or something like that
The good thing is I no longer need to remember
cheers   

[Stilldrillin]

Thanks for your replies.

Frazer's reply set me thinking.

The PIR, was originally mounted on a 500w floodlight. Around 30+ years ago! 

Modern switches use 0.1w, when static. I guess, mine will use much more!

 https://www.ebay.co.uk/itm/Outdoor-180-Degree-Security-PIR-Motion-Movement-Sensor-Detector-Switch-2-Colors/282483617390?hash=item41c555ee6e:m:m-5IVl69mGXbeofa68oamqg:rk:2:pf:1&frcectupt=true

Time to risk a new switch, I think..... 

[Stilldrillin]

Problem solved! 

I thought, I already had a spare PIR. High up, on the top of the workshop cupboard.....
 Unfortunately, I've recently had a new roof installed. The shop area is a complete and total TIP.
After a thorough search. I ordered one from ebay. £5.99. 

The following morning. It was on the front of the workbench, in plain view!! Obviously, put there overnight by the shop gnome..... 

According to the receipt, I paid £8.99 for it. In 2004......

I'm pleased to say. The 15yr old, new switch, is working perfectly...... 


And..... I still have a spare......