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How to Repair Your Luminous Inverter
Charpell Umeh 01:06 Inverter
This article is a do it yourself guide on how to repair your faulty inverter. If you have read my previous post on 7 Common Solutions For Inverter Problems and you still can’t fix your inverter, now is the time to call an expert.
I was compelled to write this because our technicians are repeaing you due to your ignorance of basic inverter component, so they charge you high for their service. The aim of this article is to introduce my readers to the internal architecture of inverter with a view to enlightening you on how to cut costs on repairs.


This article will not teach you everything about inverter repairs, but you will learn the basic component found inside inverter and their function. So when next you’re ready to hire a technician, you will know what you paying for.

It is rather futile discussing how to repair inverter until one becomes fully informed regarding how does an inverter work. Before we move into the fault finding details it would be important to discuss how does an inverter work and the different stages an inverter comprise of. The article walks you through both the aspects which can prove very useful to any electronic technician

Stages of an Inverter
As the name suggests DC to AC inverter is an electronic device which is able to convert a DC voltage from a battery into a stepped-up AC potential which may be quite comparable to the voltage that is found in our domestic PHCN

An inverter normally may be divided into three important stages viz.
1. Oscillator
2. Amplifier
3. Transformer output stage.


Oscillator:
This stage is basically responsible for the generation of oscillating pulses either through an IC circuit or a transistorized circuit. These oscillations are basically the productions of alternate battery positive and negative (ground) voltage peaks with a particular specified frequency (number of positive peaks per second.) Such oscillations are generally in the form of square pillars and are termed as square waves, and the inverters operating with such oscillators are called square wave inverters.


The above generated square wave pulses though are too weak and can never be utilized to drive high current output transformers. Therefore these pulses are fed to the next amplifier stage for the required task



Booster or Amplifier (Driver):

Here the received oscillating frequency is suitably amplified to high current levels using either power transistors or Mosfets. Though the boosted response is an AC, but is still at the battery supply voltage level and therefore cannot be used to operate electrical appliances which work at higher voltage AC potentials. The amplified voltage is therefore finally applied to the output transformer secondary winding.




Output Transformer:
We all know how a transformer works; in Ac/DC power supplies it is normally used to step-down the applied input mains AC to the lower specified AC levels through magnetic induction of its two windings. In inverters a transformer is used for similar purpose but with just opposite orientation, i.e. here the low level AC from the above discussed electronic stages is applied to the secondary windings resulting in an induced stepped up voltage across the primary winding of the transformer. This voltage is finally utilized for powering the various household electrical gadgets like lights, fans, mixers, soldering irons etc.







DC to AC Inverter, Repairing Tips
In the above explanation a couple of things become very critical for obtaining correct results from an inverter. Firstly the generation of the oscillations, due to which the process of voltage induction is able to take place across the windings of the transformer. The second important factor is the frequency of the oscillations, which is fixed as per the country’s specifications, for example countries that supply 230 V, generally have a working frequency of 50 Hz, in other countries where 120 V is specified mostly work at 60 Hz frequency.

Sophisticated electronic gadgets like TV sets, DVD players, computers etc. are never recommended to be operated with square wave inverters. The sharp rise and fall of the square waves are just not suitable for such applications.


Troubleshooting your Luminous Inverter
Once you get well versed with the different stages normally incorporated in an inverter unit as explained above, troubleshooting becomes relatively easy.
The following tips will illustrate how to repair DC to AC inverter:


When you wake up one morning to find your Inverter “Dead”, the first thing you check is battery voltage and connection, then check if the fuse has blown.

If that’s OK, open the inverter outer cover and do the following steps:
Locate the oscillator section; disconnect its output from its preceding stage and using a frequency meter confirm its proper working. No frequency or a stable DC indicates a possible fault with the stage. Check its IC and the associated components for the remedy.

In case you find the oscillator stage working fine, go for the next stage i.e. the amplifier stage. Check each device using a digital multimeter, you may have to completely remove them from the board for the particular tests. If you find a particular device to be faulty just replace it with a new one.

Sometimes transformers also become the major cause for a malfunction. Check for an open winding or a loose internal connection in the associated transformer. If you find it to be suspicious, immediately change it with a new one.

Although it won't be that easy to learn everything about how to repair inverter from this article itself, but definitely things will start "cooking" as you delve into the procedure through a lot of practice and some trial and error.