A digital ballast also named as an electrical ballast is a device that reduces the amount of current in an electric circuit. It can be compared to an inductive ballast used in fluorescent lamps, to regulate the current running through the tube which could otherwise be destructive to the negative differential resistance artefact in the lamp’s tube.
Electrical ballasts vary in design convolution. Some can be simple comprising a series of inductors or resistors, capacitors or a combination of the same, while others can be sophisticated as to be used with high-intensity discharge and fluorescent lamps.
Mode of function
A ballast regulates the amount of current passing through an electric load. Typically used when a circuitry in an electrical device has its terminal voltage reducing every time a current passing through it increases. If electrical devices are to be connected to a constant-voltage power supply without the ballast, an increasing amount of current would be drawn damaging the device or interfere with the power supply. The ballast therefore, offer significant positive reactance or resistance that limits that current.
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Composition of an electrical ballast
A typical digital ballast has a resistor and or an inductor. A resistor is placed in-line with the load and can either be a variable or a fixed resistor. A resistor determines the current in the circuit, even when negative resistance is introduced in a circuitry like in the case of a neon lamp.
An inductor, on the other hand, is used with devices that require more than 2 watts electrical power. The component offers proper starting and operational electrical conditions to power a fluorescent lamp or other discharge lamps.
Digital ballasts are used to limit current in lower and higher-powered discharge, fluorescent and neon lamps. They are used in the automotive industry to adjust the ventilation fan speed. In some consumers’ electrical devices like for instance the TV, ballasts are used to drop the excess voltage.