[Ktechlab-devel] Simulating an amplifier.

[Alan Grimes]

Hello, I'd like to simulate an amplifier before buying many many
expen$ive components.

Naturally such a simulation will need to take into account many of the
parasitic properties of the components such as grid-plate capacitance,
or, for capacitors, ESR and ESL.

I'm going to need a transformer component too, actually the ability to
specify arbitrary transformers...

As an initial experament, I was trying to hack together a rectifier and
came across these problems:

1. To try to simulate a center tapped transformer, I tried to use a pair
of voltage sources, that didn't work because there was no way to specify
that the outputs on the two ends should be precisely out of phase.

2. I now have it running with one generator at 1hz, and I'm looking at
my rectifyer diode, it is showing both positive and negative voltage
swings on both sides! Very very wrong.

3. I put an ammeter and a load in the cirtuit, the left side of the
ammeter is showing the correct voltage, however the right hand side is
still pretending as if I still had the thing set at 60 hz!!! =(

4. I want to snub the rectifier with a 0.1 ufd capacitor but the sim
crashes, as was previously discussed...

The smallest capacitor in the design I'm working on is .33 pf. =P

To model an amplifier, I'm going to need parts for the basic common tube
types, (triode and pentode). For generality, it'd probably be best to
allow the user to enter custom values.

Popular triodes include: 300B, 2A3, 45, 71A, 845
Popular pentodes include: KT88, 6550.

(The tube I'm working with includes both a triode and a pentode, 6GV8 )

I am a skilled programmer so I'd like to contribute as much of the new
functionality as I can.

-- 
Don't let your schoolwork get in the way of your learning.

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