I have started migrating content to my Hugo blog at https://blog.cavelab.dev, already migrated pages will redirect there.

SOS station toy with yellow and blue LEDs

From CaveLab
SOS station toy with yellow and blue LEDs

This SOS station toy used to make terrible sounds. But after a bit of work it doesn't, it only has LEDs now.

Details

A while back my kids got this SOS station toy, it came with a few emergency cars and the boys quite liked it. My girl friend and myself however; hated it, it had a speaker and made a high siren sound and an annoying voice would shout things like "all cars respond". So I modified it; ripped out the speaker and mounted a few LEDs instead, so now it flashes but no sound.

Originally it had a blue light on the roof, a speaker and four buttons; pressing them would make a siren noise and a voice would start talking/yelling. And the blue light would blink for a few seconds. There was also a "walkie-talkie" thing connected to the speaker. Pretty annoying stuff.

I removed the electronics inside, the speaker, "walkie-talkie" and buttons, kept the blue light but replaced the light bulb with a self-flashing LED. I mounted two yellow LEDs in the roof over the "car port" area, also self-flashing. I plugged three of the four holes where the old buttons had been with rubber gaskets and mounted a toggle switch in the the last one. This turns all the LEDs on and off.

I reused the battery holder, it fits 3 x AA batteries in series, which gives a voltage of 4.5 volts. This is a bit too much for the LEDs, so a few resistors were required. And that was pretty much it. It now flashes yellow and blue when turned on, and does not make any noise. Perfect :)

Video

Gallery

Parts used

Qty. Part
1 × LED 5mm clear, flashing Blue, 3.0-3.4V, 20mA, 7000-8000mcd, 20°
2 × LED 5mm clear, flashing Yellow, 1.8-2.2V, 20mA, 4000-5000mcd, 20°
2 × LED holder 5mm, White plastic
1 × Resistor, carbon film, 0.25W, 75 Ω, 5%
2 × Resistor, carbon film, 0.25W, 150 Ω, 5%
1 × Switch, toggle, 1-pole, micro, MTS-102, on-on, 6mm