Security Alarm With LDR (Soldering Kit)

This fun little soldering kit allows you to make a light activating security alarm.

Using an LDR (Light dependent resistor) and an NPN transistor, the LED and buzzer will activate if light shinning on the LDR is above the pre-set threshold. The kit comes with a hardcopy construction guide.

You should be able to assemble this kit in 10-30 minutes with basic soldering skills. The kit is powered using two AAA batteries.

Tools required (not included in this kit):

• Soldering tools
• Wire cutter

Note: For limited period, we throw in free batteries and also upgrade the battery holder to one with cover.