The DC voltage regulator circuit found in many electronic devices. A DC regulator can be inside and outside of the device, namely internal and external regulators. Both function as a power supply that provides an input voltage of the device to operate. A DC regulator is useful for stabilizing the DC output voltage due to changes in input voltage and load current. At certain equipment sometimes takes a rigorous specifications regulator to operate properly.
What is Simple DC Voltage Regulator Circuit?
A simple DC power supply usually uses a transformer as an AC voltage source entry. To convert AC voltage into DC just needed a diode rectifier, an electrolytic capacitor and resistors. The output voltage of a simple circuit tends to be unstable. This is due to variations in AC voltage, temperature and load current. To produce a stable output voltage, a DC voltage regulator circuit is required.
Build a simple DC regulator can use a Zener diode. It's very easy to be constructed by adding a diode rectifier and an electrolytic capacitor. Load current capability of Zener diode depends on the type of each. However, the use of Zener diode as a voltage stabilizer has limitation, because the Zener voltage will drift with temperature.
Integrated DC Voltage Regulator Circuit
In line with technological developments, the voltage regulator circuit is packaged in the form of integrated circuits (ICs). Type Three Terminal Regulator IC which is very popular nowadays one of them is the series 78/79xx. The "78/79" show the regulator positive / negative and "xx" is a fixed output voltage.
Three terminal voltage regulators offer a 5-24 volt voltage rating. This IC simplifies circuit in three pin configurations, input, ground and output. IC regulators offer features over-current and thermal protection installed internally. This IC can be used on devices that require load currents around 1-1.5 A. For larger loads current may be modified using the solid state transistor.
Type of regulator IC is easy to use, but there are some drawbacks compared with switching voltage regulator. IC is only available in fixed output voltage and current. To get a larger current capacity and adjusted output voltage you can use a type LM723 / LM117 as an option.
There are plenty of other options if you want to build a good DC voltage regulator circuit. But you must consider the needs of the load current levels and other requirements necessary. Hopefully this explanation gives an idea of how to build variable voltage regulator circuit is in the application.