hehe it is the new marketing.
Saturate internet with your stuff until there is only one truth left...yours.
Fortunately, not everyone shares your opinion. Of my message regarding the adverse effects of Harmonics in motion picture lighting, Harry Box, Author of "Set Lighting Technician's Handbook" had this to say:
"Great work!... this is the kind of thing I think very few technician's ever get to see, and as a result many people have absolutely no idea why things stop working." - Harry Box, Author of "Set Lighting Technician's Handbook"
I was also invited by the steering committee of the Electrical Department of IATSE Local 481 to present on Harmonics as part of the “Advanced Power and Generation for Set Lighting Technicians Seminar” offered by Russ Saunders of Saunders Electric (the provider of power generation services for the Academy Awards since 1952 and a recipient of a technical Emmy). Of my presentation, Russ Saunders had this to say to the electricians of IATSE Local 481:
Guy Holt is "among the 1% of film technicians world wide that truly understand the dynamics of power generation and Harmonics." - Russ Saunders of Saunders Electric
I have not been “saturat(ing) the internet with (my) stuff until there is only one truth left...(mine).” My message is not ‘my truth’ as nosys70 suggests, it is the truth.
As much as Chris would like you to believe, I’m not posting the same post over and over as a way of marketing equipment I sell. If it seems like I am posting the same thing over and over it is because harmonic noise is generated by all kinds of production equipment. I post these oscilloscope shots where ever I can because the harmonic noise is a growing problem in production and should be eliminated whenever possible.
But, don't take just my word that harmonic currents can cause problems for electronic production equipment: according to the Caterpillar Application and Installation Guide for "Electric Power Applications, Engine and Generator Sizing" *: "Most loads will continue to operate with THD at 15 to 20%. However, loads with sensitive electronic equipment can develop problems with THD greater than 5%." The THD value of the severe voltage waveform distortion, generated by two 1200 Pars (with non-PFC ballasts) operating on a conventional AVR gas generator, that can been seen in the oscilloscope shots in my posts is well over 100%. There is no question that THD values of this magnitude in a power waveform will cause erratic behavior in electronic production equipment running on the same distribution system.
Me presenting to the electrical department of IATSE Local 481
But don't just take my word for it. Here is a bit of anecdotal evidence relayed to me by Dave Talamas, the owner and chief engineer, of Talamas Broadcast Systems, in Newton Ma.: they sent several non-linear editing systems to the Iron Man Triathlon for field editing. The laptops kept inexplicably locking up. They put a scope meter on the power supply which was coming from a generator that was also supplying a large number of HMIs and found the voltage waveform was severely distorted. They moved the lap tops to the onboard generator of a satellite truck. Once they were moved from the highly distorted power supply of the lighting generator to the highly refined power supply of the satellite truck the laptops operated flawlessly.
And, I'm not scare-mongering when I warn that harmonic currents can cause problems for electronic production equipment. But again, don't just take my word for it: apparently, harmonics when using a generator for lighting is enough of a problem to warrant several sections in the third edition of the "Set Lighting Technicianís Handbook." ** To quote Harry Box (Page 337 under "Power Problems from Electronic Loads"):
"Much of today's lighting technology relies on electronics such as DC rectifiers (electronic HMI ballasts), silicone-controlled rectifiers (SCRs), capacitors (magnetic & electronic HMI ballasts), and high-frequency switching power supplies (the IGBTs of electronic ballasts). These kinds of load can have undesirable effects on the current waveform, revealing themselves in the form of overheating or failing equipment , efficiency losses, circuit breaker trips, excessive current on the neutral wire, interference and instability with generators, noisy or overheating transformers and service equipment, and even loosened electrical connections. In the following sections, we discuss the power factor and current harmonics and look at their effects. Your awareness of these effects will help you to build systems that avoid or mitigate problems and show how to test for problems.(the parenthesis are mine)"
Now does this sound like harmonics is not a problem when using a generator for lighting and I am just "scaremongering"? The problem exists. Now you can either deny it and be worse off for it; or as Harry Box suggests, you can accept it and "your awareness of these effects will help you to build systems that avoid or mitigate problems (on set.)" Which, incidentally, is all that I have tried to do in my posts.
Guy Holt, Gaffer, ScreenLight & Grip , Boston
* Caterpillar. "Application and Installation Guide for Electric Power Applications, Engine and Generator Sizing (CAT publication LEBE5294." (Online) Available at the Caterpillar Electronic Media Center.
** Box, Harry. Set Lighting Technician's Handbook, Third Edition. London: Elsevier Press.