Buzzer, Relay, & Transformer; Buzzer & Relay - Elenco Electronics Snap Circuits Instruction Manual

Project #361
Project #362
Buzzer, Relay, &
Transformer
OBJECTIVE: To use a transformer for a louder buzzer.
Turn on the switch (S1). The speaker (SP) generates a buzzer sound.
As in project 353, the relay (S3) is rapidly switched on and off. This
causes an AC voltage on the secondary of the transformer (T1). The
voltage is stepped-down and applied to the speaker, generating the
sound.
To make the sound a little louder, replace the 0.1µF capacitor (C2)
with a 3-snap wire.
Buzzer & Relay
OBJECTIVE: Make a relay buzzer with speaker.
A speaker (SP) and capacitor (C2) are placed across the coil of the
relay (S3). When the switch (S1) is turned on, the relay's contacts
open and close as in project 353. As the capacitor (C2) charges and
discharges, the speaker generates a buzzing sound.
-26-