After buying a rather lifeless LED Christmas tree from the pound shop, I thought I'd liven things up with an LED flasher circuit. There are lots of different ways to flash an LED, from a single unijunction transistor all the way up to a PIC microcontroller. I've chosen a slightly odd circuit which uses one transistor and an LDR (light dependent resistor).
Inspiration came from here: http://www.b-kainka.de/bastel29.htm

By Julian

Youtuber, shed dweller, solar charge controller aficionado

12 thoughts on “Pound shop xmas tree hack: one transistor led flasher with ldr”
  1. Avataaar/Circle Created with python_avatars Ross Anderson says:

    I know this is old but…I'm trying to see how you connected the trim pot. There's no clear indication as to how its connected. I tried to duplicate the circuit but couldn't get it to work. The link isn't much help either. Can you provide a schematic for it? Thanks

  2. Avataaar/Circle Created with python_avatars Readme .txt says:

    People who use NE555, LM555 or Microcontrollers just to flash LEDs should be locked in prison or at leat some mental institution.

  3. Avataaar/Circle Created with python_avatars BLOODjack143 says:

    can i use an optoisolater will it work?

  4. Avataaar/Circle Created with python_avatars karen berry says:

    Great tutorial Julian 🙂

  5. Avataaar/Circle Created with python_avatars Mark d says:

    Nice hack. Crazy how it only cost £1.
    World is full of cheap unnecessary junk.
    Nice little hack though. Can I have it? 👍🏻

  6. Avataaar/Circle Created with python_avatars gewema says:

    Ok Julian…after seeing this fabulous Xmas tree with the beautiful LED licht…i am going to built one myself and with the whole Family sitting all around this tree we are celibrating Christmas …..HoHoHo !!!   🙂  tnx for all the video,s this year ..merry Christmas and a happy New Year !!!  greetings from Holland.. 73 Gerben PA0GDW

  7. Avataaar/Circle Created with python_avatars NASA THE POTATO says:

    Very nice

  8. Avataaar/Circle Created with python_avatars douro20 says:

    How long have you been a computer programmer?

  9. Avataaar/Circle Created with python_avatars Mirko Mueller says:

    LOL – Pimp a x-mas Tree. Well done !

  10. Avataaar/Circle Created with python_avatars ToddFun says:

    Could have been simpler with a self-flashing LED. Search eBay for:
    50pcs 5mm Red Diffused Round Self Flash Flashing LED Blink Bright Leds
    or better yet
    20pcs, 5mm Diffused RGB Rainbow Slow Flashing Flash Red Green Blue LED

  11. Avataaar/Circle Created with python_avatars iceberg789 says:

    when opening did not mean tearing it apart …..

  12. Avataaar/Circle Created with python_avatars Chris Leech says:

    Nice to have such a ready supply of parts to work with. I am still building my kit, and there seems no end to the parts I might order 🙂

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