Why do we seem to prefer magnetic ballasts over electronic ballasts for HID and fluorescent lighting?

Maybe because magnetic ballasts last longer than electronic ones, cheap small smd transitions and components dies very easily, unlike solid layers of steel and copper winding.

I personally enjoy magnetic ballasts for the sound of their humming and I also like the flash patterns that these ballasts produce on camera.

I prefer magnetic ballasts for fluorescent lamps and high wattage HID lamps because of the long life and simplicity of the ballast, but for lower wattage QMH and CMH lamps (<70W), I prefer electronic ballasts, as lower wattage tends to have lower performance and life on magnetic ballasts.

Magnetic ballasts work on some of the most basic principles of electromagnetics, and nothing more complicated than that. From this originate pretty much all the rest of the higher level reasoning

(It is not true to say that they are ultimately low tech - Modern magnetic ballasts employ advanced insulation materials, steels, have plastic parts that were carefully designed, take advanced automatic processes to assemble, and so on. But none of it changes their mode of operation vs. an 1950's ballast that was wound on more crude steel and insulated with paper)

The reasoning this leads to includes :

 - Reliable against sudden failures - They don't fail as result of trivial causes like common line voltage transients, contamination (within some limits), etc. They dont have highly sensitive components that are susceptible to damage as result of many causes, from latent production defects till EMP. (It is possible to have production defects in a magnetic ballast too, but the possibilities of having a latent defect are very limited compared to complex electronic devices)

 - Reliable against abuse - They have proved to work well in non perfect environments - humid air (within some limits), dirt, etc

 - No inherent limits on ballast life - They have no materials or components that place a hard limit on the ballast life. In Electronic ballasts that includes electrolitic capacitors (rated for 15 years shelf life, and only few 10K's hours at realistic working temperatures), film capacitors (self healing when stressed), the circuit board materials and soldering joints

 - True local manufacturing - Not depending on many advanced components and sub assemblies, that are only made overseas and which manufacturing is more out of reach of local industry



Also, there is a general concept of avoiding "smart" electronic devices and preferring simple devices. This concept is justified in virtually all cases. It takes some stretching to call electronic ballasts "smart", as they dont have any actual computing capabilities - Just a few hardwired functions like programmed start and EOL protections. So i would not apply this concept to the average HF ballast. However, it seems that they get the attitude to some extent just for being electronic devices....

Maybe because magnetic ballasts last longer than electronic ones, cheap small smd transitions and components dies very easily, unlike solid layers of steel and copper winding.

It depends about design, proper components selection and proper ambient temperature: this summer, where i work, we revamped one production line, we retired an old working PLC5 where some parts were made in West Germany (other parts are of the same era) and had run 24/7 since installation.

However, i prefer electronic ballast due weight and efficiency.

They have more character. What's not to like about a quiet hum, interesting startup, and visible flicker? With that being said, there are applications I actually prefer electronic instant-on fluorescents.

The real advantage of electronic ballasts is they dont generate flicker. Efficiency difference is fairly insignificant vs. the best magnetic ballasts. Some specialised magnetic ballasts (a small LNN series made by VS) do actually reach the efficiency of electronic, and if used with electronic starter then all the other advantages of electronic too except the flicker and weight. (for average use, not for watching startup effects...)

The real advantage of electronic ballasts is they dont generate flicker. Efficiency difference is fairly insignificant vs. the best magnetic ballasts. Some specialised magnetic ballasts (a small LNN series made by VS) do actually reach the efficiency of electronic, and if used with electronic starter then all the other advantages of electronic too except the flicker and weight. (for average use, not for watching startup effects...)

With most low pressure lamps, the efficacy is just larger on high frequency. To compensate for this with a magnetic balladt, it would have to have an over unity efficiency so something tells me no magnetic will ever be that.

But why magnetic? It is has proven strongholds and well known and well predictable (so easier to handle, once you do care) weaknesses. The electronic, whatever they could perform better (even reliability wise in many use cases), are just less predictable. It is to a big extend related to the large variability of the possible electrical topologies (that does not mean if it is instant or programmed start, but if e.g. the filament is current vs voltage fed, how the frequency is controlled, what protections are there and how they are triggered,...), where you have no idea what you are up to. So how it responds to different faults, so it is harder to troubleshoot them.

HF ballasts are not "no loss"... While they may feed 32..33W into 36W tube, the ballast input is still in the ~36..38W range. The VS LNN ballasts (for 36W T8 in the size of HID ballast) are around 38W input as well