User Manual

The buttons in the selector (S8) have more electrical
resistance than the button in the press switch (S2),
so pressing S2 makes the LEDs brighter than
pressing the S8 buttons (the difference may be small).
Also, the green LED needs more voltage to operate
than the red LED, and the blue LED needs more
voltage than the green one, so the green & blue LEDs
are more affected by the resistance in the S8 buttons
than the red LED, and may be dimmer. S2 has almost
no resistance, so it makes all the LEDs bright.
Turn on the slide switch (S1) and press buttons on the selector (S8) to
light LEDs in the disco motor (DM). Then push the press switch (S2) to
make all the LEDs brighter.
Place one of the disco covers on
the disco motor (DM) shaft. Turn on
the slide switch (S1), then push
and release the press switch (S2).
The disco motor (DM) spins, but is
not as fast as in project 10.
Project 143
Slower
Disco Ball
Use the preceding circuit but replace
the speaker (SP2) with the red LED
(D1, “+” on right). Turn on the slide
switch (S1), then push and release
the press switch (S2). The disco
motor (DM) should be spinning
slowly. If it does not continue
spinning, then add the red/yellow
LED (D10) across points A & B.
The resistance of the speaker
(SP2) reduces the voltage to the
disco motor (DM), slowing it down.
The disco motor needs more power
to get started than it needs to keep
spinning, so the press switch is
used to get it started.
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Project 144
Selector with Disco
Motor LEDs
Project 142 Slow Disco Ball
The red LED reduces the power
to the disco motor more than
the speaker did, so the disco
motor spins even slower now.
Disco Cover
SUPPORT BAR