With ABRA's best selling Alarm Kit you learn basic electronic principles while building a simple burglar alarm to protect your house, room, close or windows.
This multifunctional device is easy to use in a variety of applications : 1) LED control of set fluid level : LOW, MIDDLE, HIGH ; 2) Controller : the relay automatically switches a pump and/or valve to keep the fluid level between the LOW and HIGH marks ; 3) Alarm : if the sensor detects a level which is too high or too low (selectable), the relay will operate a bell or other alarm device.
This is the size of a dime, yet transmits both sides of a phone conversation to any FM radio. No battery needed. Requires soldering.
This kit creates an invisible beam of light that will sound an alert whenever it is broken. Uses IR emitting LEDs for the transmitter to send a powerful beam up to 13 feet.
This kit gives an alarm sound when water is detected. Incorporated alarm buzzer. Water sensor can be placed at a distance by cutting the board and using wires to connect the sensor.