The vast majority of the lamps The devices we use today rely on it, which is why it's so important to know what it is—a electronic ballast.
Ballasts are an important part of the operation of the light fixtures, especially fluorescent lights, to control and “filter” the flow of electric current in a certain way. It's one of those electrical components which is always present, yet isn't given the importance it deserves. That's why, on this occasion, we'll delve deeper than just the What a ballast is and how it works.
What is the function of ballasts?
Starting with the basics, the function of a ballast is regulate the voltage supplied to a lamp, responsible for supplying the voltage and current necessary for proper operation. They are essential for the operation of fluorescent tubes, PL lamps, and other gas-discharge lamps, as well as some LED lamps, and for this reason, they have undergone significant improvements in recent years. Ballasts are divided into two types:
Magnetic ballasts
They are made with various composite cores made of silicon steel sheet surrounded by copper or aluminum coils, which allows them to convert electrical power into a form suitable for operating fluorescent lamps. Additionally, they feature a capacitor that corrects the power factor to use energy efficiently, and they are the most economical option on the market.
Electronic ballasts
Use solid-state electronic components, such as semiconductors, to turn on and regulate lamps at high frequencies—generally above 20 kHz—although they are usually adjustable. Most of them also have fans to cool the electronic components, and some may even have a microprocessor for greater control and higher levels of precision.
Magnetic Ballast vs. Electronic Ballast
It should be noted that even though at first glance the electronic ballasts are more advanced than the magnetic, both continue to be used side by side due to different needs. And one of the main reasons is that the cost-effectiveness and ease of production of a magnetic ballast It remains the most affordable option for simple, mid-to-low-end devices.
On the other hand, the magnetic ballasts They have the drawback that, due to their composition, they generate vibrations and noise when operating, as well as a flickering effect when turned on; something that does not happen with electronic ballasts. Not to mention that the electronic ballasts They are smaller, lighter, operate at a higher frequency, and significantly extend the lamp's life.
Components of an Electronic Ballast
There are currently many options for electronic ballasts, with a wide variety of components. However, in general, the basic components of an electronic ballast are:
- The EMI filter, responsible for blocking electromagnetic interference.
- The rectifier, which converts alternating current to direct current.
- PFC, a power factor corrector.
- One resonant half-bridge output, which converts direct current into a high-frequency square-wave voltage.
- Control circuit, which, as its name suggests, controls the voltage and current flowing through the lamp, respectively.
Components of an electronic ballast. Balastro.net
Efficiency Parameters
These are the parameters used to determine or analyze the efficiency of ballasts:
- Power Factor: It is defined as the ratio of active power to reactive power (W and VA, respectively) consumed by an electrical load. Values between 0 and 1 are used to define it, with 1 indicating an efficient device—meaning that the device makes the most of the energy it receives.
- Peak value: It is, however, defined as the ratio of a device’s (lamp’s) peak current demand to its average current. It is not a linear value, and the highest peak value determined will indicate the peak current the device can withstand without being damaged.
- Total Harmonic Distortion (THD): This is a parameter that indicates the amount of distortion caused by harmonics in the signal, based on the ratio between two quantities: the root mean square (RMS) value of the harmonic distortion or harmonic components relative to the fundamental or clean component.
