Inverter Working Principle

Inverter Working Principle - Power Inverter or usually called an Inverter is a circuit or electronic device that can convert direct electric current (DC) to alternating electric current (AC) at the required voltage and frequency according to the circuit design. Sources of direct electric current or DC current which is the input of the Power Inverter can be in the form of batteries, batteries or solar cells. This inverter will be very useful when used in areas that have limited AC power supply. Because with the Power Inverter, we can use batteries or solar cells to drive household appliances such as televisions, fans, computers or even refrigerators and washing machines which generally require an AC power source with a voltage of 220V or 110V.

The waveforms that can be generated by the Power Inverter include a square wave, a sine wave, a modified sine wave and a pulse width modulated wave depending on the circuit design. the inverter in question. But at this time, the most widely used waveforms are the sine wave and the modified sine wave. While the frequency of the electric current generated is generally around 50Hz or 60Hz with an output voltage of around 120V or 240V. The most commonly encountered electrical power output for consumer products is around 150 watts to 3000 watts.

Inverter Working Principle

Simply put, a Power Inverter that can convert DC electric current to AC electric current only consists of an oscillator circuit, a switch circuit and a CT transformer as shown in the picture below.

The power source in the form of DC electric current with low voltage (eg 12V) is supplied to the Center Tap (CT) of the Secondary Transformer while the other two ends of the Transformer (point A and point B) are connected via a two-way switch to ground circuit. If the switch is connected at point A, it will cause an electric current in line 1 to flow from the positive terminal of the battery to the Center Tap Primary Transformer which then flows to point A of the transformer to ground through the switch. When the switch is moved from point A to point B, the electric current flowing in line 1 will stop and line 2 electric current will start flowing from the positive battery terminal to the Transformer Primary Tap Center to ground through the switch point B. Points A, B and Lines 1, 2 can be seen in the picture above,

The switch ON and OFF or A and B on this switch is controlled by an oscillator circuit that functions as a 50Hz frequency generator, which is to divert electric current from point A to point B and point B to point A at a speed of 50 times per second. Thus, the DC electric current flowing in line 1 and line 2 also alternates 50 times per second so that it is equivalent to AC electric current with a frequency of 50Hz. While the main components used as switches in the Switch Inverter circuit are generally MOSFETs or transistors.

The secondary transformer will produce an output in the form of a higher voltage (eg 120V or 240V) depending on the number of turns in the secondary coil of the transformer or the turns ratio between the primary and secondary transformers used in the inverter.