inverter circuit diagram

The double-ended working core square wave inverter transformer area product formula Bm represents the maximum magnetic flux. The primary side of the transformer features switches S1 and S2 in parallel with IRF32055. This parallel configuration is primarily due to the need to access the load in the inverter, as the transformer primary current is relatively large. This arrangement helps reduce switch power and prevents damage. The PWM control circuit utilizes the SG3524 chip, which is a voltage-type switching power supply integrated controller. It includes features such as output current limiting, adjustable switching frequency, an error amplifier, a PWM comparator, and a turn-off circuit, which generates a square wave PWM with simple peripheral circuits. When pins 11 and 14 are connected in parallel, the output pulse can vary from 0 to a 95% duty cycle, with the pulse frequency equal to half of the oscillator frequency. When a high signal is applied to pin 10 (off stump), it can block the output pulse. With the external circuit properly connected, under-voltage and over-current protection can be achieved. The SG3524 regulates the internal operational amplifier to drive the output duty cycle D at 50%. After passing through a CD4011, the drive waveform is modified to D < 50%, ensuring that both sets of switches have a common dead time. The DC/AC conversion is performed using a single-phase output in the form of a full-bridge inverter, which reduces size and cost while utilizing an LC filter for frequency output. The circuit employs four IRF740 MOSFETs, each rated for a maximum voltage of 400V, a current of 10A, and a power output of 125W. A half-bridge driver, IR2110, provides the driving signal, with the input waveform sourced from the SG3524. The driver output waveforms of the SG3524 maintain D < 50%, allowing the square wave inverter to ensure a common dead time. The IR2110 is a high-power driver IC designed for MOSFETs and IGBTs, optimizing their performance and providing rapid protection, enhancing the reliability of the control system and simplifying circuit design. The internal structure and operating principles of the IR2110 are depicted in the accompanying figures. HIN and LIN serve as inputs for the pulse signals driving the power MOSFETs in the same bridge inverter arm. The SD pin provides a protection signal input; when set high, it blocks all output signals, while a low connection allows the output to follow the changes in HIN and LIN. HO and LO are the output drive signals for the corresponding MOSFET legs. Proper selection of the bootstrap capacitor for the IR2110 is crucial, as inadequate capacitance can lead to device failure or malfunction. The bootstrap capacitor voltage must exceed 8.3V for proper operation, with options to increase this voltage using small capacitors or providing a dedicated isolated power supply between VB and VS of 10 to 20V. A 1 µF bootstrap capacitor is typically used in the circuit. To minimize output harmonics, the DC/AC inverter section generally employs bipolar modulation, with the inverter bridge operating at high-frequency complementary switching. The undervoltage protection circuit monitors the battery voltage; if it drops below a preset threshold of 10.8V, the protection circuit activates, causing the SG3524 to output a high signal at pin 10, thereby halting the drive signals. The voltage divider formed by resistors R1 and R3 feeds the forward op-amp input voltage, while the negative input is clamped at +7.5V. When the battery voltage falls below the predetermined limit, the operational amplifier activates, producing a negative output that triggers an LED, cuts off three tubes, and sets the SG3524’s SD pin high, blocking the output drive signals.

The described circuit represents a sophisticated approach to inverter design, effectively managing power conversion while ensuring reliability and protection against common failure modes. The use of the SG3524 as a control unit integrates several essential functions into a single component, streamlining the control architecture. The parallel configuration of switches enhances the current handling capability, thereby improving overall efficiency. The IR2110 driver IC plays a pivotal role in managing the switching of the MOSFETs, providing robust protection mechanisms that enhance the system's resilience. The incorporation of undervoltage protection further safeguards the battery and maintains system integrity. Overall, the design exemplifies a comprehensive solution for efficient DC to AC conversion with enhanced safety features.Double-ended working core square wave inverter transformer area product formulaBm is the maximum magnetic flux. Transformer primary side of the switch S1 and S2 in parallel with IRF32055 only reason why parallel, mainly because access to the load in the inverter, the transformer primary current is relatively large, parallel to shunt, which can effectively

reduce the switch power, and will not cause damage. PWM control circuit chip SG3524, is a voltage type switching power supply integrated controller, with output current limit, switching frequency is adjustable, error amplifier, PWM comparator and turn-off circuit, which produces a square wave PWM peripheral circuits required very simple. When the pin 11 and pin 14 parallel, the output pulse from 0 to 95% duty cycle, pulse frequency of the oscillator frequency is equal to 1 / 2.

When the pin 10 (off stump) plus high, can achieve the blockade of the output pulse, and the external circuit properly connected, you can achieve under-voltage, over-current protection. Using SG3524 regulating the internal op amp that comes with the drive waveform of the output duty cycle D, the 50%, and then reverse after CD4011, got on the tube of the drive waveform of D <50%, this can ensure that the two groups switch drive, have a common dead time.

Shown in Figure 3, DC / AC conversion using single-phase output, the form of full-bridge inverter, power inverter for the reduced volume, lower cost, using the frequency out put LC filter. Posed by the four IRF740 bridge inverter circuit, IRF740 maximum voltage 400V, current of 10A, power 125W, using half-bridge driver IR2110 provides driving signal, the input waveform provided by the SG3524, the same way adjustable driver output waveforms of the SG3524 of D <50%, driven by square wave inverter to ensure a common dead time.

IR2110 is a high-power IR company dedicated driver IC MOSFET and IGBT, MOSFET and IGBT to achieve the best driver, but also with rapid complete protection, so it can improve the reliability of the control system to reduce the complexity of the circuit level. IR2110 internal structure and working principle diagram shown in Figure 4. HIN and LIN as the figure in the same bridge inverter bridge arm the next two power MOS drive pulse signal input.

SD for the protection of signal input, when the pin high, then, IR2110 output signal all been blocked, the corresponding constant for the low output; and when connected to the pin low, IR2110 output signal to follow the HIN and LIN and changes in the actual circuit, the termination of the user`s protection circuit output. HO and LO are two output drive signal to drive the same leg of the MOSFET. IR2110 bootstrap capacitor selection is not good, likely to cause damage or chip does not work. Between VB and VS bootstrap capacitor capacitance. Bootstrap capacitor voltage reaches 8. 3V or more, to be able to work, or the use of small-capacity capacitor to increase the charging voltage, either directly in the VB and VS 10 ~ 20V provided between the isolated power supply, the circuit uses a bootstrap capacitor 1 F.

In order to reduce the output harmonics, inverter DC / AC part of the generally used bipolar modulation, the inverter bridge of the pipe is high frequency of complementary and off. Undervoltage protection circuit shown in Figure 5, it monitors the battery voltage condition, if the battery voltage is lower than the default 10.

8V, protection circuit to work, so that the controller SG3524 off stump out of 10 feet high, and stop driving signal output. Figure 5, the forward op amp input voltage from voltage divider R1 and R3 are, while the negative input voltage from the regulator clamped at +7.

5 V, when the battery`s voltage drop exceeds a predetermined value, the operational amplifier to work, the output jump is negative, LED lights, while three tubes V cut-off, the SG3524`s SD-ended output high, blocking the output drive signals 🔗 External reference