Power converters are electrical devices that are used to convert DC (direct current) from a battery or other power source to standard household AC (alternating current). They are also commonly known as power inverters and DC to AC converters and inverters. DC to AC inverters are available in various styles. These include printed circuit board (PCB) or card mount, laboratory bench or portable configuration, rack mount, DIN rail mount, wall mount, and stand alone or tower mount. Nominal DC input values for DC to AC inverters can be 12 VDC, 24 VDC, 48 VDC, 110 VDC, 125 VDC, and 250 VDC. Power conversion is needed when taking an output from a battery or UPS for commercial and domestic use.
DC/AC inverters are used in a variety of applications, from small power supplies for items such as computers to large industrial applications which transport bulk power. An inverter can have one or two switched-mode power supplies (SMPS). Basic inverters have an oscillator driving a transistor which is used to interrupt the incoming direct current to create a square wave. This is sent through a transformer to create the required output voltage. Many advanced types of inverters are now using more advanced forms of transistors or similar devices such as thyristors.
While selecting the device, it is important to consider: the number of phases for the output (single or three phase), the input and the output voltage, maximum power, frequency range, the apparent power and if the voltage and frequency are adjustable.
You can also specify if the output is a pure sine wave, square wave, stepped wave or a triangular waveform.
There are also several user interface options for DC/AC inverters these include options for local interface, computer interface, and application software. The electronic display on a power converter can be an analog meter, video display terminal or digital numeric readout. Local interfaces could be analog front panels with potentiometers, dials and switches, and digital front panels that have digital menus and keypads. The options for computer interface include serial or parallel interfaces. Application software is used for controlling or monitoring the performance of the inverter. It is important to be clear about the application or where the power converter would be used.
Power converters come with over voltage and short circuit protection and may be cooled by a fan. If required they can be fitted with a remote switch.