Instructions

Game and Knowledge in Electronics-Lab

Up to now there was only »On« or »Off«.

You can now change the brightness. This is

done with the variable resistor. When you

turn it all the way to the right, the circuit is

closed, just like with

a switch. Turning it

further to the left, a

larger impedance

is introduced. That

means that the current

becomes weaker and

the LED light is less

bright. The variable

resistor is located

between the

connectors VR1 and

VR2. VR stands for

Variable Resistor.

Instead of using the red

LED strip, you can also

install the tricolour LED

and chose your own

colour.

Lighter and darker

A variable resistor is also called a potentiometer.

It is often used for adjusting the volume in radios.

Inside, you would ﬁnd a round strip consisting

of a graphite layer and a sliding contact, which

is adjusted when turning the knob. In this way, you change the

length of the resistor strip and, thus, the impedance. The larger the

impedance, the lower is the current. The photograph shows the

internal construction of a potentiometer with its graphite layer strip

and the rotating sliding contact.