Just finished the first of our Tech Weekends. We had a great time (and hope the children did as well!) Most of them opted to build a laser tag game gun but Barney chose other kits and it was interesting to see what he was able to do with connecting some off-the-shelf kits. His first one was a siren with adjustable pitch and sound effect.

His second was a ‘clap switch’ which can turn a device on or off by clapping twice. By connecting these two together with a reed switch (a magnetically-operated switch), he created a burglar alarm that can sense a door opening and sound a siren, but one that can be armed and disarmed by clapping. It was a creative way of combining the projects. And just in case any would-be burglars think they’ve got the heads-up on Barney’s new security system, you have to already be in the room to be close enough to the microphone to be able to disarm the system! (And there’s also no guarantee he hasn’t already modified it to electrify the door knobs as well!)