It is a simple LDR based ‘Happy Birthday To You’ music player. When you block the light falling on the LDR, the kit stops playing the music.
There are 18 flashing LEDs and the buzzer plays “Happy Birthday to You” song. A photoresistor or LDR works here as the photosensitive element. The jumpers are used for bright trigger or dark trigger setting- two modes of operation and another set of the jumper is used to set the buzzer in mute state.
Two trigger mode applications example:
Bright trigger modes: The circuit gets trigged in the bright light.
Dark trigger mode: The circuit gets triggered in darkness.
A transistor has been used as an amplifier for amplifying the music.
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