Novice Help AC DC Loadlines 6J5

I'm with John, what's the AC about eh?

It'll be at least half due to the plate half-wave rectifying the input. Depending on the circuit (and how you measure it) it may be anywhere from peak value, to a nonlinear middle point, or negative. (The nonlinearity being how the tube responds according to a 3/2 power law, as opposed to assuming the tube is a constant resistance = Rp while forward biased.)

Tim

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Howdy,

I'm looking for some help. Why when I use an AC plate supply(250VAC/RMS), are the voltage values in the circuit different than when I use a DC plate supply(250VDC) in the same circuit. The grid supply is -4VDC and I've got a 25K sense resistor in series to the plate(10ma of current). All the numbers using DC calculate out just fine. When I use an AC supply, voltages are different. TIA.

GP53

John,

In order to curve trace this circuit on a scope, an AC supply is used as a sweeping voltage. One leg of 250VAC secondary to anode, and the other though the sense resistor, then to the cathode.

Alan

John Fields wrote: