The post explains the technical specifications, datasheet, and application notes of the IC 78H12A which is a voltage regulator IC capable of providing a fixed regulated 12V output at maximum 5 amp current.

5 Amp Regulator Specifications


We are familiar with the popular 78XX ICs such as the 7812 IC which can produce 12V fixed voltage at its output with input supplies anywhere from 15V to 24V.

However the above device is capable of handling at the most 1 Amp of current which may be not sufficient for many standard applications.

For circuit applications which require currents as high as 5 amps, a higher rated alternative may be selected in the form of the IC 78H12A which is quite similar to its younger brother 7812 but is capable of handling up to 5 amps of current.

The main technical specifications or datasheet of this IC 78H12A may be studied with the following explanation:

The 78H12A is a three terminal  linear, positive fixed voltage regulator IC rated for continuously delivering around 5 amps of current with typical fixed 12 volts at its output.

The IC is internally fully protected a against short circuits or over loads at its output which makes it highly rugged and versatile.

In an event of a short circuit or over load across its output terminals, the device instantly shuts down the supply of power across its output leads, thus inhibiting any possibility of electrical hazards. The situation also protects the IC from getting damaged.

The above feature ensures safe operations of the connected electronics and also avoids the inclusion of external safety circuits reducing the cost and the component count of the over all configuration.

The device is available in a hermetically sealed TO-3 metal package, and facilitates easy fitting of an heatsink for better efficiency and working of the device.

Main Technical Features of the IC


The main features of the IC may be summarized as follows:

  1. Output Voltage: 12V, fixed, regulated

  2. Output Current: Maximum 5 Amps

  3. Protections: In-built short circuit and over load protected.

  4. Power Dissipation: 12 x 5 = 50 to 60 Amp Approximately

  5. Package: TO-3 metal body


Pin Outs of IC 78H12A


The figure below shows the pinout details of the IC 78H12A, if the device is held with the pins toward us and with the larger plain section of the area upwards, the right pin is the input, the left pin is the output while the body becomes the ground of the IC.


Application Notes


The IC 78H12A is fundamentally suited for all electronic circuit application where a fixed 12V is imperative and with requirements upto 5 amp, example for driving 12V DC motors, for driving high watt white LeDs for flood lighting, and also for charging lead acid batteries (with some modifications).

The following diagrams illustrate a couple of main applications which may be implemented with this versatile 12V 5 amp fixed voltage regulator IC.
12V 50 AH Battery Charger Circuit


30 watt LED Driver Circuit

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