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... SHARE THIS VIDEO WITH FRIENDS: • Learn to Analyze (In Theory and in Pr... Introduction: The starting circuit is responsible for initializing the microprocessor, which in turn releases the operation of the main source that will power the various circuits of the digital TV. In this video, you will learn to analyze (in theory and in practice) how the Digital TV starting circuit turns this electronic device on and off. Definition: The digital TV starting circuit can be found in several forms and the most common are transistorized, followed by those with photocouplers and finally those that use integrated circuits. Application area: The starting circuit is found in all remotely controlled equipment, be it in any area: Consumer electronics, power electronics, computers, household appliances, etc. In this video specifically, we will analyze the operating principle of the transistorized digital TV starting circuit. The transistorized circuit can be formed by bipolar transistors, MOSFET transistors or in a hybrid form (bipolar transistor + MOSFET transistor). The transistorized digital TV starting circuit can be composed of 2, 3, 4, 5 and even 6 transistors. Operating Principle: In this video, we will analyze a hybrid digital TV start-up circuit, consisting of only two transistors: one of the NPN TBJ type and the other of the P-channel MOSFET type. In this transistorized start-up circuit, the standby voltage of the power supply, with a value of 3.3 V, is applied to the source and gate terminals simultaneously, forcing this transistor to enter the cut-off state. With the P-channel MOSFET in the cut-off state, the drain voltage is at 0 V, preventing the Microprocessor IC from starting up. This same PMOS gate supply voltage is also present at the TBJ collector, which is connected directly to the PMOS gate. With the TBJ in the cut-off state, its collector voltage VCE is equal to the standby source voltage (3.3 V), which keeps the PMOS in the cut-off state. The Power ON/OFF command will be applied to the base of the TBJ. This command has two levels: low (0 V) and high (3.3 V). The level change of this command occurs whenever the user presses the Power button on the remote control. With the Power On command at a low level, the JTB remains in the cut-off position (off) and its collector voltage is equal to that of the standby source (3.3 V), preventing the MOSFET from conduction, keeping the Microprocessor IC off. When pressing the Power key on the remote control, the Power ON/OFF command rises to a high level (3.3 V) and polarizes the JTB base, generating a base current (Ib). The JTB base current generates the collector current, causing the collector voltage to drop to close to 0 V. With the JTB collector voltage dropping to 0 V, the P-channel MOSFET gate has a voltage level lower than the source terminal, causing the MOSFET to open the P-channel, allowing the standby voltage to appear at its drain terminal. The PMOS drain voltage goes to the Microprocessor IC, which, when polarized by it, releases the operation of the main source, which will generate the voltages necessary to power the digital TV stages. Conclusion: I hope that, at the end of this class, you will be able to analyze theoretically and measure practically a digital TV starting circuit. Hello, I am Professor 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 repair 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