If you are ever interested in using power supply units, there are units a lot cheaper than mine that work great. Look at the voltage ripple RMS as this is what usually manifests itself in the audio bandwidth. The voltage from the AC mains is sinusoidal; capacitors suppress the amplitude of the sine leading to less audible hum. The hum is a periodic residual from the AC mains. You'll be in business if you can find one that's 100 to 150 milliVolts noise and ripple. The power supply units for the old desk top computers pack a wallop. I saw a video of barevid's in the UK using a 175A unit to power a big amp and a Digital Designs subwoofer. Some of the manufacturers that are still around are Astron, Pyramid, ATX, etc; just Google DC power supply or car audio power supply. Circuit City, in the states, used several 100A Audio Authority units, but I'm not sure if Audio Authority is around anymore. In the states, Dereck BigDWiz has a programmable 18VDC/250ADC linear. There's two basic types: linear and switch mode. Linear usually has less than (<) 5 mV ripple, but one disadvantage is they create a lot of heat (they aren't efficient), creating a heat source as we call in thermodynamics. Plus, linear supplies have big transformers and are considerably heavier than switch modes. The switch mode doesn't create all that much heat (they're pretty efficient), lightweight (mine's 36 lbs), but usually have problems with noise and ripple if there is not adequate capacitance at each stage of the power supply. Yep, capacitors are actually useful for something, LOL. Car audio amplifiers and PC power supplies are examples of switch modes. Hence, the presence of capacitors.
I wanted an advanced switch mode to begin with; I had a big budget. The TDK 15-220 has 8 mV ripple with 60 mV noise & ripple peak-to-peak. For residential, you're looking at single phase. In the states a lot of the lower ampacity units are 120VAC, but mine is 240VAC to get to the 220A DC, so I have to install a 30A fuse/circuit breaker. Also, I'm going to buy a 240VAC surge protector to protect my unit given SoCal's Jurassic Park style wild ass storms. **Sigh**. In retrospect, I wish I pursued electrical engineering, but I did not make that realization until my junior year. By then, my student loans were starting to accumulate, they're so effing outrageous in my country, and I had just decided to stick to civil.
I had applied for my Engineer-In-Training certificate a few weeks ago. Unbeknowns to me, in some states it takes 3 months for the certificate to be issued. But, in the mean time I have electronic pdf proof that I passed the Fundamentals exam. I have applied to some transportation engineering places with that new piece of evidence, so now it's just waiting out the meandering applications submission process, LOL.
I've been so bored lately, I started writing a book. I titled it An Asperger's Individual's Manifesto. Instead of chapters it has pet peeves some of us with Asperger's have in common. The first peeve is about Superficiality and our hatred of it; it's public enemy numero uno for our pet peeves. The last chapter I entitled, The Entropy (Chaos) of the Universe Only Increases. In a nutshell it's basically a free-for-all peeve, but it also encapsulates our discontent for people who are ignoring the signs of global warming. Alternating Current has been in static limbo ever since the passing of Tesla. I explore the possibility that J. P. Morgan and our federal government had an arrangement to confiscate Tesla's blueprints to ensure the prosperity of Morgan's descendants' by receiving a revenue-percentage from the electric utilities. Alas, the perpetual wires and the elusiveness of the Tesla Coil and Tesla's radical idea to transmit alternating current via air by such coils and towers. Never again in history would such inventiveness dominate in EE and we are making that ozone hole bigger over Antarctica. In centuries, UV could be bad enough in places like South America where sun blocking umbrella's and vitamin D supplements would be necessary. LOL, Preview-Of-Coming Attractions, not to go off on a tangent or anything. I might publish it when I retire from CE, LOL, I don't know if the Fed's would like my conjectures.
Well it always winds up being a dissertation. L8er Nas.
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