General > General Technical Chat

29V Christmas lights: would like to mod with ESP32

(1/3) > >>

lezginka_kabardinka:
I just bought some tree lights (240 in a string) which run off the following adapter (photo attached), which has a built in effects selector button. I’m sure this is an “H-bridge” type, I scoped the outputs and I see PWM waves. It’s the usual 29V type.

Any idea what kind of chips drive the H-bridge in these kinda things, and whether I could tap off the required voltage to power the esp32 without any fuss with regulators etc?

My aim is to run micro python on the esp32 and have a basic http server so I can send effects commands; at the moment it’s just using a momentary button to toggle through each effect in sequence and select one.

Big Clive tore down one of these “Jutai” type adapters, but it didn’t seem to be one of these. I’m asking because I don’t wanna destroy the sealed casing without there being a good chance of it being easily modifiable.

Thanks chaps.

lezginka_kabardinka:
Final photo…

lezginka_kabardinka:
Truly the final photo actually  :D

Zero999:
Yes, they just us an H-bridge. The LEDs are connected back to back, giving two channels. The standard colour combination is red & yellow, or green & blue, but warm and cold white, are also available,which look more like gold and silver.

I wouldn't bother trying to modify it. It's probably easier to buy a 30V PSU and build your own controller. It shouldn't be difficult: an LM317L for the ESP32 and an H-bridge for the LEDs. The only thing I'm not sure of is whether the LEDs have an external resistor, or if it's build-in to the PSU.

wraper:

--- Quote from: Zero999 on December 23, 2023, 12:04:08 pm ---It shouldn't be difficult: an LM317L for the ESP32 and an H-bridge for the LEDs. The only thing I'm not sure of is whether the LEDs have an external resistor, or if it's build-in to the PSU.

--- End quote ---
ESP32 consumes too much current to do that. You need a buck converter as minimum. LEDs do have a resistor but AFAIK PSU is current limited too and drops voltage under high load rather than going into protection.

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod