Quote:
TRIAC based dimmers are very efficient. TRIAC based dimmers are relatively inexpensive. TRIAC based dimmers flood your mains with TRIAC induced phase cutting noise!The problem:
I have Lutron TRIAC based phase-cut dimmers all over my house, as do many people these days. These dimmers control dozens of halogen recessed lights and are often set to the 50% position. This floods my mains with 120 Hz transient noise from the TRIACs regulating power via phase-cutting. Here is what the noise looks like (courtesy of davehouston.org):
and an image of the TRIAC operation including the noise spikes (courtesy of hardforum.com):
This has not been a big issue for me to date, because most devices in the home are built to be immune to power line noise.
Recently, I have installed some active monitors (i.e., loudspeakers with the power regulation, amplifier circuitry and crossover circuitry built-in). These monitors do not do a good job of power noise filtering and are picking up the 120 Hz noise being generated by all of the dimmers around the house, causing their woofers to emit a light but annoying buzz at that frequency. Sadly, other than their power main noise intolerance, I love these monitors because they sound great and were reasonably priced.
If I turn all of the dimmers in the house off, the buzzing from the monitors stops. The more dimmers I have set to around 50%, the worse the buzzing from the monitors gets.
Other important info:
The active monitors are on their own 15 amp circuit that is
not shared with the dimmers. However, the noise from the dimmers seems to be going beyond their respective circuits and crossing over to the circuit that the monitors are on (because every circuit in the house is on the same 200 amp main, ultimately). TRIAC phase cutting is efficient, but apparently it also floods your mains with transient noise introduced by the phase cutting that sensitive devices like my monitors pick up.
The question:
What I need is some sort of circuit I can build or device I can purchase that I can place between the power plugs from the active monitors and the noisy outlet to which they are connected. Power conditioners offer no help here, because although they filter out RFI (i.e., high frequency noise), they are useless for filtering out low frequency noise, such as the noise spikes that are being introduced into my power by the dimmers 120 times a second.
They sell coils that can be placed in series between the dimmer and the hot connector that are supposed to reduce (i.e., smooth out the spikes) of each dimmer, but I would have to install one of these for every dimmer, of which I have many, and I would need in-wall space for these things. These coils also buzz themselves, creating a whole new problem. The possibility of replacing all of the dimmers with non-TRIAC based solutions would be expensive and quite a PITA.
I am hoping that there is a circuit I can build or device I can buy that I can place between the monitor power plugs and the wall mains that can filter out or at least decrease dimmer introduced noise (Smoothing it out some so that it becomes a non-issue is also an option). The monitors need up to 1000 W of power at 120 V, by the way, so the circuit would need to be able to accommodate this kind of load.
I seek your expert help in this matter, because although I understand the problem, I have no idea how to solve it. I have a basic knowledge of electronics fundamentals so feel free to get technical in your answer. However, when it comes to high voltage, I'd rather consult with you experts before building something ineffective or worse yet outright dangerous, since we are potentially dealing with some nine amps at 120 V.