Welding reviews
1.Inverters
Inverters are fast taking over from other types of welding machines. These machines are able to provide AC and smooth stable DC output at high-efficiency levels, and feature lightweight construction. The machines operate on either 240 V or 415 V AC input current and immediately rectify this to DC using a series of high temperature diodes. This DC current is stored in filter capacitors and then converted to an oscillated AC output in an oscillator stage at a much higher frequency than the input supply. This high-voltage/high-frequency signal is then fed into a high-efficiency transformer primary coil and high-frequency AC current is produced in the secondary coil. The frequency can be anything from 5 kHz upward, depending on the design and type of output required. Due to the high-frequency AC generated by the oscillator, the weight of transformers can be reduced dramatically because there is no magnetic loss or heat loss through the windings, and much greater transformer efficiencies can be achieved. Now that a high-frequency, low voltage, but high current power supply has been created it can be used as high-frequency AC welding power for MMAW or GTAW of aluminium. Alternatively the AC can then be rectified into DC current again and passed through a second filtering system to produce a very smooth current flow. Welding machines with an output frequency of around 5 kHz demonstrate a characteristic whistling sound during welding. Inverter welding machines have very good electronic controls that can regulate the voltage and current. They are also very efficient and highly portable due to their reduced weight.
The inverter cycle 1. Mains current rectified to DC and stored. 2. DC is oscillated to a high frequency. 3. High-frequency/high voltage AC is transformed to low voltage AC. 4. AC rectified to produce DC. 5. DC filtered to a smooth current. Inverters and advantages 1 Weight reduction, hence portability. 2 Multi process application SMAW,GTAW,GMAW 3 DC output for variety of applications 4 Efficiency 80-90 percent 5 Best performance 6 Ease of controls