MC78M12ABT

The MC78M12ABT is a voltage regulatorfrom the family of linear voltage regulators. It is an adjustable three-terminal positive voltage regulator which entrusts a positive voltage of up to 12V and a current of up to 1A. It has in-built thermal protection, which is designed to limit power dissipation and protect against any overheating of the device during multiple current sources.

The voltage regulator is purposely designed for processing constant dc signals, as well as fixed and adjustable DC power supplies in order to provide approved regulation. It is also used as an active load to provide variable load for testing power supplies. Furthermore, the linear voltage regulator can be utilized in solar panel applications as a boosting regulator, LED driving, and general purpose circuit application.

The MC78M12ABT linear voltage regulator features maximum input voltage and minimum output voltage, thermal overload protection current limit, reverse polarity protection, and on/off control. Voltage regulation is simply controlled by the adjustable azimuth knob. With the exception of the MC78M12ABT, all other types also have a temperature range of 0-70 degrees Celsius.

The working principle of MC78M12ABT is intended to monitor and maintain the output voltage at a steady rate, in spite of changes or fluctuations in the input voltage. It is capable of regulating a specific amount of current driven from an external power supply. It has two reference inputs which are configured by an internal voltage divider and compared with a controlled reference voltage across an operational amplifier. The difference between the two voltage signals is further amplified by another operational amplifier, in order to provide a control output signal. This output signal is then utilized to control the pass transistor.

The pass transistor is activated by a small current on the Base of the transistor. The control signal is then passed to the control base via the control current loop. The transistor, acting like a variable resistor, regulates the amount of current that is passed to the output stage. This results in a steady output voltage, despite any fluctuations in the input voltage. The output current of the MC78M12ABT linear voltage regulator can also be limited using an external resistor.

In conclusion, the MC78M12ABT is a cost-effective, low-power consumption three-terminal adjustable positive voltage regulator, an important tool when it comes to providing regulated power at both low and high outputs. It provides an ideal solution for applications where high power is required, or where noise and high frequency ripple need to be suppressed.