Variobot varikabi Instructions Manual page 69

D) Operating Principle
1) Resistor
A resistor limits the flow of current in a circuit and
releases energy in the form of heat.
It is used for voltage division, controlling current
strengths, and as protection for sensitive
components.
Resistors often have 4 or 5 colored rings printed
on them, which are referred to as color codes.
In 4-band resistors, the first two rings represent
the value, the third ring is the multiplier, and the
fourth ring is the tolerance.
The 150 Ω (Ohm) resistor in the varikabi kit limits
the current flowing through the two LEDs. The first
brown ring stands for "1", the green for "5", the
second brown one for "times 10" and the gold ring
for an accuracy of ±5%.
The schematic symbol
for a resistor:
2) LEDs
Light Emitting Diodes (LEDs) are components that
convert electrical energy into light by conducting
electrons through a semiconductor layer. They are
known for their energy efficiency, longevity, and
compact size, making them a popular alternative
to incandescent and fluorescent light bulbs.
Unlike incandescent bulbs, however, LEDs need to
be correctly polarized to light up. The shorter leg
and the flat side on the casing mark the negative
terminal (cathode).
Additionally, LEDs require a current-limiting
resistor connected in series with the LED to
regulate the current flowing through it.
R The schematic symbol
for an LED:
A Anode (+)
C Cathode (–)
A K
D