Any electricians here?

[kota]

So my place have a garden light that is connected to a light senor, I have not used it for a LONG time, and when I tried it recently, it took a few flips on the switch before the light came on, so I changed the bulb, same problem. So I tightened the wire connections, cleaned the sensor element and covered it completely so that I can test it during the day.

I noticed that the light works, but it just has a +/- 20 seconds delay before the bulb actually comes on, the weird thing is that once I left the light on for awhile, then switch off and immediately switch it back on, then there will be no time delay. But if I left the switch off for a few minutes then switch on, then there will be a roughly 20 seconds delay again. I have also changed the light switch just in case it was some kind of wear and tear, but same problem. This problem feels as if the circuit takes 20 seconds to energize during initial startup or something which baffles me.

I cannot remember that this 20 seconds delay was always there, but maybe I remembered wrong, is it possible that the light sensor is causing the delay? Looks like some wires were spliced to connect to the sensor instead of just a simple screw on, so I have not tried to remove it. Or is there a more logical reason for the delay that perhaps I just missed completely?

Thanks!

 

[myBBexpert]

Does the light have a transformer or control gear?

 

[Jet-Fighter7700]

is the Bulb a CFL or a regular bulb?

 

[ChuckMeFarley]

Not an electrician, Depending on the internal circuitry, you could be looking at a few possibilities. Defective PIR sensor or internal transistor/mosfet/relay. My guess would be a relay of some sort struggling to energize the coil side and close the contact side. Also, some of those sensors had delay, sensitivity and duration pots for adjustment, does it?

 

[kota]

is the Bulb a CFL or a regular bulb?

I tried both incandescent and LED bulbs, they yield similar delay time.

 

[kota]

Not an electrician, Depending on the internal circuitry, you could be looking at a few possibilities. Defective PIR sensor or internal transistor/mosfet/relay. My guess would be a relay of some sort struggling to energize the coil side and close the contact side. Also, some of those sensors had delay, sensitivity and duration pots for adjustment, does it?

Unfortunately I do not see any places for adjustment, that thing looked more like a circuit board (with housing) that is attached to a light sensor. Not even sure where the previous guy got it from, don't find something similar on google.

 

[RonSwanson]

Not an electrician, but that behaviour is common for PIR / day/night switch circuitry.

Let's get an electrician to confirm: @soulie

 

[soulie]

Not an electrician, but that behaviour is common for PIR / day/night switch circuitry.

Let's get an electrician to confirm: @soulie

common .most take a while to switch on and lots have a delay off so if you shine a light on it it won't drop the relay in for say 20 seconds .relay must be energised during the day and be released at night so if faulty the light will stay on but lots dont work like that especially the chinese ones .some plug into a base and some are hardwired .

 

[DapperDanMan]

Defective PIR sensor

Or perhaps @kota is just not hot anymore?

 

[upup]

Pic of your night switch. It will be your problem.

 

[RonSwanson]

common .most take a while to switch on and lots have a delay off so if you shine a light on it it won't drop the relay in for say 20 seconds .relay must be energised during the day and be released at night so if faulty the light will stay on but lots dont work like that especially the chinese ones .some plug into a base and some are hardwired .

Mine are just like that, pretty temperamental. And if you want even more fun, wire 10x Chinese LED security lights with PIRs in series, they set one another off at the wierdest times. Sometimes it's dependent of the humidity, other times the temperature, sometimes just the air pressure fluctuations. On PIR models, "fine-tuning" the three potentiometers can drive one crazy, especially when they are mounted high up and you have get the ladder out every time

 

[kota]

I have tested it last night as well, doesn't seem to switch off itself or flickers, so it seems to be working just fine, only with that 20 seconds delay, and it sounds like it could be a characteristic of these sensors, so I am just gonna leave it and live with the quirk. Thanks for all the inputs peeps!

 

[upup]

I have tested it last night as well, doesn't seem to switch off itself or flickers, so it seems to be working just fine, only with that 20 seconds delay, and it sounds like it could be a characteristic of these sensors, so I am just gonna leave it and live with the quirk. Thanks for all the inputs peeps!

That device use a very cheap power supply, so that time it stays on, it takes a cap to charge up.