Elenco Electronic Playground 50-in-1 Experiments - Manual (Page 14)

Since we have two resistors in parallel and a second LED
that is not being used, let’s modify the circuit to match the
schematic below. It’s basically the same circuit but
instead of just parallel resistors there are parallel resistor-
LED circuits. Disconnect the wire between 51 (the
100K
Ω resistor) and 42 (the 3.3KΩ resistor) and connect
it between 51 and 1 (LED1) instead (you may need a
longer wire). Add a wire from 2 (LED1) to 4 (LED2).
Replace the 100K
Ω resistor with several values as before
(such as 1K
Ω, 10KΩ, and others if you wish), pressing
the switch and observing the LEDs each time. The
brightness of LED2 will not change, but the brightness of
LED1 will depend on the resistor value you placed in
series with it.
EXPERIMENT #4B: Comparison of Parallel Currents
-14-
There is an even easier way to explain this:
Wiring Checklist:
o 27-to-56
o 55-to-52-to-43 (2 wires)
o 51-to-1
o 42-to-3
o 2-to-4-to-26 (2 wires)
Water Diagram
On/Off
Valve
Water
Meter
Rocks
Pump
Schematic
Rocks
Water
Meter