Instructions

14
Simplified circuit
diagram of a series
connection
The voltage is divided among the consumers in the circuit. In
this case, there are two LEDs and a resistor. Each white LED
needs about 3V. So, two LEDs have a voltage drop of 6V. And
because the battery has 9V, there is a 3V voltage drop across
the resistor. In this case, therefore, the battery voltage is
divided equally between three consumers. The same applies
to the energy consumption. The resistor does generate a little
useless heat, but the LEDs provide the desired light. Because
this time only one third of the voltage is at the resistor, only
one third of the energy is “wasted”. The circuit with two LEDs
in series is therefore better than that with only one LED, since
only two thirds of the voltage are lost.
6 Parallel connection
This time, the LEDs should be connected in parallel. For this
purpose, a second cable is required. At first glance, both LEDs
light up as in the last experiment. But actually, they are a
little less bright now.