Light Sensor.

Is the sensor the correct, North American, voltage?

I did not check, but I believe it is as I purchased it at Home Depot

What happens when a filament bulb is substituted for the compact fluorescent?

The filament bulb does not flicker. If you look at it closley you can see that it does but nothing anyone would notice.

If the sensor is presently set to an European voltage setting of 220-230VAC, should the facility exist on it, then changeover to the North American 110-120VAC setting might be all that is necessary.

If the facility does not exist, among the possibilities is that the sensor's electronics are producing half-wave-rectified DC instead of AC. If this is so then it could be faulty, and one of the causes could be a duff semiconductor in the output circuit of the device. If it has been purchased retail, one option is to take it back to the store with receipt and a rig that can demonstrate the perceived problem with it in circuit and the lack of it without, and ask for a replacement under the store's product warranty. While there, check the replacement sensor at the store in front of the staff before departing. If the problem persists no matter which of several sensors it tried, then it probably indicates incompatibility between the electronics in the sensor and the electronics in the fluorescent lamp. In which case, substituting either of them might make the problem go away, though cause a loss in desirable function. Should this be unacceptable, then inserting a relay between the sensor and the lamp would be a 'technical fix': the sensor turns on the relay and the switch on the relay feeds the supply upstream of the sensor to the lamp; some construction work might be involved and there is no assurance that the relay will not buzz when connected to the sensor. Alternatively a refund might be appropriate.

Dear PeterR:

How ever your information about light sensor you are using for your house is not complete. But I suggest you may not be electrical engineer too. So I advice you to do the followings:

1: If your light sensor is activating a magnetic switch in this case there may be the following possibilities which causes your light to flicker:

a: Your sensor is not protected properly from the light of your house. Or it may be directed to the moon light. In these cases it is required to change the sensor to a new one not to be effected by these lights.

b: May be the voltage of your line is low such that it can not activate the magnetic switch properly thus causing the contacts to heat up quickly and cause the flickering.

c: The voltage of the main line will be flickering too.

2: May be your sensor is activating another SCR. In this case:

a: There may be some lose connection in the switching circuit.

b: Or The above problems of the sensors may exist.

c: The SCR used as switching element is defected.

Agreed. All good possibilities.

Most likely, the light sensor uses a solid state switch, probably a thyristor such as an SCR or a triac, which needs a certain amount of forward current in order to maintain current flow through it after the sensor gates it on. But because the CFL uses a switch mode power supply that draws current in small non-linear "chunks", there is not enough initial current to maintain the thyristor flow after the sensor stops gating, so it turns off. But the sensor pulses it's gate again since it sees that there is no flow, and this repeats ad infinitum as a flicker. This then is essentially an inherent design flaw of the sensor in that it did not take this into consideration; not uncommon with the cheap knock-off products coming from China into places like Home Despot. Whoever designed it left out critical circuitry, probably to keep it cheap and small (which also translates to cheap).

If you could disassemble the sensor and get to the circuit, you could add a dropping resistor that will represent a slight additional load once the unit turns on, but that will also mean heat, which the unit may not be designed for (otherwise it would have been there). You only alternative is to either replace the sensor with one that says it is capable of controlling CFLs, or use the sensor to turn on a relay, then use the relay to turn on the CLF.

Drat too late...

Will have to resort to bad joke to save face....

Suggest heavy sensor may be more reliable...

Double Drat...insufficient humour quotient...

I shall go hide in one of my secret places (if you need me I'm under the car)

http://en.wikipedia.org/wiki/Drat%21_The_Cat%21

Nice poster!

Check you mounting of the sensor. Is the light from your bulb reflecting back to the sensor and trying to turn it off? Is there another light coming from somewhere interfering with it's operation. Is the sensor defective?

I offer these since other have touched on the obvious ones.

Did you make the Power Puff Girls. And if so, Can I buy some factor-X?

I recently bought a photo cell for the same purpose. I noticed that many of the electronic timers and so on specifically stated "not for use with compact fluorescent bulbs", presumably because of the ballast requirements. I did find one that was suitable for all lighting types, and even electric motors. It's switching 6 CFLs on my garage and works fine.

I know this question has been asked about CFLs before, but what is worse...

• Saving lots of carbon from going into the atmosphere?
• Dumping a major annual increase of mercury into landfills, whose contents usually wind up in waterways?

I know global warming is bad, but I'd rather be hot than crippled and insane!!!

I think the CFLs are the way to go, but with a return value on them (I forget what Pfand is in English, sorry!), so that they have to be returned for cash back when they go wrong.

As you fully and correctly point out, they must not land in the rubbish!!!

Let us hope that a less poisonous version will soon be available....

Same problem:- I am appalled at just how many European countries do not require that all batteries be "returned to sender" either.....

usually when you like to control a light circuit(s) thru a photo cell, it should be done thru a contactor, so your photo cell is controlling the coil of the contactor and not the line of it.

Good Luck

Fadi.

You should use a small (5-15W) bulb parallel with the fluorescent one in order to ensure the necessary minimal (Ohmic) load.

Dear peter,

My name is rishi and you can contact me at rishi_rajpoot@yahoo.co.in

I think your problem is related to the noise pickup,I have a good experience on light sensors and i therefore observe that most of the sensors used, pickup some additional signals as 50 or 60Hz line freq. etc,i think if you use a normal light bulb in your project,then your problem is solved because fluroscent tubes produces fluctuating fields....

Ur unknown friend

Thanks for the help guys. I changed the bulb to a florescent bulb and it has been working since. I will look at the sensor and determine if it is ok for use with a compact florescent.

The perfect and to my mind only correct answer. Exactly the problems I had to fix years ago when designing a system for a large line printer, it got to much 50 HZ pickup from Fluorescent lighting.

And of course 60HZ will be no better!!!

The Tungsten filament lamp does not respond as quickly to the varying AC voltage, so the problem is much less apparent.

You could design a filter, or increase the time constant of your light sensor, but quite often, increasing the values of a few caps to keep the Triac fully turned on will get rid of the problem....

By the way, the Triacs in commercial units are sometimes NOT beefy enough to handle the starting current of CFLs, they blow within a few weeks of usage!!

Is the flickering random or constant? If constant, is it like when a PC monitor's scan rate is set too low - kind of a shimmering?

Yes the flickering is constant