‘Driverless’ rgb floodlight from aliexpress

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‘Driverless’ rgb floodlight from aliexpress

#1 Post by Rub87 » 16 Dec 2020, 20:53


Ive bought a few 50W RGB floodlights from Aliexpress. They were advertised for 100W but yes, for 20 euro even 50w is nice.

Opened them up. They are a pretty cool design. There is no switched power supply like 99.9% of all other leds. Instead it uses just a rectifier and enough leds in series. So theoretically it will not fail as easy as all other china floodlights with ubercheap and crappy driver modules.
Each color pulles approx 70 mA, with 233v mains this nets 49va. Im unsure what the power factor is but lets assume they are 50W items.

It is controlled by a unmarked sop8 IC, which handles the pwm for the 3 colors, eeprom and infrared input from the remote. I want to control a number of these with an esp so ideally the most easy and clean way would be to mimic the remotes infrared signal and feed it with an optocoupler to the unmarked ics infrared input pin. Because I cannot code this I will use a ps2502-4 per light controlled by a pca9685 controlled by an ESP and remove the stock IC. Stock IC Vcc is 4.0v. The drivers go live when grounding the pin going to the sop8 ic via a 10k resistor. With the sop8 chip removed the leds are on a few % and when measuring with a multimeter they flash. Therefore I added a 1k pull up resistor to the +4v to turn them firmly off. The darlington array in the ps2502’s will pull the drivers input down via the 10k resistor.

I used a ps2502 per light to be sure that if the L and N supply would be switched it would not burn the drivers.
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Re: ‘Driverless’ rgb floodlight from aliexpress

#2 Post by TD-er » 16 Dec 2020, 23:05

Just one question that immediately comes to mind.
What will happen if the LED of the optocoupler stays on (e.g. the controller no longer sends a PWM, but remains in 1 state) ?
Will these relatively high power LEDs keep burning at max. power?

Not sure if they are designed to do so.

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Re: ‘Driverless’ rgb floodlight from aliexpress

#3 Post by Rub87 » 17 Dec 2020, 00:03

The leds are designed to stay on 100% duty yes. the amount of leds and series resistors onboard balance each color at 70 mA. I am unsure what the led type is but I measured this with the factory fitted controller at full brightness per color and all 3 they were 69.x mA. withe gave around 210 mA. with the drivers 'manually'' grounded I got the same current

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