"Double, double toil and trouble; Fire burn and cauldron bubble. Fillet of a fenny snake, In the cauldron boil and bake."
Macbeth
Bill Shakespeare
For a school drama production where three "witches" dance around a cauldron, we needed a way of lighting the base of the cauldron in a semi-realistic way without burning any students (which would be way too much paperwork). We have recently received some "flasher" LEDs from 中国 which were bought for a jewellery project (more on that in a later blog), and might be of use in this instance. Also we have a few ESP-8266 modules around, including the Nodemcu development board, so that we can activate the lights remotely via WiFi.
The ESP-8266 does not have the voltage (3.3V) or the current (12mA) to drive the flasher LED, so first we have connection via a small resistor to the base of our old friend the SS8050 NPN transistor. Now that the flasher is running (9V), we can draw it's signal to the base of another transistor, and this time it is a 2SC2655 which can continuously draw 2A from the collector. That should be enough to then to run an LED strip (also 9V, but rated at 12V) and the strip should "misfire" using the signal of the flashing LED. Let's go!
First draw out the circuit diagram
A little neater via EasyEDA
Prototype and test
The PCB soldered up in a box
Wiring underneath
In a neat(-ish) box ready to be deployed
The result is a great faux fire, but sorry for the crappy video from the new phone (still learning)...
In the meantime some weird carrot god has been messing with our garden and the result is not very pretty! Let's hope the goats like mutant carrots.
Supermarket ready? Yikes!!
Take care y'all and come back and visit again sometime.
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