AC to DC, DC to DC, DC to AC, and AC to AC transformers convert your available power to the kind your equipment needs.

It is always best to avoid conversion, and use native sources of electricity with native equipment to reduce conversion inefficiencies. But when the need arises, conversion has never been easier.

The first step is understanding what you need to convert and the second is picking the appropriate transformer in the correct power capacity (size).

AC vs DC power:

AC and DC are different animals in the fundamental ways the power behaves in circuits, and both can exist at different potentials (voltages). Working with electrical equipment, you must always be mindful of whether you are working with alternating or direct current, at what voltages, and up to what amperages. Different kinds of bad things can happen if you do not pay attention and understand all these variables when working with power.

Alternating current (AC) runs the city power lines, household outlets, and all the dumb equipment with a power cord in your life (e.g., a toaster). It could be 120V in North America, or 220V, and it could be single phase, or three phase for larger machinery like CNC machines or ovens. Most homes and businesses on developed land with utility power hookups will have split phase 110/220 power supplied into the building, which allows you to natively hook up 110V AC appliances and heavier duty 220V machines like central air conditioning, electric cooktops, or electric dryers — at the same time as 110V devices — over two power wires (often red and black), a green ground, and a white neutral.

Businesses and warehouses may have 3 phase supply where a yellow color will be added. In the US, this is most commonly manifested by either a 208V 3 phase supply which provides both a lightly reduced power three phase for three phase equipment and 120V regular outlet power from the same three wires coming into the building.

Some locations may have a different flavor of three phase such as a high leg delta / center tapped three phase four wire delta, which can also supply the 120V along with a higher voltage 220V three phase more commonly needed by European equipment such as large circular saws.

Even larger factories will often use 480V three phase which supplies three hot wires with 480V measured between any two for the most heavy equipment.

Direct current (DC), on the other hand, will be needed by anything with a chip, or that has a battery for power storage, because batteries cannot store power in AC. DC is also the native output of solar panels. Anything from a calculator to a computer runs on DC power (even if they have an AC power plug, the power is converted to DC for the device). There also exist very large motors that run on DC, as DC allows motors to do certain things that AC motors cannot do.

Common AC power sources:

Power transmission lines, along with the transformers that step down the voltages to the 220V and 110V powering homes and businesses are all sources of AC power. Gas and diesel generators that output AC also produce AC that is more limited in the current they can supply compared to being plugged into the grid. Inverters are equipment that create AC output just like a generator but use battery power (DC) to do so.

Common DC power sources:

Solar panels and batteries are the most common source of DC power. On a smaller scale, every battery from that in your cell phone, to the AAA batteries in your remote, all are sources of DC power.

Why convert from AC to DC?

You probably have dozens of devices around the house that already do this. A vast number of gadgets and lower power devices rely on DC power to operate, so even though these devices may have an AC plug that plugs into 110V AC, they have built-in electronics or a separate brick that converts the AC into the DC at the device's optimal voltage.

Another common reason to convert from AC to DC on a larger scale is for charging battery banks. Many boat owners and RV users who do not have enough room on their vehicle for producing all their power can connect to "shore power" which is a 110V or 220V AC power feed, often of a large amperage like 50A or 100A, to allow for quickly recharging the onboard batteries. A charger or an inverter running backwards (a.k.a. inverter-charger) takes the AC power and transforms it into a high current DC that charges a battery or runs other high power DC load.

Why convert from DC to AC?

Running a house or any dwelling with modern appliances means you want regular outlets, and you need AC power. So even though you collect your power from solar panels in DC, and store them in DC in your battery, many times you will still want easily accessible AC power for your equipment. Even though your laptop technically runs on DC, it's much less of a challenge to use the included AC to DC charger brick that it comes with than finding a DC power source that matches the battery voltage.

So in most cases for a modern lifestyle, unless you go out of your way to avoid AC power, and if you source your power from the sun, you will be using an inverter for some of your devices, which inverts the peaceful DC potential into the rippling AC.

AC to AC conversion scenarios:

Coming across AC to AC conversions in household items is a lot less common now than in the past. You may still find some power bricks that are AC to AC - for example 120V to 24V AC for alarm panel, irrigation, pool lights, or similar equipment. It is important to distinguish between a power brick that outputs 24V DC or 24V AC for example, as those will be for completely different equipment and cannot be interchanged.

On a larger scale, AC to AC conversions are extremely common in the municipal grid, and are in fact the reason for the commercial power distribution grid being AC — AC makes changing voltages easy with simple transformers, and high voltages are needed to run power over long distances. Therefore the grid you see starts with high voltage AC power and steps down several times to reach the safer 120V outlet potentials you are exposed to.

In some cases, you may want to operate a European or Asian 220V piece of equipment and not have a 220V outlet in the kitchen. Here too, you can use an inexpensive transformer to step-up the 120 volts into the 220 your equipment is made for.

DC to DC conversion:

By far the most common situation when you convert between different voltages of DC but stay in DC, is when you harvest solar panel energy to charge a battery. Solar panel power fluctuates, and a DC-DC converter called an MPPT charge controller takes the higher voltage solar panel output and converts it into a steady lower DC voltage to feed your battery or other pure DC equipment, such as a DC air conditioner.

Avoiding conversions between AC to DC, DC to AC, DC to DC, and AC to AC, is always best.

If your power source is solely solar power or other renewable locally generated energy (typically with a battery storage system), you may begin to accumulate more and more pure DC equipment. Pure DC 48 volt mini splits for example, can be significantly more efficient directly on 48 volt battery systems than even a high efficiency rated alternating current air conditioner would from a DC battery with the use of an inverter. Increasingly, more pure DC equipment is becoming available. However, it is not always the same voltage. Higher power equipment tends to run on 48 volt systems, while mid range and lower power equipment often operates on 12V or 24V DC. In these cases, you would use a DC to DC converter to either step up or step down your DC voltage to match your power source to the equipment.

As we only carry quality equipment, efficiency values for all these conversions range in the 94-98% range. While inverters can be very efficient, they tend to draw background power to remain operational, even if there is no load. This could be anywhere from 20 to 200 watts of power depending on inverter size. In contrast, a DC to DC converter will draw negligible current if there is no load connected to its output. So if you have the opportunity to obtain DC equipment to use with your battery or solar install, it will surely be more efficient to convert the DC voltage with a DC-DC converter instead of using AC equipment through an inverter.

Select an appropriate conversion category above to explore our available transformers further.