When you need to derive alternating current (AC) power from direct current (DC) sources like solar panels or batteries, then you need to use power inverters. AC power inverters find uses in numerous applications, from switching power supplies in computers to large-scale, high-powered DC applications in municipal power plants that deliver bulk electrical power to customers.

Transformers allow AC voltage to be converted to any other voltage, though at the same frequency. Inverters (including rectifiers for direct current), however, can convert from any voltage, DC or AC, to any new voltage, also DC or AC, at any required frequency. The power out is limited to what the input power is, but operation is very efficient, with negligible amounts of waste heat. If you're looking for DC to AC inverters, consider the following:

1. Get pricing on solar power inverters.

2. Find out how much it will cost for industrial power inverters.

3. Find the most cost-effective car power inverters.

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Compare the wares and prices of solar DC AC power inverter providers

Solar panels provide DC energy, which needs to be converted to AC to assist in providing 110 amp electrical power to a house or other building.

I recommend: MrSolar, from Online Solar, provides competitive prices for a lengthy list of solar DC to AC power inverter units that you can buy online. Their prices range from about $245 for a 300-watt unit to $3,580 for a 6,000-watt unit. SunPower also has a good selection of power inverters for sale at reasonable prices, ranging to 7,000 watts. Call for prices.

Ask about prices from a few competing vendors of industrial power inverter models

If you need to supply AC power to large equipment or to facilities from a DC source, then an industrial DC to AC inverter is required. Prices are not generally available online for industrial power inverters as they are for solar and other types of inverters. You have to call them for pricing information.

I recommend: Longtime Electronic is a manufacturer and exporter of industrial power inverters. Clayton Power, another industrial DC to AC power inverter manufacturer, has units with inputs ranging from 12 to 36 volts of continuous direct current (VDC) and outputs ranging to 230 volts of continuous alternating current (VAC) at 2,300 watts. Outside Supply's 150-watt units cost $219.95 while their 3,000-watt units are $1,531.25.

Price car power inverters to find the most economical unit for the devices you wish to power

DC AC power inverters come in very handy in vehicles, to power laptops and PDAs and so on. And if you don't have an auto adapter for your cell phone, then an auto inverter will allow you to use your phone adapter that's designed to plug into a wall outlet.

I recommend: Wagan makes a whole line of car DC-to-AC inverters for powering everything from PDAs to color TVs and printer/copier combos. Power inverter distributor Sports Imports has a unit that's the size of a travel cup to fit conveniently into a holder, plugs into a lighter socket and provides a 110 VAC outlet. OnlineCarStereo sells a 140-Watt inverter for $24.95 while a 350-watt inverter will cost $39.95.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Some AC inverters might not give you a perfectly clean AC signal and there can, in some cases, be high frequency noise present. Some power inverter manufacturers include sine wave output circuitry. Most devices will operate fine, but some might be sensitive to the noise. If you're worried about damaging an expensive piece of equipment, determine the characteristics of the AC power generated by the inverter before using it to power the equipment.

You need power to run your electronic devices, but you’re away from an outlet or there’s been a power failure. A DC to AC power inverter, or DC to AC converter, converts direct current from a battery or other source into alternating current to power what you need when the main power goes out.

A DC-AC power inverter can be a printed circuit board or card mount unit, laboratory bench or portable configuration, rack mount, DIN rail mount, wall mount, standalone or tower mount unit. The most common input voltages are 12-volt and 24-volt DC, but 48-volt, 110-volt, 125-volt and 250-volt units are also made. Inverter interfaces include panels and switches, parallel and serial computer interfaces, and monitoring software.

Power inverters deliver power in one of four waveform patterns:

1. Pure sine-wave, mimicking a normal alternating current. This is the best waveform, but requires expensive components to produce.

2. Square wave, which approximates a sine wave with sudden half-cycle shifts from negative to positive and back again.

3. Stepped wave, a typically inexpensive inverter which uses a stepped waveform to imitate either the sine wave or square wave by abruptly switching from zero to maximum voltage, then to zero voltage, then maximum negative voltage and back to zero.

4. Triangular, or saw-toothed, wave.

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Power your business with industrial power inverters

Business' increased use of technology means an increased need for power to run that technology. Industrial power inverters offer that power, either for mobile businesses with high power demands or as a backup system against power interruptions.

I recommend: MDS Power offers Major Series and MajorSine industrial power inverters for sale for utility and telecommunications applications. Inverters R Us sells the 7000-watt, 24-volt Industrial Grade Modified Sine Wave Power Inverter able to power job sites, camping areas and even small houses.

Mobilize your power with car power inverters

With laptops and cell phones permitting people to work anywhere, the car has become a mobile office and its cigarette lighter plug an outlet for productivity when connected to a DC-AC power inverter.

I recommend: Power Systems Direct stocks 12-volt power inverters from Xantrex, Whistler, Cobra, Sima and Vector. Power inverter manufacturer Tripp Lite makes both straight inverters and inverters with built-in chargers that can be used for either mobile or stationary applications, and also offers an online guide to selecting the right DC to AC power inverter.

Think green with a solar AC power inverter

A solar DC to AC inverter converts the DC current from a solar panel into AC current, providing environmentally-responsible independence from power grid fluctuations.

