LED flood light - Battery powered, light sensing
LED flood light - Battery powered, light sensing
(OP)
Hi, I'm looking to build a Pfr to Pr converter for indoor photoperiodic plants, but don't know much about electronic circuits. I plan to power a few high power Infrared LED's from rechargeable batteries. The LED's would turn on as soon as all the other lights in the room turn off for the dark cycle (12 hours), and they would slowly dim as the batteries ran out of juice (~10 minutes). When the rest of my lights turn back on for the day cycle (12 hours) I need the LED flood light to know this and begin charging the batteries again. Rinse and repeat.
IR LED:
1.6-2.0 VDC
1000mA MAX, 900mA recommended
The light doesn't have to be "bright," in any sense of the term. I plan to run two of these ~2W LED's in series.
I realize these types of lights are made, but they require a separate, synchronized timer so they can plug into an outlet, require an LED driver, and most of them are sold for exorbitant prices. The idea doesn't seem very difficult to execute if I knew a darn thing about circuit design and electronic components (I'm thinking ~$30 max).
Any and all help would be greatly appreciated.
Best Regards,
Matt
IR LED:
1.6-2.0 VDC
1000mA MAX, 900mA recommended
The light doesn't have to be "bright," in any sense of the term. I plan to run two of these ~2W LED's in series.
I realize these types of lights are made, but they require a separate, synchronized timer so they can plug into an outlet, require an LED driver, and most of them are sold for exorbitant prices. The idea doesn't seem very difficult to execute if I knew a darn thing about circuit design and electronic components (I'm thinking ~$30 max).
Any and all help would be greatly appreciated.
Best Regards,
Matt





RE: LED flood light - Battery powered, light sensing
Why not just put them on a timer?
Is the slow dimming during the dark period required (wanted) or just an unwanted artifact of your use of batteries?
RE: LED flood light - Battery powered, light sensing
The reason I figured it'd be easier to use batteries is because I can move this light source to any grow room and not have to synchronize the timer, I just plug the thing in. Similarly, if I need to change the photoperiod of the plants for any reason the IR LED's will intelligently react without any input on my end.
Is the circuit design that much more complicated when using batteries?
Thanks so much for your time, btw.
RE: LED flood light - Battery powered, light sensing
I'd stick with the timer and a wall plug. If you absolutely must have dimming, consider a slow rotation motor (like for a clock) and a circular shutter... as the disk rotates, it slowly blocks out more and more of the LEDs light.
Dan - Owner
http://www.Hi-TecDesigns.com
RE: LED flood light - Battery powered, light sensing
If you think it's not worth the hassle, though, I guess I'll just have to synchronize the timers.
Thanks again for the input.
RE: LED flood light - Battery powered, light sensing
Use a DC power supply to power a series combination of the 2 LEDs and an appropriately sized resistor to control the current. Then, also in series, place a switch of some sort - a simple PNP transistor will do. The gate of that transistor would then be biased between a Light Dependant Resistor (LDR) and a variable resistor. This will form a circuit that switches off when light strikes the sensor and on when it doesn't. It will be finicky, very inefficient and difficult to tune. To improve on that, you might need to study a bit more electronics (or buy something ready made)!
RE: LED flood light - Battery powered, light sensing
RE: LED flood light - Battery powered, light sensing
RE: LED flood light - Battery powered, light sensing
Thanks again.