Zero Source Electronics

[xray]

I am looking for information on a circuit or physical configuration that having no source, however, can respond to a EMW (elecromagnetic wave) ping. The response would be a certain frequency output for a given temperature. Am I dreaming, is this information hgihly coveted and not available, or is it possible and information is available?
I am trying to get a temperature reading from an environment which reaches 300 deg. C. Automotive industry has brought about high temp. transistors but this requies a source. I am looking to implement a wireless no source device that can repond to an EMW ping and output a resosnant frequency that corresponds to temperature. Any help would be helpful.

Sincerely;

Cy drollinger

 

[IRstuff]

Biomedical ID systems are designed along these lines, but the range is extremely limited. Small chips can implanted in experimental animals. A reader is placed in proximity to the injection site and inductively couples to the embedded chip and it transmits the ID string from embedded chip.

BUT, the range is extremely limited. You'd need a truckload of transmitted power to power a sensor at moderate ranges.

TTFN

 

[xray]

I need only a short distance for transmission and the reciever is to be plugged into 120 AC less than a meter away from the sensor. Do you have any suggestion of biomedical companies working on such an ID system. I have searched google and found some hints of these systems but little to help my design.

 

[melone]

Why is a "source" so bad? I am fascinated with your question, but must admit, that I don't fully understand what your ultimate goal is. Are you looking for a wireless temp sensor that requires no power? Kinda like an ID badge that can lock and unlock certain doors via a scanning device?

 

[IRstuff]

Ranges are limited, although some of the larger ones seem to have several meter range and there is no obvious mention of temperature measurement, although that isn't technically that complicated, but perhaps, there's not enough demand:

http://www.avidmicrochip.com/answer.htm

http://www.identitrack.co.uk/animalid.htm

http://www.vernlib.com/vernrfid.asp

http://www.rfidwizards.com/rfidwiza...387894e9a24122c285256cea00023f43!OpenDocument

http://www.embedtechindustries.com/animal.htm

TTFN

 

[xray]

Melone I have only seen a few battery sources that will operate in the hundreds of C deg. infinite power solutions has a solid state battery that has UAH output, However, they are new and there stuff is expensive.

I have recently talked with an RF guy that says a possiblity would be an f To f transponder, anybody heard of such a thing. I have some research to do on this as an appoach.

IRstuff thanks for the websites will be checking in to those after this post goes in.

Thanx