[Amps] EIMAC Confusion

DF3KV@aol.com DF3KV@aol.com
Wed, 13 Nov 2002 09:34:53 EST


> I am  a Solid State kind'a guy. There, things are relatively simple. TOTAL
> DEVICE DISSIPATION (TDD) is DCV times DCI`. The ratio between TDD and OUTPUT
> POWER  (OP) defines the
> efficency of the device. For example a 100W TDD transistor delivering 50W OP
> is sayd to have
> a 0.5 (or 50%) efficency.
> Here, in the Tube world it gets a bit more complicated as I have to contend
> with "parasitic" sources (like the filament and eventual grid source(s) )
> and there is no explicit text that I found yet that will explain it's
> (their) contribution to the TDD parameter.
> 
> 
> 
> Mark
> 
> 

Hi Mark,

Total device dissipation is never DCV time DCI, that is total consumption 
(input).
The total dissipation is the consumption minus output power, of course this
dissipation includes conductor losses.

Efficieny is (output-power/Input-power) * 100%

Regarding tubes:

Dissipation is always given only for the single electrode by the tube factory,
like  plate dissipation, screen dissipation, grid dissipation
The total of all dissipations+heater power has to be calculated for blower 
selection.

73
Peter





73
Peter


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