These are two - easy to build - relay-based alarms. You can use them to protect your motorcycle - but they have many more applications. If you use relays with 6-volt coils - they`ll protect your `Classic Bike`. Both alarms are very small. The completed boards occupy about half a cubic-inch - 8 cc. The standby current is zero - so they won`t drain your battery.
Circuit Number Five uses a SPCO/SPDT relay - but you really only need to use a SPST relay. If you are going to use the veroboard layout provided - you`ll need to use the style of relay specified. But you can build the alarm using whatever style of re