home :: power supply :: dc power supply :: build your own 9v 2a dc power supply circuit

Description

The operation of this circuit relies primarily on the capabilities of the voltage regulator. The 7809 integrated circuit is capable of supplying up to 2 amperes consistently, whilst simultaneously maintaining a minimal level of disturbance and ensuring a stable power supply. The design functions effectively without the supplemental elements, however, for safeguarding against reversed voltage input, a 1N5400 diode (D1) is incorporated at the input. Furthermore, the output stage utilizes C2 to enhance noise reduction, and if the circuit is intended to power a digital logic system, a 100nF (C3) ceramic or polyester capacitor is recommended to eliminate any high-frequency switching interference.

Circuit diagram:

Parts:

7809 Positive Voltage Regulator IC

The 7809 is a three-terminal positive voltage regulator IC. It’s a common choice for generating a stable 5V DC supply from a higher voltage source. This integrated circuit operates with a fixed current limit of 2 amps, providing a regulated output despite variations in the input voltage or load current. It utilizes internal feedback circuitry to maintain a constant output voltage, making it suitable for powering sensitive electronic circuits. It typically includes thermal shutdown protection to prevent overheating.

1N5400 Diode

The 1N5400 is a silicon signal diode. It’s a general-purpose diode frequently utilized for rectification, reverse voltage protection, and signal isolation. This diode offers a fast switching speed and a relatively low forward voltage drop, making it suitable for a wide variety of electronic applications. Its specifications include a reverse voltage rating of 100V and a peak reverse current rating of 1A. It's a dependable choice for basic protection circuits.