Ordinary "wall wart" or "pulsed phased" or "switching" voltage transformers are typically very dirty and contribute greatly to contamination to your power supply. This is a recent phenomena. Over the last 15 years they have proliferated with mobile phones and computers in sequence for charging and powering.
The old fashioned ones were safe as they used 2 copper coils. With micro chips came switching and this causes SPARKING that creates a powerful burst of radio frequencies many times a second. LISTEN TO YOURS WITH A RADIO on the AM band at ALL frequencies. Some are better than others but all are bad as that burst goes down the wires as well.
As Stalin said you can leave the West to EMR poison its self out of existence. Most of these are coming from China now. There are nearly no clean alternatives available now. Those that are available are very expensive. IE magnetic voltage transformers. Look for linear power supplies (regulated) or linear mag amps.
If you are EHS you most certainly should be powering all your devices with linear 12vDC power and 5vDC. IE TVs computers etc.
If you are interested in all this read Electromagnetic Man by Cyril Smith. He discuses these 50 and 60Hz issues and explains risks and effects.
If you need a clear DC source for charging your USB devises I have just found one cheap on eBay.
LT1083CP Linear Voltage Adjustable Regulated Power Supply Module Board
My radio did not pick up any dirty radio emissions. This does need a bit of wiring up but it is worth it. Especially for charging batteries, it would be well handy, as I have never found a clean battery charger.
Does any one else have experiences with clean 12vDC?
Has any one come across any info that explains the dangers of live electric fields well? I mean the stuff that an electromagnetic field meter picks up in AC fields. It is the biggest danger for EHS and no one here seems to have picked up on it. They are illegal in consumer goods but my meter goes nuts in most UK shops. Not in France though. They do enforce the EU law banning rubbish electric items.
Even BIGGER question???? I desperately need to know PLEASE?
Please how is it that a 220vAC device that has a live electric field can cause the same reading (1400) in a connected 12vDC or 5vDC USB peripheral device like a mouse or keyboard?
I have been try every where to find this out. Its doing my head in. It is not addressed on the Internet anywhere that I can find. I have written to many people but no one seems to know. I you know I will give you my gold star.
The output was set to 10V. I connected that to a 10W halogen bulb through a 25' extension cord (non-coaxial), and the noise on my Radio Shack 12-467 was no higher than the background in the room when I held it right up to the cord.
To double-check, I kept the volume setting unchanged and held it next to the transformer and the power cord from the wall, both of which produced copious noise.
So anyway, I think it works well. (The real test will be at 12V, though.)
The adjustment requires using a small screwdriver to change the settings on two variable resistors, and you need a multimeter to measure what it is. (There are two through-hole contacts at each resistor to make that a little easier.)
Given the number of people in the world it always surprises me just how hard it is to find the bits to live on DC voltages.
Has any one found links to good sites please?
DC certainly offers HUGE health advantages. It is tricky though. It can be done badly and be dangerous. Finger rings and metal watches being obvious examples near batteries.
I am amased that more EHS don't try it. It is essential for night time lighting and sleeping without AC electrickery.
I love making my own torches. Bulbs are so advanced compared to when I was growing up. I have been a candle maker for 40 years but feel a bit surpassed but tech now. There is still nothing like a big candle. The apps just aint got it for that.
Have you got any ideas about building a linear solar charge controller?
If you mean something based on an LM317 or similar, why not use a rheostat instead? The only difference between the two is that the LM317 actively stabilizes its output voltage, but that shouldn't matter for a battery charger unless you're sitting right next to the battery or you have a long DC extension cord between the regulator and the battery. They're both just variable resistors.
If you want something more efficient, your main options are various types of transformers, all of which make electromagnetic noise.