User Manual

17
Required parts: 9V battery*, 1K resistor (brown black red gold), 100K resistor (brown black
yellow gold), red LED, BC547 transistor, buzzer, 0,5m supplied wire.
How it works: An alarm sounds when the
normally closed security circuit (here
indicated as ‘WIRE’) is interrupted.
Replace this normally closed circuit (WIRE)
by a normally closed window or door
switch; when e.g. the window is opened the
contact within the window switch is inter-
rupted, the security circuit is opened and
the buzzer sounds.
The alarm signal ends as soon as the
security circuit is closed again.