[ARC5] Carbon cartridge replacement circuit

[Michael Hanz]

I'm not gonna get in the middle of this debate, but it occurs to me that 
there might be some semantic misunderstandings near the heart of it.  To 
try and make sense of the two positions:

Brian, can you imagine _any_ sense in which the energy transfer function 
of a carbon microphone transducer with a DC current flowing through it 
might be greater than 1, making adjustments for the equivalent energy 
levels of input acoustic energy and output electrical energy?   Richard, 
are you sure you mean power amplifier, as opposed to voltage amplifier, 
or current amplifier?

Enquiring (or inquiring) minds might be interested in an ensuing 
(respectful) discussion...

  - Mike  KC4TOS

On 4/28/2017 8:41 AM, Brian wrote:
> Well Richard,
> I would have to say, once again, that you have an interesting slant on 
> electronics theory. From which electronics degree college did you 
> graduate?
> What Class of amplifier do you think it is? A, B, C, D, G, H ???
> Actually, there is no power output from a carbon microphone, except in 
> terms of self-heating. All the power comes from the power supply 
> delivering varying current in response to the mic element's changing 
> resistance. Yes, there is power going into the mic transformer's 
> primary; but once again, that comes from the power supply, not the mic 
> element.
> There is no similarity to a vacuum tube, because there is no grid to 
> control current flow - in fact there is control at all, except in the 
> shape of the flares and wind buffering / filtering around the mic 
> element, altering its frequency and 3D response pattern. It is the 
> drive that is all mechanical, not the control. The nearest you could 
> define it as is a transducer, converting mechanical energy into 
> changes in resistance.
> By your definition, you would have to claim that a water tap was an 
> amplifier - the mechanical action of operating its valve varies a 
> powerful stream of water. I wonder if this is a Class A, B, C, D ... 
> amplifier? Maybe a hydro-electric generator is an amplifier, turning 
> the potential energy of the head of water into the dynamic energy of 
> electrical power?
> Wow, your last sentence that I have left here beggars belief - output 
> power of a valve is the variation in plate resistance?? So, P = delta 
> R? Hmmm.
> 73 de Brian, VK2GCE.
>
> On Friday, April 28, 2017 11:28 AM, Richard Knoppow said:
>
>     A carbon microphone is an amplifier because the power out is
> greater than the power in. The controlling force is the acoustic energy
> available to the diaphragm, the diaphragm in turn converts the acoustic
> energy to mechanical energy which moves one of the contacts with the
> resistance element. This in turn varies the voltage across the resistive
> element and varies the current applied to it. The input energy, as
> absorbed from the air, is a small fraction of a watt but the output can
> be very large depending on the dissipation of the carbon element. The
> action is rather like a vacuum tube which also acts as a variable
> resistor. The input power to the grid is very small compared to the
> output power from the plate the variation being in the effective plate
> resistance.
> <snip>
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