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Showing posts from January, 2025

Linear regulator current boost circuits

Voltage Regulator Current Boost Circuits Voltage regulators, such as the LM317, 78xx series, or other linear regulators , are commonly used for providing a stable output voltage. However, these regulators have a maximum current limit , often in the range of 1A to 1.5A for typical ICs. To increase the current handling capability, external pass transistors are added in a current boost configuration. How Current Boost Circuits Work The circuits shown in the image use NPN power transistors ( 2N6133, 2N6124 ) to handle additional current while the regulator maintains voltage regulation. First Circuit (Single NPN Pass Transistor) The voltage regulator drives the base of Q1 (2N6133) . The transistor acts as a current amplifier . R1 limits the base current to Q1, ensuring proper operation. The regulator supplies only a small portion of the total current , while Q1 handles most of the load current . Second Circuit (Darlington Configuration with Current Limit) Uses an additional PN...