555 noisemaker

When I started off on the electronics journey I bought the solar powered theramin kit (heliophone) from the makershed I thought it'd be a fun thing for the kids and would be a good starting point for learning to solder. The heliophone uses a solar panel to generate power and produces a clicking noise (the frequency of clicks varies with the intensity of ambient light).

The noisemaker I wanted to make sounds pretty similar but runs off a battery and uses a 555 timer to generate pulses which drive the speaker. Like with the heliophone kit, we alter the frequency of the 'clicks' with changes in ambient light intensity. In this case, it uses the standard "astable" set-up for the 555 and switches R1 for an LDR.

This is a pretty simple set-up and it makes a horrendously annoying noise; so it's perfect for the kids :) My inspiration for this came from this hack-a-day post on tiny-optical-theramins.

I'd already bought a few 555s and LDRs (again due to my eBay issues) so it seemed daft not to make something out of them, especially if the kids were likely to enjoy it.



Here's the final kit. I still want to house it in an interesting way, but I'll have to employ my lady's creative talent to produce something attractive. Maybe I'll paint an alien face on the tin with the LDR sticking through as it's mouth and get the kids to 'feed' it light.


Here's a little test run I did with Ffion, she got distracted pretty quickly by stuff going on in the next room...