The process of voltage inversion with the converter is known as an inverter, which acts as a transformer to convert DC to AC.
The inverter converter is responsible for transforming the alternating current (AC) voltage from the power grid into a stable 12V direct current (DC) output. On the other hand, the inverter converts the 12V DC voltage produced by the adapter into high-frequency and high-voltage AC. Both components utilize the widely used Pulse Width Modulation (PWM) technology. At the heart of these systems is a PWM integrated controller. The adapter incorporates the UC3842 chip, while the inverter employs the TL5001 chip.
The TL5001 chip operates within a working voltage range of 3.6-40V. It is equipped with various essential features including an error amplifier, a regulator, an oscillator, a PWM generator with dead zone control, as well as low-voltage and short-circuit protection circuits. This versatile chip allows for efficient and reliable conversion of the 12V DC voltage output into the required high-frequency high-voltage AC output.
To summarize, the inverter converter and the inverter themselves serve distinct purposes in power conversion. They rely on Pulse Width Modulation technology and employ the UC3842 and TL5001 chips respectively. The TL5001 chip is equipped with various crucial functions such as error amplification, regulation, and protection mechanisms, ensuring the smooth and safe operation of the inverter.
The input interface section consists of three signals: VIN (12V DC input), ENB (working enable voltage), and DIM (panel current control signal). VIN is provided by the adapter, while ENB is generated by the motherboard's MCU with a voltage value of either 0V or 3V. When ENB is set to 0V, the inverter remains inactive, whereas with ENB at 3V, the inverter operates normally. On the other hand, DIM voltage, provided by the motherboard, can range from 0V to 5V. Different DIM values are used to provide feedback to the PWM controller, resulting in varying current outputs from the inverter to the load. It is worth noting that the inverter's current output is greater with smaller DIM values. To sum up, the input interface section includes VIN, ENB, and DIM signals, each playing a significant role in determining the operation and current output of the inverter.
A high-voltage start circuit is employed to activate the backlight tube of the Panel. In this circuit, the ENB is supplied with a high voltage, and the inverter generates a corresponding high voltage output that illuminates the backlight tube.
The PWM controller comes equipped with several essential features, such as an internal reference voltage, an error amplifier, a highly efficient oscillator and PWM functionality. Additionally, it comes equipped with overvoltage protection, undervoltage protection, and short circuit protection. These features allow the controller to ensure reliable and safe operation of the PWM output transistor.
DC conversion involves a voltage conversion circuit that utilizes MOS switch tubes and energy storage inductors. The circuit works by amplifying the input pulse using a push-pull amplifier which then drives the MOS tube to perform switching action. This switching action is what causes the DC voltage to charge and discharge the inductor, ultimately resulting in the other end of the inductor receiving AC voltage.
To achieve the necessary voltage of 1600V for lamp start and subsequently reduce it to 800V, we can employ an LC oscillation and output circuit. This circuit is designed to provide the desired voltage levels efficiently. The LC oscillator generates a high-frequency alternating current (AC) signal, which is then fed into the output circuit.
During the lamp startup phase, the LC oscillator produces a voltage of 1600V. This high voltage is necessary to initiate the lamp's ignition process. The output circuit ensures that this voltage is delivered effectively to the lamp. Once the lamp starts running, the circuit then adjusts the voltage to a lower value of 800V.
By employing this LC oscillation and output circuit, we can ensure a smooth and controlled transition from the high startup voltage to the stable operating voltage. This not only facilitates the efficient illumination of the lamp but also protects it from excessive voltage stress, thereby prolonging its lifespan.
The stabilization of the voltage output of the I inverter is achieved through the utilization of the feedback sampling voltage, which plays a crucial role while the load is functioning.