DC to AC Inverter Repair

goodrive200a-inverters

As the name suggests DC to AC inverter it’s a device capable to convert DC energy into AC energy. Despite the simplicity of the definition, there are a large variety of units, having different output characteristics (voltage, frequency, number of phases) and different levels of complexity, starting with simple designs up to very complex and dedicated solutions for specific tasks.

 

Regardless of their complexity all of DC to AC inverter designs can be split into three main stages:

o           Oscillator;

o           Amplifier;

o           Transformer output.

 

Oscillator Stage

 

Starting from DC supply (usually this is provided by lead-acid battery) this stage is responsible for generation of oscillating pulses using either a dedicated IC circuit, or, for simpler designs, just a transistorized circuit. The shape of the pulses and their frequency vary widely according to complexity of the unit, starting from very simple square waves up to very complex form depending of the unit characteristics.

 

Booster or Amplifier

 

The pulses generated by the oscillator stage are very weak and cannot be used to drive the high current output transformers. The booster stage of the DC to AC inverter is responsible to amplify them into to high current levels using either power transistors or MOSFET’s. The output of this stage is AC, but the voltage is small, less than the battery voltage level.

 

Output Transformer

 

The transformer is used to increase the low level AC from the above discussed electronic stages. Depending of the ration between primary and secondary windings the output voltages reach the designed value of the DC to AC inverter.

 

Complex designs of inverters contain different feedback loops between the output and the oscillator, to control and maintain the output parameters (voltage and/or frequency) according the unit specifications, regardless of the external factors (unit load, battery voltage, temperature, etc).

 

Repairing of sophisticated inverters is not as easy as appear, mainly due to their complexity and requires expertise knowledge in the field. Many modern inverters use complex form of wave outputs (true sinusoidal, PWM pulses, etc.) and also implement various feedback techniques to modify the outputs of the oscillator making the troubleshooting of the unit very difficult and requiring specific laboratory equipment.

 

 

Repairing Tips of DC to AC Inverter

 

Often skipped or ignored, the first step should always be the inspection of the DC battery and its connections (and let’s not forget the fuse). Due to high values of current through the connections the corrosion may have a big impact on the inverter.

 

Next step is the oscillator. After is disconnected from the booster, using a frequency meter try to determine if it’s working. No frequency or a stable DC voltage could indicate possible problems.

 

Checking of the amplifier stage or the transformers is a more difficult task and usually requires complex testing equipment and experienced technician.

 

Our team of highly qualified technicians can perform professional DC to AC Inverter repair. We have the experience required, and also the test equipment needed to find the problem of any stage of the DC to AC Inverter, regardless of its complexity. After the fault is found we will provide you an estimation of the repair cost, leaving you to decide if the repair will be done. Usually the repair cost is less than 30% of the price of a new unit.

 

After the approval, we will repair the DC to AC Inverter and test it to assure the customer that the unit will comply with all the manufacturer specified characteristics. We guarantee our repair with up to a full year warranty.

 

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