Converting solar power light to constant power supply?

Thread Starter

bogey912

Joined Oct 16, 2016
32
Hello fellows. wondering if someone could provide some info for me. I bought a cheap solar powered light to put buy my back door. Its motion activated and
supposedly shuts off in the daylight. It seems to me that it doesn't actually shut off in daylight but just dims. Anyway, where I have to put it must not get enough sun because after the first couple nignt's I used it stopped working. IT has 16 LED's and is in a weatherproof enclosure so I just decided to run a wire to it and hook it up to a steady power source. It had a 3.7 volt Battery in it rated at 1000ma. To test it I cut the wires to the battery and attached the leads from my bench
power supply to the B+ and B- on the circuit board. by hooking power up here I figured I would be able to keep the motion detector circuitry in place. When I power it up this way, 3.7 volts drawing 200ma it lights up for approx 10 sec. goes dim then lights back up. It repeats this action over and over. I made sure to position it as not to activate the motion sensor part of it. Going dim in light and motion detection is not working. Anyone know what I'm missing here?
shouldn't this work as I hooked it up? Thanks for any help!
https://www.mediafire.com/folder/8t...r3tbdr,13ssiidch3qyce4,ysrte4xubxc4gpd/shared
 

ErnieM

Joined Apr 24, 2011
8,168
I would think it should work. Don't forget it will still look for darkness before the motion sensor gets enabled.
 

Thread Starter

bogey912

Joined Oct 16, 2016
32
It sort of works. It goes on and off . If I have it hooked up to to the power supply, in the dark, being real still(no motion), it just keeps coming on and off, like 10 sec. on/ 10 sec off. Being the battery is rated at 3.7 volts I would think this would be the right voltage to feed it. I have two of these. The first one I put outside, it worked a day or two, shut off when there was no motion, then nothing. Bad location, not too much sun. This second one I am trying to modify is brand new. Another thing about these is when its dark or no motion is detected, they don't shut off but just go dim. Wonder if a more expensive brand would work better?
 

Thread Starter

bogey912

Joined Oct 16, 2016
32
Anyone know of any other message boards that I can visit that might have someone on there who can answer my question? Thanks!
 

ErnieM

Joined Apr 24, 2011
8,168
I have no other forums to recommend.

Re reading your first post you state that the unit stopped working before you did any modifications to it. Perhaps you might try your tests again on a fully functional unit?
 

crutschow

Joined Mar 14, 2008
27,424
If you have the device inside, it may be turning off from its own reflected light.
Try covering the light so it doesn't illuminate the room.
 

Thread Starter

bogey912

Joined Oct 16, 2016
32
I have no other forums to recommend.

Re reading your first post you state that the unit stopped working before you did any modifications to it. Perhaps you might try your tests again on a fully functional unit?
I should of mentioned. I got two of these units and preformed the above test on a brand new one.
 

wayneh

Joined Sep 9, 2010
17,153
Yeah, I did all that.
Try a little higher supply voltage. A battery label voltage is a nominal value and is often about half way between charged and discharged. Your device may be shutting down to protect the battery from excessive discharge. A freshly charge lithium battery, nominal 3.7V, may be as high as ~4.2V. There should be no risk to your device by going up half a volt.

Also, see if you can identify how the device senses light. Covering the LEDs may not have been enough to blind it from its own light.
 

Thread Starter

bogey912

Joined Oct 16, 2016
32
Sounds to me as your psu doesn't have enough current, or the unit is self triggering from the leds.
Hello. I have a 10 amp dc power supply so current shouldn't be a problem.
"unit is self triggering from the leds.[" - don't understand what this means?
 

Dodgydave

Joined Jun 22, 2012
10,035
I mean " when the leds come on, it automatically goes off because it can see the light reflecting back" try putting solar sensor inside a black bin bag.
 

ErnieM

Joined Apr 24, 2011
8,168
Here self triggering means the LED light output is hitting whatever detects dark, so when it turns on it turns itself off, letting it turn back on it turns itself off, and so on and so on.
 

Thread Starter

bogey912

Joined Oct 16, 2016
32
Try a little higher supply voltage. A battery label voltage is a nominal value and is often about half way between charged and discharged. Your device may be shutting down to protect the battery from excessive discharge. A freshly charge lithium battery, nominal 3.7V, may be as high as ~4.2V. There should be no risk to your device by going up half a volt.

Also, see if you can identify how the device senses light. Covering the LEDs may not have been enough to blind it from its own light.
Hello. I power it up at 4.2 volts drawing 200 milliamps. I want to put this outside but instead of using the solar cell with a battery, I want to power it direct and use the motion detector and the shut off during daylight part of the circuitry. Where I want to locate this light doesn't get enough daylight
to charge the battery. Right now on my work bench The light just cycles on and off. I'm hook my power wires to B+ and B-.
Just hooked the battery backup and the solar cell. Unit still cycles on and off. IT must be either defective or a cheap piece of poop.
thanks for your help fellows!
 

wayneh

Joined Sep 9, 2010
17,153
You didn't hear us. By design the unit senses light and shuts off. Several of us suggested that you may not have isolated the sensor well enough that it cannot "see" its own light. So it turns on, sees the light, and shuts back off. It's acting as you would predict IF the sensor is not blinded somehow to feedback from the LEDs.
 

ErnieM

Joined Apr 24, 2011
8,168
As Wayne said... Also, if you removed the batteries then the solar panel may have no load so even the slightest light may be enough to trip the "I see the light" sensor.

Do you really care if it comes on in the day time? Just remove the panel, short out the connections. It made, and see if it now responds correctly.
 

Thread Starter

bogey912

Joined Oct 16, 2016
32
I heard you Way, I just don't understand exactly what you mean. I've covered the "eye" up with two pieces of black tape and it still just cycles on and off. Without any tape on the eye it just sits there and cycles on and off. By on and off I mean regular light and dim light. Excuse my ignorance:)
 

Thread Starter

bogey912

Joined Oct 16, 2016
32
Ernie, no I don't care if it comes on in the daytime. I just want this light to light up my back door so I can see the lock to put my key in.
what do you mean by "short out the connections"? I'm not sure where I would hook my 4 volts to now?
 

Dodgydave

Joined Jun 22, 2012
10,035
Ok can you post pictures of the circuit board both sides, so we can see what to bypass, or can you draw the circuit out for us?

If you just want it to come on with movement, i would use a simple pir sensor and led.
 
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