[ARC5] Carbon cartridge replacement circuit

[WA5CAB at cs.com]

Brian,

Although it smacks somewhat of angels and pin heads, I would have to agree 
with Richard.  If you connect a reasonably efficient transducer that 
converts the varying current back to sound, the sound should be as loud or a little 
louder than the sound that produced the varying current.  Which very 
definitely is not true of any other type of microphone.  


And to answer your other question, it would be a Class B.  

Also, NO amplifier produces more power out than power in.  That would 
require an efficiency greater than 100%.  

In a message dated 04/28/2017 07:41:52 AM Central Daylight Time, 
brianclarke01 at optusnet.com.au writes: 
> 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> 
> 

Robert & Susan Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480
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