Current Law; Two Pull Power - Elenco Electronics SC3DMEG Instruction Manual

Project 145
Project 146

Current Law

In this circuit, the clear motor (M4) is in series with a parallel circuit. The
parallel circuit has three current paths, S1 & D9, S2 & D11 and S9-D12.
The amount of current flow through the paths are not equal, indicated by
how fast the fan spins.
Turn on the slide switch (S1); the blue LED (D9) lights as the fan spins.
Turn the switch off.
Push the press switch (S2); the blink red LED (D11) starts blinking as the
fan spins.
Finally, place the magnet next to the reed switch (S9); the color2 LED
(D12) lights and but the fan spins very slow or not at all. Try giving the fan
a push to get started.
Turn on all the switches and see how fast the fans spins.
Kirchoff's First Law:
The sum of currents flowing into a junction is equal to
the sum of currents flowing out of that junction.
In this circuit the current from the batteries all flows
through the motor, then divides among the LEDs
whose switches are on, then recombines and flows
through the 3-snap wires and back to the batteries.

Two Pull Power

Assembly :
1. Place the parts on the base grid.
2. Mount the illusion card holder on the clear motor (M4).
3. Place the end of the string in the illusion card holder and wind
the string around the motor shaft a few times.
Holding the string, press the switch (S2) and wind the remaining
string around the motor shaft, then release the switch. Now pull
the string quickly; the motor generates a voltage which lights the
blue LED (D9) if you pulled the string fast enough. Press the switch
again to rewind the string and try again.
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