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Project Notes

#757 Wobbly Wind Bell Kit

Building the Wobbly Wind Bell demonstrating a simple RC oscillator circuit. Available as a cheap project kit from many online sellers.

Build

Here’s a quick demo..

clip

Notes

The Kit

The Wobbly Wind Bell Kit is available from many sellers on aliexpress

kit_parts

Packing List

Qty Refs Description
80   Blue LED 3mm
5   Green LED 3mm
10   Red LED 3mm
25   50Ω resistor
3   150kΩ resistor
2   10µF electrolytic capacitor
2   S9013 NPN Transistor
1   STDP switch
1   3.5mm power jack
1   USB to 3.5mm power cable
1   PCB

Circuit Design

The circuit uses a simple oscillator to switch between two banks of LEDs. The circuit is similar to that demonstrated in LEAP#049 BJT RC Oscillator.

PCB layout:

kit_pcb

Here’s a quick redraw of the circuit in Fritzing:

bb

schematic

Build Log

After initial construction, quite a number of the LEDs failed. It seems that the components provided in the kit were not good quality.

test01a test01b

After replacing the failed LEDs with components from stock, all is working correctly:

build02a build02b

The completed board:

build01a

Credits and References

About LEAP#757 BJTRCOscillators

This page is a web-friendly rendering of my project notes shared in the LEAP GitHub repository.

Project Source on GitHub Return to the LEAP Catalog
About LEAP

LEAP is my personal collection of electronics projects - usually involving an Arduino or other microprocessor in one way or another. Some are full-blown projects, while many are trivial breadboard experiments, intended to learn and explore something interesting.

Projects are often inspired by things found wild on the net, or ideas from the many great electronics podcasts and YouTube channels. Feel free to borrow liberally, and if you spot any issues do let me know or send a pull-request.

NOTE: For a while I included various scale modelling projects here too, but I've now split them off into a new repository: check out LittleModelArt if you are looking for these projects.

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