Shocking Halloween Decoration

Sure, you could animate some Halloween lights using a microcontroller, some random number generation and some LEDs, and if the decorations are powered by AC, you could use some relays with your microcontroller. What if you don’t have that kind of time? [Gadget Addict] had some AC powered decorations that he’d previously animated with an Arduino and some relays, but this year wanted to do something quicker and simpler.

In another video, he goes over the wiring of a fluorescent starter to create a flickering effect with an incandescent light bulb. A fluorescent starter works because the current heats up a gas discharge tube which causes a bit of metal to bend and touch another, closing the circuit. A fluorescent bulb is a big enough load that the flowing current keeps the starter hot and, therefore, the circuit closed. If you wire the starter in series with a regular incandescent bulb, the starter heats up but the load isn’t big enough to keep the starter hot enough, so it cools down and the circuit breaks, which causes the starter to heat up again. This causes the bulb to flicker on and off. [Gadget Addict] uses two circuits with a fluorescent starter each wired to alternate bulbs in the decoration in order to get the effect to look a bit more random.

[Gadget Addict] goes over the dangers of using mains AC in circuits like this, and does mention that he’s not quite sure how long the starters will last – he guesses that the bulbs will burn out before the starters do. We’ve seen a couple of flickering pumpkin hacks before, but this is a quick, easy and somewhat dangerous way to get a flickering effect!

12 thoughts on “Shocking Halloween Decoration

  1. great effect

    … good thing those glass starters are contained in a sturdy (plastic?) housing.

    its my belief that the bare-glass ones may fail in a catastrophic way when abused, resulting in flying glass, at least thats what they say if you accidentally “throw em accross the incoming mains power” ;D

    do not use bare-glass starters that are found inside a sealed ballast, they are not safety rated/tested for operation outside a fixture. well, at least dont operate the bare ones outside a fixture WHILE ABUSING AND MIS-USING IT, or use protective eyewear.

    and remember any incandesant bulb could arc during failure, blowing the hell out of any control devices, like this glass device lukily contained in plastic for safety.

  2. I’m pretty sure that starters work the opposite to described in the article. They are a normally closed bi-metal strip switch. When they heat up and open this causes a rapid collapse of the magnetic field in the ballast, which causes a massive voltage spike: enough to ionise the gas in the tube. This then becomes a lower resistance path for current and bypasses the starter.

    Pretty cool hack. I love it. I might replicate this for my party.

    1. No. Both explanations are wrong.
      The starter is normally open and it is more or less in parallel to the discharge in the tube . But it is connected in series with the two electrode filaments.
      1) When you connect power, a glow discharge starts and heat up the bimetallic strip.
      2) This shorts out the discharge path of the tube and the glow discharge in the starter and puts the two filaments in series with the ballast on the mains voltage, so they can heat up.
      3) As the glow discharge is shorted out, the bimetallic strips cools and opens again. Now a voltage spike is induced in the choke which starts the tube if you are lucky.
      3a) If not, got to 1) and repeat
      4) The discharge voltage of the tube is lower than the starter, so once the tube has struck, the starter will remain cold and open.

  3. The seventies called. They want their poor man’s fluorescent starter flickering disco lights back.

    Honestly, this was a well known cheap hack back then, for people that couldn’t afford real disco lights for their party room.

    Nowadays, we have microcontrollers with WiFi, and LED strips.

    1. Well it was a well know cheap hack to stick a piece of ginger in a horse’s asshole to make him run a race faster, but if you weren’t around a 19th century racetrack you’ed never know would you. Old tricks to you may be new tricks to others.

  4. They last quite a while. Mine are still working after a year. I run them for 2 hours a night for a couple weeks. I crammed mine into a extra deep single gang box and put a receptacle on the front.

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