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Re: [EVDL] Magnetic Shock Absorber & EV

Peltier devices use effect nr 2, in that it acts as a heat pump.
Send a current through a Peltier and it will start pumping
heat from one side to the other. Reverse the current and the
hot and cold side reverse as well.
That effect is used in portable coolers, where you can keep
cans (relatively) cool while plugged into your car 12V outlet
and you can even switch it to heating, which usually has a
poor effect, but nevertheless these are amazing devices
with efficiency well above 100%.

Before you go off on a rant about preservation of energy,
with efficiency, I mean that the output of heat is larger
than the amount of energy put in the device, because of
the pumping action. If the difference in temp between the
two sides is not too great, this device can easily deliver
50W of heat while only consuming 10W of electricity, by
pumping 40W of heat from ambient.

To generate electricity with them is possible, but very
inefficient, due to the large losses in heating and
cooling the two sides.
If you already have a large heat generator and plenty of
cool ambient, like in a driving ICE car, then you can
create some electricity the way you described, but
running an alternator is much cheaper and more efficient.
One place where I have seen the Peltier find some kind of
interesting application is a gas-powered night lamp, where
the excess heat creates a little electricity to power a
radio.

Regards,

Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
Email: [email protected] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [email protected]
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-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Jeff Shanab
Sent: Monday, October 08, 2007 7:36 PM
To: [email protected]
Subject: Re: [EVDL] Magnetic Shock Absorber & EV

Danny said "Peltiers are thermocouples."

Here is a clarification from http://www.its.org/node/3767

Effect 1 is what I was refering to as thermocouple. The idea I had was to take strips of iron and copper and create a long accorian folded isolated thermopile that mounted on the exhaust manifold. Wide strips for current electrically in series for a higher voltage.

Effect # 3 is what I refer to as a peltier, in that it takes 2 complimentary junctions of special materials.


International Thermoelectric Society.

Whilst it is generally accepted that there are only three thermoelectric effects, it is in fact possible to describe four.

The four thermoelectric effects, listed in chronological order of their discovery, are:

Effect 1 - If two different conductors are joined and the two junctions are maintained at different temperatures, an electromotive force is developed in the circuit.

Effect 2 - If a current flows in a circuit consisting of two different conductors then one of the junctions is heated and the other is cooled.

Effect 3 - When a temperature difference exists between two points in a single electrical conductor an electrical potential is established between the points.

Effect 4 - If a current passes through a conductor in which a temperature gradient exists, this current causes a flow of heat from one part to the other.

These effects are very closely related. Indeed, each of them represents a reversible effect whereby effects 1 and 2 are the reverse of each other, and effects 3 and 4 are similarly the reverse of each other.

Thomas Johann Seebeck first identified Effect 1 in 1821. He spent the rest of his scientific career measuring the size of this effect for different pairs of dissimilar conductors in contact with each other.
Seebeck died in 1831.

In 1834 Jean Charles Athanase Peltier first identified Effect 2, the reverse of Effect 1. Peltier died in 1845.

Significantly later (around 1854-1855), William Thomson first deduced and demonstrated BOTH of the effects numbered 3 and 4.

Starling and Woodall partly describe Thomson's contribution thus (from "Physics", Longmans, 1950):

<snip>

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