Solving the mystery of the poundshop garden light which has 4 different colour LEDs all wired in parallel.
By Julian
Youtuber, shed dweller, solar charge controller aficionado
Good morning all…
Youtuber, shed dweller, solar charge controller aficionado
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Where did you find that neat chart about LEDs?
A grand exercise in triviality – and entertaining to boot! Bravo!
1) Why didn't you just spin the LED bank 180 deg. around to reverse the polarity with NO twiddling?
2) I would liked to have seen that O-scope waveform with the load UN-connected! I bet the V goes way up!
The chip with 4 legs is a solar charge controller and they are in all of these garden lights. I am sure you will look it up as I did a year ago when I was trouble shooting my garden lights.
The boost converter, making good use of the back emf that you usually dump into a diode from a relay coil.
The output is driven to 0v, to build current in the inductor, then opened so that the kick from the inductor is added to the supply voltage, repeat.
So a DC meter will only read the supply voltage
just put a lot of current through them … like ALOT :> ….. they will light up all 4
Take it apaaat….;)
Quite a neat trick. But yeah the 5252F works something like a Joule Thief… nevertheless interesting stuff
I must try 4 different color LEDs powered in pararel by QX5252. That driver supply LEDs different way. There is no constant current or voltage all the time.
ya never looked inside a solar garden light before ? and ya love ya solar power
what does "13.8v because we have a little bit of sun today mean please?
Julian, can you share a link to the document with the LED color, wavelength and voltage drop? I thought that was very useful.
Looking at the schematic, in dc current, the coil becomes a wire and is connecting you directly to the battery. The output is some type of pulsed dc, which is exactly what you said.
What is the cheapest source for blue tac or similar product?
julian, hey I got a question, or two. I'm working on a project. And I have 6v 100mah cells, and I also have 2.5v 110 mah cells, is it possible to wire the different cells together and get 6v and maintain 6v and high mah?
I have many cells, but what I'm trying to do is
I get 4 of the 2.5v and put them in series ++++- – – -, it gives me 300mah with 2.5v, then no mater how I try I can't put the 6v with them, to try and get it to 6v 300mah, I tried a diode, the regular black with grey, I was thinking mabey a shotkey might help? What do you think.
All that work, and you didn't think to disconnect the led string and reconnect it to your CC/CV PSU. You could find what voltage the leds turn on at. Would be telling to see if they all turn on at the same voltage or not.
These chip are usually made to drive one led, or several leds of the same type. Basically there's a MOSFETbetween the output and gnd pin that's switched by a 100khz square wave. When the mosfet conducts a magnetic field builds up around the inductor. When the MOSFET is open the inductor outputs a voltage to the leds. There is no capacitor nor voltage regulation. The voltage can't go much higher than the led forward voltage because the led has a very small resistance, anf it can't go lower otherwise the leds stop conduct, the circuit opens and the inductor voltage goes up.