diode as a battery

[vinay sharma]

i alwayes think of diode not woking as battery when it is having a
potetial barrier in it ? millman sayes if u try to use it for
supllying current to some load. as the temp of that resistor will
raise up to make that happen diode will have to cool off. &it
according to thermal equlibrium is not possilbe . but i say i can
there be in some other form of energy. take an example of lighting
bulb by potato. does there potato get cool off. plaese comment over
it.

 

[Alex Corscadden]

A battery doesn't necessarily need to cool down in order to heat up a
resistor. You're assuming that the only energy present in the system is
thermal. Batteries use a chemical reaction to produce current, ie, there is
a chemical potential. When the current generated by a battery passes
through a resistor the electrons lose energy in the form of heat. In the
case of a diode, the electrons lose energy both as heat and as photons of
light, which you probably can't see because they tend to be in the low
infrared regions. As to the potato cooling off, I doubt it would. Many
batteries actually heat up when being used, NiCds for example get quite
toasty when in use. This is the result of both the chemical reaction that
liberates the electrons and as a result of a battery's own internal
resistance. If you've ever played with an RC car with a 7.2V NiCd pack
you'll know just how hot they can get.

Alex

"vinay sharma" <talktovin@indiatimes.com> wrote in message
news:4ef47eae.0403200345.4a77f890@posting.google.com...

i alwayes think of diode not woking as battery when it is having a
potetial barrier in it ? millman sayes if u try to use it for
supllying current to some load. as the temp of that resistor will
raise up to make that happen diode will have to cool off. &it
according to thermal equlibrium is not possilbe . but i say i can
there be in some other form of energy. take an example of lighting
bulb by potato. does there potato get cool off. plaese comment over
it.