COURSES TAUGHT BY PROF. VALDENILTON: Basic Electronics Course Level 1 and 2 Online (100% in VIDEO) https://go.hotmart.com/S90922297H?dp=1 Digital LCD/LED TV Repair Course (100% in PDF) https://technologycursos.wixsite.com/... Transformer Winding Course (100% in PDF) https://hotm.art/Curso-de-enrolamento... COURSES TAUGHT BY OTHER TEACHERS: Basic Electronics Course (with a focus on repair) https://hotm.art/Curso-de-eletronica-... Basic Electronics Course (with a general focus) https://hotm.art/Curso-de-eletronica-... Cell Phone Repair Course (version 5.0) https://hotm.art/Conserto-de-celular-top Cell Phone Repair Course Notebook Motherboard https://hotm.art/Conserto-de-placa-ma... Voltage Inverter Manufacturing and Repair Course https://hotm.art/Aprenda-a-fazer-inve... Photovoltaic Solar Energy Course https://hotm.art/Curso-energia-solar-... Complete Digital Marketing Course (from scratch) https://hotm.art/Curso-de-Marketing-D... In this video you will learn how the constant current source with bipolar junction transistor (TBJ) works. It is known that the transistor performs three functions in Electronics: a) Signal amplifier; b) Electronic switch; c) Current source. Several electronic equipment use a constant current source in their circuits, to keep the consumption current of these circuits stable. The transistor as a constant current source develops two simultaneous functions: a) Prevents the variation of the input voltage (Vi) from being applied to the load (circuit); b) Prevents the load current (IL) from continuing to rise, limiting this current to a fixed level. A basic constant current source circuit consists of a transistor and a voltage stabilizer circuit. HOW THE TRANSISTOR WORKS AS A CONSTANT CURRENT SOURCE (IN RELATION TO THE VARIATION OF THE INPUT VOLTAGE): When the input voltage rises, the voltage of the Zener diode together with the base-emitter voltage of the transistor remain stable. In this way, the transistor does not leave the Quiescent point (Q) and the output voltage of the emitter remains stable, keeping the voltage at the load unchanged. The excess voltage is then located in the collector/emitter region of the transistor, which, since it does not consume it, ends up transforming it into heat and transferring it to the heat sink. HOW THE TRANSISTOR WORKS AS A CONSTANT CURRENT SOURCE (IN RELATION TO THE VARIATION OF THE LOAD'S CONSUMPTION CURRENT): When the load's consumption current increases, the emitter, collector and input currents also increase. This causes the current flowing through the voltage stabilizer circuit to decrease, thus decreasing the transistor's base current. The decrease in the transistor's base current causes the collector current to decrease. In this way, the transistor's collector current, which was increasing, stabilizes again, keeping the load current stable. I hope that by the end of this video you will be able to analyze the transistor as a constant current source so that you can accurately diagnose electronic equipment boards. VIDEOS TO COMPLEMENT THE STUDY: BIPOLAR TRANSISTOR LOAD LINE • How to measure the DC gain (hFE) of the transi... SHARE THIS VIDEO WITH FRIENDS: • How the DC Current Source Works... SUBSCRIBE TO OUR CHANNEL BY CLICKING THE LINK BELOW: / @technologycursosoficial Hello, I'm Prof. Valdenilton, Technical Coordinator of the Electronics courses taught by Technology Cursos. I love transforming people's lives through teaching. My goal is to teach people like you to fix the electronic equipment they love, helping in every way possible. INFORMATION: Our website: https://technologycursos.wix.com/tech... Business contact: [email protected] Whatsapp Center: (82) 9 8706-9200 COME SAY HI ON MY SOCIAL NETWORKS: Instagram: / technologycursos Facebook: / technologycursos