- 9V Siren
A surprisingly loud siren for such a simple circuit. Uses voltage controlled oscillator. 1/2 Watt, 8 ohm speaker supplied. 9V operation. Ideal to attach to an alarm system which needs an sound module.
- Music Box Engine
The electronic equivalent of a mechanical music box. Tunes are contained in an M3481 IC - click here for datasheet. It is activated by light falling on an LDR. It then plays a range of tunes. The kit can be placed anywhere you want to hear a tune when light shines on it; opening a cupboard or drawer, music box. Two music ICs and all components, including speaker, provided.
K126 - Mini-VOX and relay
VOX stands for "voice operated switch". Basically this kit picks up audio via a microphone input, amplifies it and uses it to operate a relay. Sensitivity can be adjusted by an onboard trimpot. Use it to give you hands-free control of things like tape recorders, lights, sirens, etc. Relay contacts rated ar 12/24VDC @ 1A. Based on a circuit published in Silicon Chip, Sep 1994, p31