Here's an experiment that will convince the doubters: grind the top off a TO3 device on a heatsink. Aim an IR detector at the chip. Run a 10 Hz (or 5 Hz or whatever) signal through it. Do you see that signal at the IR detector?
Here is another experiment: draw schemo, take soldering iron, breadboard, measure. 😎
SY, if you go from tubes to transistors, it is another can of worms. Try it then come back. 😀
SY, if you go from tubes to transistors, it is another can of worms. Try it then come back. 😀
OK, interesting idea, but an LF sine wave might be my choice. I'd rather use something with more dynamics, on the order of 20-30dB peak over average like a good recording.
With that signal I'm not sure what I'd be looking for, thermally.
But I'll consider TL's point, that hot IS different, tho not because of thermal distortion. Too bad he won't discuss it here.
Which ones?
IR detectors have a very high bandwidth compared to the signals we're discussing- that's the only way that FTIRs can work.
Hi,
The ones you reference in your post # 281.
I take you performed the experiment before telling others to perform it?
Also, what the sensor does is one thing, you need to show whole system.
My IR based temperature measuring gun certainly is not fast enough to show a 10Hz sinewave...
Ciao T
The ones you reference in your post # 281.
I take you performed the experiment before telling others to perform it?
Also, what the sensor does is one thing, you need to show whole system.
My IR based temperature measuring gun certainly is not fast enough to show a 10Hz sinewave...
Ciao T
When did I say I published that?
The response time of IR sensors is well-characterized. I'm sure a resourceful fellow like you can find the basic literature. Your gun is not an appropriate tool, but could be modified as such pretty easily.
The response time of IR sensors is well-characterized. I'm sure a resourceful fellow like you can find the basic literature. Your gun is not an appropriate tool, but could be modified as such pretty easily.
Silicon solar cells have a bandwidth of 20Khz or better. They are used as pickups for optical soundtracks on film. IR detectors pick up the remote control stuff that is even higher than that.
I just don't know what the signal would look like with high dynamic range music going thru a transistor. Could be fun to try.
I just don't know what the signal would look like with high dynamic range music going thru a transistor. Could be fun to try.
IR photodiodes are routinely used with 38kHz subcarrier systems. If you have a gun-type thermometer, the signal can be taken off the amplifier following the detector.
Can't edit...
If you take emitter followers, things are even worse. Since designers of transistor amps are stuck with voltage amplification paradigm, they are forced to set bias of output emitter followers by voltage between bases. For stabilization they use thermal feedback, that shows all usual stability issues. No need to measure temperatures, just measure currents, how they vary with signal and it's envelope.
Come to think of it, I have a couple of IR send/receive modules that send 4 channels of 48Khz/16 bit audio over the infrared. They must be pretty fast.
I'm not sure I understand you. Or perhaps you're not understanding me. Are you saying that experiments should not be proposed?
Hi,
Of course experiments should be proposed.
However, it is reasonable to expect of those proposing them to have actually carried them out themselves, if they claim that said experiments will provide proof of their position.
Anyway, from the above I conclude you did not carry out the experiment yourself and that your claim for the experiment "to convince doubters" is based on your belief in the outcome, rather than actually having carried out the experiment?
Ciao T
Of course experiments should be proposed.
However, it is reasonable to expect of those proposing them to have actually carried them out themselves, if they claim that said experiments will provide proof of their position.
Anyway, from the above I conclude you did not carry out the experiment yourself and that your claim for the experiment "to convince doubters" is based on your belief in the outcome, rather than actually having carried out the experiment?
Ciao T
Hear ya. I have an e-mu 192KHz, 24 bit acquisition and a hundred bucks of software. Beats the old Scientific Atlantic analyzers that were 200K in the 70's.
What I can't find is a really nice interpretation of a delayed sweep storage scope. I bought about three, and none of then are up to the task.
You may get a kick. many years ago I sent Nicolet, HP, and Tek running. I needed a pre-triggered two channel scope that could capture a half nanosecond half volt glitch. I could do in on phosphor with the Polaroid, but no one could do in electronically back then. Everyone was using clock jitter to get that kind of resolution. Circa 1980. I finally got the picture using two meter probes as a delay line and a 1/2 meter as the trigger.
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