Low Voltage Transformer Purchase - What You Need To Know

Looking for a low voltage transformer, but don't know which one to buy? Don't worry - here is the basic knowledge you need to make the right purchase.

Low voltage transformers are often used whenever you want to convert mains voltage to a smaller voltage, like 24v, 12v, 6v or countless other voltages. It could be anything really, but let us first get one thing straight: A transformer is NOT necessarily the same as a power supply - although it CAN be. The transformer - a 12v transformer for instance - is just an electronic component which can be used on its own in some cases, and is part of a power supply in other cases. This information is important, because sometimes you need an actual power supply capable of delivering a DC voltage, while at other times you really need just the transformer.

The first thing you do, is find out exactly what you need. Most of us have a bunch of consumer electronics at home requiring some sort of external power supply. It is often easier and cheaper for manufacturers to build things like stereos, battery chargers and other things this way, which is why these kinds of devices often come with a little black power supply to be plugged in to mains voltage. This is sometimes called a plugpack. These little boxes sometimes contain a transformer, though  not always. If you are missing one of these, go look in the manual of the power-deprived apparatus. This is the first place to look, as it will always be stated here what the power requirements for the device is. It might say something like: "Rated at 12vdc - 500mA - fused" or something like that. This techno babble means that the device needs 12 volts direct current (VDC) and that it is rated to draw a maximum of 500 miliamperes (mA) - and that there is a fuse installed, which most likely will break the connection to mains voltage if the rated maximum is somehow exceeded.

This tells you a lot. Firstly, it tells you that what you need is a POWER SUPPLY - not just a TRANSFORMER. That is because a transformer on its own can not deliver DC voltages - for that, it needs to be followed by extra electronic circuitry, converting AC voltage (what the mains voltage is) to DC voltage. You need to make sure then, that you get your hands on a plugpack that outputs DC voltage at 12v, and is capable of 500mA of power output.

What if you are looking for a low voltage lighting transformer? The same rules apply. Some lighting systems are perfectly with AC voltages, this would often  be the case with something like halogen bulbs for sure. LED's can be a different matter though, so always make sure you understand the specifications and needs before purchasing anything.