This circuit simulates an alarm to discourage thieves and it is originally designed to be used on bicycles but can be used for cars too. It blinks a LED on and off thus simulating a real alarm circuit ...

Here is an ultra simple automatic light switch circuit for bedrooms. After construction, connect the input terminals of this circuit in parallel to the internal buzzer terminals of a Quartz-Alarm ...

Back in September, when the Version 9.0 firmware update for Nintendo Switch rolled around, we discovered that the hidden LED light found on your Joy-Con and Pro Controllers was finally about to have a ...

The flashing is thanks to LEDs with a built-in, integrated flashing circuit and the nasty noise comes from a piezoelectric buzzer — both are available from electronics stores that sell ordinary LEDs.