What is an inverter?
An inverter is an electronic device designed to convert direct current (DC) voltage into alternating current (AC). Typically, the source of DC voltage is a battery. In fact, the inverter also functions as an uninterruptible power supply (UPS), providing reliable electricity to the consumer during power outages in the electrical grid. The duration of the inverter's operation in standalone mode is related to the battery capacity and the total power consumed by the connected equipment.
How does an inverter work?
Under normal conditions, the electrical load is connected to the electrical network. In the event that the voltage in the grid goes out, the inverter activates instantly, providing an output voltage of 220 volts at a frequency of 50 Hertz. In some countries, the voltage may be 120 volts and the frequency 60 Hertz.
Types of inverters
Inverters are divided into two main types based on the modulation method:
- Analog inverters: They generate voltage whose waveform is close to sinusoidal, making them ideal for powering sensitive electronic devices.
- Discrete inverters: They use pulse-width modulation, have high efficiency, and can generate substantial power, but their use may lead to harmonic distortions that adversely affect the operation of household electronics.
Inverter repair
Like any complex electronic device, an inverter can fail. When repairing a powerful converter that uses pulse-width modulation technology, caution is advised. If you lack sufficient electrical knowledge, it’s better not to attempt to troubleshoot by yourself, as this may lead to electric shock. However, if you have certain skills, try to follow these tips.
Steps for inverter repair
- Start by checking the battery. It may have lost capacity and not provide the required current and voltage.
- Check the generator. On the oscilloscope, you should see a waveform close to a sine wave.
- If the generator is functioning, check the power stages by disconnecting the output transistors from the generator and transformer. Each transistor should be tested with a multimeter, and faulty ones should be replaced.
- Finally, inspect the transformer. Pay attention to the smell of burning or discoloration of the winding insulation.
By following these recommendations, you can successfully repair the inverter and restore its functionality.