Light Alarm
A sensitive photo Darlington transistor is used with CMOS NAND gate.
The circuit detects light and triggers a siren. You could add your own
triac or relay and switch practically anything. The kit uses the
MEL12 Darlington super-alpha phototransistors, typically about
ten times more sensitive than a normal phototransistor.
The circuit usage includes burglar alarms, medicine cabinet alarm,
automobile trunk alarm etc..
