Manual

Project 56 Dim Green Light Tunnel
Build the circuit as shown; the green lights in the light tunnel (U30) should be on but dim.
Push the press switch (S2); the red lights are on dimly but the green lights are off.
Turn on the slide switch (S1); nothing changes (the green lights are still on dimly).
Do you know what is happening here?
This circuit does not have an on/off switch, so disconnect it when you are finished to
avoid draining your batteries.
Use the preceding circuit, but swap the locations of
the 3-snap wire and press switch (S2). The red
LEDs in the light tunnel (U30) should be on but dim.
Push the press switch (S2) to add the green LEDs
to the circuit, or turn on the slide switch (S1) to add
the blue LEDs to the circuit; nothing happens (the
green & blue LEDs stay off).
Project 57
Dim Red Light Tunnel
Use the project 56 circuit, but swap the locations of
the 3-snap wire and slide switch (S1). The blue
LEDs in the light tunnel (U30) should be on but dim.
Push the press switch (S2) to add the red LEDs to
the circuit, or turn on the slide switch (S1) to add
the green LEDs to the circuit. The blue LEDs go off
when you do this.
Use the project 56 circuit, but replace
the 5.1kW resistor (R3) with a 3-snap
wire. The green LEDs in the light tunnel
(U30) should be on brightly. Push the
press switch (S2) to add the red LEDs
to the circuit, or turn on the slide switch
(S1) to add the blue LEDs to the circuit.
Project 59
Bright Light Tunnel
The 5.1kW resistor is no
longer limiting the flow
of electricity, so all the
LEDs are able to shine
brightly.
-49-
The 5.1kW resistor (R3) is limiting the flow of electricity through the light
tunnel LEDs, making them dim. Electricity from the batteries splits up
among the light tunnel LEDs (initially the three green ones), then re-
combines and flows through the resistor and back to the batteries.
Pushing the press switch adds the red LEDs to the circuit. Red LEDs
turn on more easily than green ones, so all the electricity flows through
the red ones instead of the green ones.
Turning on the slide switch adds the blue LEDs to the circuit. Blue LEDs
do not turn on as easily as the green ones, so almost all the electricity
keeps flowing through the green ones (and the blue ones are ignored).
Red LEDs turn on more easily than
green or blue ones, so almost all the
electricity keeps flows through the
red ones if you turn on the press or
slide switches (the green & blue
LEDs are ignored).
Project 58
Dim Blue Light Tunnel
Red or green LEDs turn on more
easily than blue ones, so almost the
electricity flows through the red or
green ones if you turn on the press
or slide switches, and the blue LEDs
are ignored.