What do I need a ballast for?

Many people ask us about the differences between magnetic and digital ballasts. Sometimes they also ask what they are used for at all. We have therefore tried to answer the most frequently asked questions:

1) Do I need a ballast for all discharge lamps? - Yes, there is no HPS, MH or CMH discharge lamp on the market that does not require a ballast, and it does not matter whether it is 70W or 1000W. An exception can be the CFL compact lamp, which however contains a ballast in its base.

2) Why do I need a ballast then? Because the discharge lamp requires a much higher voltage to "ignite" than the 230V supply, which is provided at startup by a starter (magnetic ballasts) or a voltage converter (electronic ballasts).

3) So the ballast then does nothing? No — during normal operation it limits the voltage below 230V, because the running voltage required by the discharge lamp is lower than the standard 230V.

4) What is the difference between Magnetic and Electronic (Digital) Ballasts?

a) Magnetic - The original technology based on a starter and a choke. Low efficiency caused by a very low light frequency (50Hz); individual components degrade over time, which reduces the ballast's efficiency, and due to their principle they respond with a delay to fluctuations in the mains, which reduces the lamp's lifetime. The ballast also cannot be regulated and operates only at a fixed output. Because of the ferite core of the transformer, buzzing may occur.

b) Electronic (Digital) - Modern ballasts operating on the principle of a frequency voltage converter. They work at a frequency of 30 - 50 kHz (about 1000× higher frequency). Thanks to the electronics they respond instantly to grid fluctuations and always deliver the optimal voltage and current. Most digital ballasts allow switching output power and can therefore be used for lamps of different outputs (a popular setup is a 400W growth discharge lamp and a 600W flowering discharge lamp). Efficiency is also significantly higher, since the ballast's own consumption is approximately one third compared to the magnetic variant. It contains no transformer and is therefore completely silent. Components do not change their properties over time, so their efficiency remains the same throughout their life. The mean time to failure, i.e. the average lifetime, of digital ballasts is also significantly longer than that of their magnetic predecessors, so they are practically superior in every respect. However, these advantages come at a higher purchase price, which is recouped several times over the life of the electronic ballast.

5) How do different ballast brands differ? - Whether magnetic or electronic, it always depends on the components used — their quality and price — which allows the manufacturer to significantly influence both the ballast's lifetime and its efficiency.

6) Which ballasts do you recommend? - In general those we have tested ourselves and those popular with our customers. Mainly:

• Among magnetic ballasts we recommend the time-tested LUMii Black ballasts. They have a protective casing and IEC connectors, which gives them a lower surface temperature and they also work on a Plug & Play principle — so no wiring is required.
• For digital ballasts we recommend Lumatek ballasts, which offer maximum quality for their price, a 5-year warranty and great warranty service. As a price-performance option we recommend the LUMii Black digital ballasts (not to be confused with their magnetic variant of the same name), which are very reliable.
• A separate category are the Lumatek 400V ballasts, which at the same consumption deliver up to 15% more light — but we'll talk about those another time.