12v Regulated Power Supply Circuit Diagram

Here this circuit diagram is for +12V regulated (fixed voltage) DC power supply. This power supply circuit diagram is ideal for an average current requirement of  1Amp. This  circuit is based on IC LM7812. It is a 3-terminal (+ve) voltage regulator IC. It has short circuit  protection , thermal overload protection.  LM7812 IC is from LM78XX series. The LM78XX series IC is  positive voltage regulator IC for different voltage requirements, for example LM7805 IC is made for 5 volt fixed output voltage . There is LM79XX IC series for negative voltage .

Circuit diagram of 12v regulated power supply

Fig: 12V power supply circuit diagram

7805 Voltage Regulator Circuit

A voltage regulator is used to produce a constant linear output voltage. It’s generally used with AC to DC power supply. And also it can be used as well as a DC to DC voltage converter . To regulating low voltage, most used device is one single IC. 7805, 7812, 7905 etc. 78xx series are design for positive and 79xx series are for Negative voltage regulator.

7805 is a three terminal +5v voltage regulator IC from 78XX chips family. See 7805 pinout below. LM78XX series are from National Semiconductor. They are linear positive voltage regulator IC; used to produce a fixed linear stable output voltage.  National Semiconductor has also negative voltage regulator chips family, they indicate with LM 79XX. 78xx is used more than 79xx because negative voltage has a few usability purposes as we see.
I was previously posted a 5v regulated power supply circuit using 7805 IC, that circuit and this 7805 voltage regulator circuit is almost the same.

Circuit diagram of 7805 Voltage Regulator

Fig: 7805 Voltage Regulator Circuit

5V Regulated Power Supply Circuit Diagram

This is a small +5V regulated  power supply circuit. In that case here we used 7805 Voltage Regulator IC. 7805 is a +5 Volt regulator IC from 78xx chips family. The circuit has internal current limiting and thermal protection capacity. A 9V 2A steps down transformer is used to covert 230V to 9V from mains. Here used a bridge rectifier made by four  1N 4007 diode to convert AC-DC . 470uF 50v as C1 is used for filtering. This circuit is very easy to build. For good performance recommended input voltage 8V-18V. If  over 400mA current is needed at output then use a heat sink with the 7805 IC. 

Circuit diagram of 5V Regulated Power Supply

Fig-1: 5V regulated power supply schematic