A DC-AC Modified Sine Wave Inverter with Output Short-circuit Protection Circuit

With the continuous improvement of people's quality of life, portable power tool equipment has become increasingly popular. To expand the use of battery packs for portable power tools, modified sine wave inverters are widely used by outdoor enthusiasts due to their small size and low cost.

However, the output protection of ordinary modified sine wave inverters detects current following voltage. If the actual equipment used is a capacitive or inductive load (such as induction cookers, fans, projectors, etc.), due to the characteristics of current leading or lagging voltage, it is easy to fail to detect voltage and current synchronization, resulting in misdetection of the inverter, causing damage to the H-bridge MOSFET in the inverter circuit and output failure.

Click Power has provided a breakthrough solution to this technical bottleneck with its independent innovation of the invention patent for "DC-AC Modified Sine Wave Inverter with Output Short-circuit Protection Circuit".

【Technical Solution】
Aiming at the deficiencies of existing modified sine wave inverters, a design scheme for output short-circuit and start-up instant protection circuits suitable for capacitive and inuctive loads is proposed.

【Innovative Highlights】
It can not only meet the start-up and short-circuit protection of conventional resistive loads, but also timely send real-time segmented detection of current and voltage to the MCU for functional judgment, thus better satisfying the phenomenon that actual capacitive and inductive devices in life are not easy to be damaged during use.

【Patent Value】
By setting up short-circuit and start-up instant detection protection units in the modified sine wave inverter, the purpose of protecting the modified sine wave inverter is finally achieved, with simple structure, low cost and fast response speed. The product is not easy to be damaged and enhances the user experience.

【Core Application Scenarios and Advantages】

1. Office and Digital Equipment
   Applicable devices: laptops, printers, scanners, fax machines, mobile phone chargers, digital cameras, camcorders, etc.
   √ These devices usually use switching power supplies and have strong adaptability to input waveforms. Modified sine wave inverters can provide stable power supply.

2. Home Entertainment Equipment
   Applicable devices: televisions, DVD/BD players, game consoles, audio systems, lighting fixtures (such as LED lights, energy-saving lamps), etc.
   √ Solves the problem that some high-precision audio devices may be affected by harmonic interference, leading to reduced sound quality.

3. Small Household Appliances
   Applicable devices: electric fans, microwave ovens (some models), electric heating cups, hair dryers (low-power models), etc.
   √ For appliances with motors or compressors (such as refrigerators, air conditioners), solves the problem that existing modified sine wave inverters may not provide the waveforms required for stable operation, easily causing equipment damage or reduced efficiency.

4. Outdoor and Emergency Power Supplies
   Application scenarios: camping, self-driving tours, field operations, emergency backup power supplies, etc.
   √ Low price, suitable for providing temporary power support for mobile phones, lighting, small appliances, etc.

Click Power has always driven development with technological innovation, and continues to provide customers with safer and more reliable power solutions.