how does a heat engine actualy produce electricity???

[Hydro-Cell]

having a bit of difficulty finding a propper answer.  im looking at these peltier devices and other solid state heat engines.  what i cant get my head round is how they produce power when there is a thermal gradient.

how can these devices convert heat to power??

any help on this would be great
cheers

[nightlife]

 Heat is vibrant as is electricity. They are both are a energy because energy is a vibrance. Everything is vibrant and everything is made up of vibrance. Heat is electricity as is electricity is heat. Just as a rock is electricity and electricity is a rock. I bet I lost you there. LOL

You can not produce heat or electricity, you can only release and or store them. They are forms of energy and you can not produce and or destroy energy. You can only transfere it from one form to another by either capturing and storing it untill you have the amount needed, or by releasing it from one from and utilizing it as it is released or transferring it from one form to another like from heat to electricity and or by storing what is released from one form untill you either have what you need and for later usages you may need it for.

Sorry about the brain teaser but it is good food for thought. If you think about it, you will see what I am saying and it will have answered your question.

[Hydro-Cell]

hi thanks for the reply, unfortunatly this doesnt answer my question.

i understand that energy is everything, and it can only be converted not made nor destroyed.

my question was how does a heat engine such as a peltier device actually work.

hot on one side cold on another so theres a gradient the bigger the gradient then the more power produced, i am guessing the heat its converted into electricity but how exactly? what happens in the peltier device between this gradient and why is the gradient needed???

[sm0ky2]

Take a material (usually metals), such as steel - it has a particular vibration frequency that it naturally stays at, if you add heat it speeds this up, if you cool the metal down, this frequency slows down.

if you heat one end of of a metal, one end will be vibrating at a different frequency than the other until the temperature balances out across the piece of metal.  causes electrons to flow through the metal from the hot side to the cold side. one piece of metal by itself it is hard to detect this using normal electronic equipment. However, when you connect a second type of metal to the first one, you now have a changing vibration through both pieces of metal, the hot end will have more electrons at an excited state then the cold side, and thus a voltage/current are established between the two ends.
If the metal is 'short-circuited' the electricity aids in te heat-transfer and the system balances out quicker than you would expect,  but if you break the circuit and place an electric load in the middle of one of the metals, then you can exctract this electricity to use.

cooling the cold junction of the metals slows down the vibration in that end of the metal and lowers the number of electrons in an axcited state, this will increase the ammount of electricity that can be drawn out of the circuit.

[the_big_m_in_ok]

Hydro-Cell said:

...how can these devices convert heat to power??

I can't say for sure how that's possible, either.  The physics involved is a little beyond me.  But, have a look at these:

http://www.answers.com/topic/thermoelectric-effect

http://www.kelk.co.jp/english/useful/images/figure.gif

http://www.google.com/imgres?imgurl=http://www.blogcdn.com/www.engadget.com/media/2008/10/spin-seebeck-effect.jpg&imgrefurl=http://www.engadget.com/2008/10/09/researchers-say-spin-seebeck-effect-could-lead-to-new-batterie/&h=400&w=477&sz=36&tbnid=1niT1X8OhMW_ZM:&tbnh=108&tbnw=129&prev=/images%3Fq%3Dseebeck%2Beffect&hl=en&usg=__JMcRJrG7Qp9UgbPXANX7-YQDjyU=&ei=UIlaSt28KIGqswOAoeSDCw&sa=X&oi=image_result&resnum=4&ct=image


These 'Web addresses generally involve the Seebek Effect, and to some extent, the Peltier Effect.  They might be what you're looking for.

.

--Lee