Alarm By Scr; Light Space War Alarm; Light & Alarm Ic - Elenco Electronics Snap Circuits Instruction Manual

Project #377
Project #379
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Alarm by SCR

OBJECTIVE: To build an alarm circuit.
The circuit uses the space war IC (U3) and works the same way as
project 320. Remove the jumper wire and a space war sound plays.
Project #378

Light Space War Alarm

OBJECTIVE: To build an alarm circuit.
Use the circuit in project 377. Replace the resistor (R3) with the photo
resistor (RP) and remove the jumper wire. Cover the photo resistor
with your hand. Now slowly remove your hand. The music plays
when enough light hits the resistor.
Alarm by SCR
OBJECTIVE: To build an alarm circuit.
The circuit uses the alarm IC (U2) and works the same way as project
377. Remove the jumper wire and an alarm IC sounds.
Project #380
Light & Alarm IC
OBJECTIVE: To build an alarm circuit.
Use the circuit in project 377. Replace the 10kΩ resistor (R4) with the
photo resistor (RP) and remove the jumper wire. When enough light
strikes the photo resistor, the Alarm IC (U2) plays. Cover the photo
resistor with your hand. Now slowly remove it, when enough light hits
the resistor, the IC plays.