A29 Scratchy Amplifier; One Shot - Elenco Electronics SNAP CIRCUITS XP SCXP-50 Instruction Manual

Project #A29
Project A30
-27-
Scratchy Amplifier
Set the adjustable resistor (RV) control lever
to the top and turn on the slide switch (S1).
Talk or blow into the microphone (X1). You
should hear your voice on the speaker (SP)
and the green LED (D2) flashes.
Your voice will not be very loud and may be
badly distorted. Adjust the adjustable resistor
lever for the best sound.

One Shot

Build the circuit, turn on the slide switch (S1), and push the press
switch (S2). The red LED (D1) will be on for a while and then go
off. Push the press switch again to turn the red LED on again.
Use the lever on the adjustable resistor (RV) to control how long
the red LED stays on for.
This circuit can be used as a timer. You might use
a circuit like this in a microwave oven. You press
the switch to turn the oven on and have a knob
(like the adjustable resistor) to adjust how long
the oven stays on; it then shuts off automatically.