What are transformers?
Generally, when people talk of electrical current transformers, they refer to alternating current transformers, as these are more common than constant current transformers. An alternating electrical current transformer measures the current flowing through a circuit - the primary circuit - and then, using this information, it produces a current or voltage that is accurately proportional to the value that is has measured.
What are they used for?
Electrical current transformers are used for a wide range of different electrical devices. These range from electric motors to street lighting. As they can be made to fit a very small surface area, they are often used to detect ground faults, to isolate current feedback signals and to sense current overloads.
What's the difference between alternating and constant current transformers?
The difference between an alternating current transformer and a constant current transformer is that the constant current transformer regulates the current that is passed onto the secondary circuit, and ensures that it is constant. The constant current transformer has a movable secondary winding, which is the key to its function. The secondary winding automatically changes position in response to the current that it has measured. The transformer can be adjusted to ensure that the output is at the desired current.
What is a constant current transformer used for?
The constant current transformer allows for greater control and regulation of the output current, which means that it is good for jobs that require this tight regulation. Street lighting, for example, benefits greatly from the use of a constant current regulator, as lights are constantly powered at a regular current and do not strain under particularly high or low levels.
Why are constant current transformers better for LED downlights?
In most homes where halogen lights have been used for a long time, the transformers in the circuits are likely to be alternating current transformers. However, many people are now opting to use the more energy-efficient LED downlights to reduce the environmental impact of their lighting, as well as cutting their electricity bills. LED downlights do not have to be replaced anywhere near as regularly as halogen lights. LED downlights are particularly sensitive to changes in current, which means that there could be an obvious variation in the brightness of the bulbs. It is also crucial that the electrical current does not exceed the Absolute Maximum Current Rating specified on the LED, as this will compromise the reliability of the bulb. LEDs are built to last, and they'll last longer if the current that powers them is regulated