I recommend: Mr. Solar.com carries solar power inverters from MA PV, Outback, Xantrex, Heart, Statpower, Exceltech, Fronius and Morningstar. Top Sales Depot sells 3000- and 3600-watt Power Express photovoltaic power inverters, which you can connect to either solar panels or wind-turbine generators.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Always buy power inverters whose ratings are greater than or equal to the wattage of the devices they will power. If a device is rated by its current draw in amperes, find the wattage by multiplying the amperage by the voltage of the current that powers it normally. For a drill with 2.5 amp current draw running on a 120-volt AC line, 300 watts are necessary to power it (2.5 x 120 = 300).
• •  A 12-volt car battery can handle car power inverters up to 300 watts, enough to power a small TV, laptop or cell phone, although some car cigarette lighters can't handle inverters over 200 watts. More powerful inverters require a deep-cycle battery, the kind used to run golf carts and trolling motors; if necessary, several deep-cycle batteries can be wired in parallel for added capacity.

Power inverters are a big player in today's electronics world. From small to larger applications, these handy converters of power from DC to AC have different roles to play in a variety of common tasks (and tasks that promise to become more common in the future).

The web is a great resource for learning about all kinds of DC to AC power inverters, or for finding formal training options to help a business learn to control this type of "electrical transaction." With help from handy online pages, your search for AC power doesn't need to venture into the realm of the Frankenstinian: using the knowledge of those who have gone before is ideal for all of the uses of power inverters in today's market, including:

1. Help with using power inverters for solar power setups, where the item helps in the process of converting the sun's natural light to clean, renewable energy.

2. Resources for dealing with large "bulk" industrial power inverters.

3. More on using a smaller AC inverter to help run laptops or other devices on the road.

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Find help with using power inverters for solar power

There's a growing movement of people getting their power directly from the sun (and cutting out the middleman). To do this, many use an AC power inverter as part of the electrical process. Find out how from sites that have experience in setting up fully functional solar.

I recommend: The Sun's Eye Power Company maintains solar training that helps students figure out what an inverter is and what kind they need as part of a solar setup. Classes like those at Solar Energy, workshops and other formats, also touch on using a DC to AC power inverter in solar setups.

Get resources for power inverters in general use

Other sites can help you find electrical engineering schools or provide their own instructive materials for those operating or dealing with a large DC to AC inverter or other similar items.

I recommend: Find formal training options for an industrial power inverter and more at schools like Florida International University through easy online course catalogs. Get more attention to items like power inverters with video on electrical issues online from Free Video Lectures.

Locate material on small appliance power inverters

People also use 'residential power inverters' quite frequently to run laptops or other devices from 'battery power.' You can find out a lot more from informative web pages and forums where users deal with the realities of this kind of conversion.

I recommend: Get tips and troubleshooting for laptop DC AC power inverter at forum sites like TechRepublic. Or see other resources like this online Guide to Power Inverters, focusing on how to use power inverter types for roving laptops.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  For any sort of power inverters education and training, see that the material or curriculum fits your intended use by asking thoughtful, intelligent questions before the outset of any formal training.

A power inverter is a device that switches DC power to AC. These devices allow you to run AC powered electronics and other devices from battery power. With a power inverter, there is no panic when the electricity goes out because it acts as a battery-powered backup system. When shopping for power converters, there may be some terms you are unfamiliar with. Learn these power inverters key terms to help decipher all the specifications listed for power inverters.

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Microprocessor

A microprocessor is a small computer chip that processes information and programs. Some power inverters are equipped with processors that control the mechanisms inside the inverter.

I recommend: Find more information about microprocessors at TechTarget. SeoPROMO also provides details about microprocessors.

LED

An LED, or light-emitting diode, is a small semiconductor. LED lights are commonly used as indicator lights on inverter, because they use very little electricity.

I recommend: Cheap 56K supplies information about LEDs. Visit WordIQ.com for even more details about LED lights.

EMI/RFI

EMI/RFI stands for electromagnetic and radio frequency interference. EMI/RFI is a disturbance in electrical currents caused by electromagnetic and radio frequencies. Many power inverters have electromagnetic and radio frequency interference protection.

I recommend: Learn more about EMI/RFI at Digi-Key. Understand EMI/RFI better with information from JMK.

PWM programming

PWM programming, or Pulse Width Modulation programming, is a type of programming used to add an amount of power by switching the on and off time of a periodic signal. Pulse Width Modulation programming is the most common programming used with power inverters.

I recommend: Visit WordPress.com to learn more about Pulse Width Modulation programming. Find even more PWM programming information at Netrino.

Waveform

A waveform is the image of the shape of waves or currents as they move through various materials. Waveforms are used to measure amplitude versus time. There are four types of waveforms used with inverters: sine, square, triangle and sawtooth. These types of waveforms represent the shape of the form. For example, the triangle waveform resembles an isosceles triangle, and the square waveform looks like a square.

I recommend: CNET has more information concerning waveforms. Learn more about waveforms from Tim Carmell. IWEBTOOL also provides details about waveforms.

Peak-to-average ratio (PAR)

Peak-to-average ratio (PAR), crest factor or peak-to-average power ratio (PAPR) is a measurement of waveform. The ratio is calculated by dividing the peak amplitude of the waveform by the RMS, or root mean square, of the waveform.

I recommend: CBS Interactive provides more information about peak-to-average ratios. Rane also offers information about crest factors.