Manual

Project 29 Break the Beam
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Assembly:
1. Place base grid supports on base grid A.
2. Place parts on grids B & C, and install into base grid supports on grid A.
3. Install remaining parts on grid A.
4. Add the Q4 attachment.
Turn on the slide switch (S1); the white LED (D6) should be on. Now place
your hand between the white LED and the phototransistor (Q4) and an
alarm should sound.
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This circuit monitors the beam of
light between the white LED and
phototransistor. When you block
the beam, it triggers an alarm. You
could use a circuit like this to help
guard your home from robbers.
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