Elenco Electronics SNAP CIRCUITS SKILL BUILDER - Project 120 Light to Dark; Light to Dark Circuit; Project 121 Power Shifter; Power Shifter Circuit

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Turn on the slide switch (S1), the brightness of the LED (D1)
depends on how LITTLE light shines on the photoresistor
(RP). The resistance drops as more light shines, diverting
current away from the NPN transistor (Q2).
When you turn on the slide switch (S1), the LED (D1) is on
and the lamp (L1) is off.
Push the press switch (S2) to bypass the LED. The lamp
turns on and the LED turns off. This shows how switches
can be used to shift power between different devices.
Project 120
Project 121
Light to Dark
Power Shifter