SCAM: Electronic Rust/Corrosion Prevention

My friend bought himself a new car. The dealer sold him on sports rims, trim and the like, and something called an electronic rust preventer.
The dealer said that this prevented cost around 1200 dollars, but would be thrown in for "free" if he got this sports pack. So be it, it was put on.
I didn't know much about these things at the time, but i had heard that they were a scam from a variety of sources on the internet, and the fact that
with you know physics, its absolutely impossible for it to actually work as intended. There is a kind of rust prevention called cathodic protection,
that involves a sacrifical anode and a conductive sorrounding, like water. This system is used on boats, with blocks of zinc bolted to the hull. In sea water a kind of battery is created with current flowing between the zinc and the hull, and the zinc slowly being corroded away, leaving the boat hull
untouched.
The "electronic" rust prevention system is apparently designed to "cover" the car with a "electron cloud" that prevents rust. Right...

The sites i have found have never actually described how its supposed to work, but only offer some form of vague explanation.

Here is one site http://www.defensepak.com.au/CECI.htm

".. sends a continuous stream of silent electronic pulses throughout the body of the vehicle. These pulses act to inhibit the electro-chemical process, drastically reducing the rate at which rust forms."

Apparently electronic pulses inhibit a electro chemical process.
The biggest flaw with this particular statement, other then the fact that there absolutely no proof that electronic pulses would inhibit something is the
method in which these "pulses" were applied to the car frame. Oh and the fact that cars are made of zinc coated steel, painted and rust proofed which are all apprently actually useless unless you have one of these devices.

These devices all share some common characteristics. Pulsing LED. Simple two wire connection to the car battery. No actually connection to the frame of the car other then through the earth lead on the battery. Attatchment is usually via double sided tape which is electrically insulative.

I have the device here, and have taken it apart, and taken pictures. For more information check this column, where I learned some more about these things.

Particulars of this device.

Found blinking away on the frame at the front of the car down near the left hand wheel. Attatched via black double sided sticky tape. Wasn't stuck down very well either. Green LED flashing around .5 hz, one second on, one second off. It was open to the enviroment and was covered in road grime and dirt.

After removing it from the frame, which just needed a bit of a pry, i then disconnected it from the battery terminals. There are only two wires to this device, earth and power. (12 volts DC)

What it looks like removed.

A bit of a clean had to be done to get down to the finer details.

Havn't called that number, and the company doesnt have any presence on the internet. For a "amazing rust preventative product" that revolutionises the rust preventing industry, there is really nothing out there that even describes or indicates this company actually exists. Aways a good sign.

The body of the device is extruded aluminum, with plastic ends. Typical of cheap devices mass produced.

That back of the device. It was covered in black double sided tape that i removed. There are no contacts sticking through to touch the frame (which would still be painted and thus not conductive).

Opened up. The PCB was held in with hot glue ( Surely a sign of high technology manufacturer, and worth the 1200 dollars. )
The hole for the LED has just been drilled, no seal. There are no seals or sealant of any kind, and the pcb nearly fell out of the assembly.

This is the lead into the box. No sealing, and this three inch wire heatshrinked to the lead. It doesnt go anywhere.

This device has the feel of a cheap two dollar knock off, but this IS a real device, so.. yea.

The actual circuit board. The chip has markings, but are horribly faded. If you notice near the wires soldered to the board that there is corrosion.
Yes.. corrosion INSIDE the device designed to prevent corrosion. This is really going well.
The led is a special device, it actually has a built in chip that controls the flashing. All these LEDS need is a power supply and a current limiting resistor marked just to the right of the red wire, marked R3. The rest of the circuit is quite easy to follow. The one and only chip (which in some advertisments is the "computerised" controller) is only an 8 pin surface mount oscilator, probably a CMOS 555 chip or similar. The rest of the circuit consists only of capacitors and diodes which create a circuit known to all high voltage enthusiasts known as a Cockcroft-Walton multiplier.
A wikipedia article is here, with a sample circuit shown here.
More details are shown in this pdf.
Given the number of stages, and the supply voltage of 12 volts, this circuit creates approximately 100 volts of extremely low current DC.
DIRECT CURRENT is the key. The output of a cockcroft-walton circuit is direct current, no "pulses" as mentioned in the advertisment.
The output of this multiplier is fed to the short wire which is heatshrinked to the lead coming into the device. It is also fed to the blank PCB on the back of the board.

Thats it. Thats the entire thing. A flashing LED which just sits there draining battery voltage and a low current 100 volt dc supply that actually doesnt go anywhere. It supplies that voltage to an insulated pcb plate, and a small wire leading out of the device. Even if the mechanism of current pulses did actually do anything, the output of this device is actually DC, and no pulses!
And the corrosion INSIDE this unit is also a good indicator of its effectiveness. Horribly manufactured, unproven effectiveness, and downright stupid claims of rust prevention by somehow stopping the chemical reaction of rust at a DISTANCE using some amazing electronic effect of 100 volts DC somehow coating the outside of car.... I dont know what else to say.

This is what some people will pay over a thousand dollars for. What a scam.

For any questions, email rainwulf@gmail.com

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