Hello,
I am new to this stuff, so apologies if this is a simple to find online topic that I could just not find myself. Been searching a while now with no concrete leads.
I have a 2m length of 30LED/m APA 102 to be controlled by an Adafruit Trinket with IR input. Since this will need to fit inside a 7/8" ID pole, my thoughts are to use a single 18650 (2600mah) li-ion battery to power the whole setup (I read on the Adafruit forums that the 3.7v will work fine for the 5v strip, and I can get a 3.2v trinket to match).
My questions is what is the best way to set this up past simply connecting these (considering I will be charging the batteries outside of the device: Tenergy 2CH 18650/14500 Battery Charger w/ Li-ion 3.7V 2600mAh Batteries (4pk )- Tenergy)?
For efficiency sake, I want to connect the power to both ends of the APA102 so that the current towards the far end is not as effected by the resistance in the LED strip.
I attached a screenshot of my planned setup, and one where I attached a large capacitor (suggested on the adafruit tutorials for powering these). Am I missing anything here? Do you have any suggestions to make this safer/more efficient, or other input on this?
My thoughts are that the one battery could theoretically last 3+ hours with the right programming (low brightness/not too many LEDs on at a time). I know a person who's 128 LED device supposedly runs for ~3 hours on a single 14500 which seems insanely efficient (my guess is that hers is connected at either end of the strip too).
The bottom circuit is best but put the capacitor close up to the srtip's power connectors. You might want to put a 330R resistor in each of the two signal lines clock and data for extra safety but as you are powering everything off the same battery it is not vital.
Those things are very bright and the overall brightness control does directky control the current. I have found a value of 4 is bright enough to look at directly Andy brighter and it is hard on the eyes.
Excellent, thank you!
I should have mentioned it, but the circle on the data/clock line(s) is meant to represent resistor on each. Right now I have 100ohm, 1k and 10k resistors to use, and have been using the 1k if I remember right. Do you think any of those options will work or should I really go buy some 330ohms for any reason? I could understand if the 100ohm isnt enough and the 1k is too much for efficiency sake.
Also, if you have a recommendation for the capacitor size that would be appreciated! I have been using a 4700uf 10v from Adafruit (4700uF 10v Electrolytic Capacitor : ID 1589 : $1.95 : Adafruit Industries, Unique & fun DIY electronics and kits) on their 2.1 DC jack, but could imagine that the battery could call for a different size.
Do you think any of those options will work or should I really go buy some 330ohms for any reason?
I would use two 100R in series.
I have been using a 4700uf 10v
That is fine.
but could imagine that the battery could call for a different size.
No not really.
dfrazierj:
t inside a 7/8" ID pole
That may cause overheating problems.
Some testing with a thermometer would be wise.