Manual

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56. Magnet & Alarm in Series
Build the circuit, press the switch (62), then hold the
press switch (61). Move the magnet (7) towards the reed
switch (83) and you will hear the alarm (78) sound very
faintly while the motor (95) is off. If you release the press
switch (61), or move the magnet (7) away, the alarm (78)
and motor (95) will turn off. The resistance in the alarm
(78) limits the current in this series circuit, which is why
the motor does not spin.
57. ON-OFF Switch
Build the circuit, press the switch (62), and you will see
the LED (69) and the bi-directional LED (71) turn on at
the same time. If you install the bi-directional LED (71)
in the reverse direction, then press the switch (62), the
LED (69) will turn on red while the bi-directional LED (71)
will turn on blue.
The switch (62) is commonly called an on/off switch
since it just turns the circuit on or off from one location.
For that reason, it’s also referred to as single location
switch. Inside an on/off switch, there’s a spring-loaded
gate. When you change the switch to ON, that gate
snaps closed. It closes the circuit and lets the power ow
through the switch. When you change it to OFF, the gate
snaps open. It opens the circuit and interrupts the ow of
current, making power consumption zero.
Red Light
Blue Light