Does anyone know about the parameters required by B2 Spice subcircuit for a SE output tranformer?
The ones that puzzle me are:
1) primary winding inductance, series
2) primary inductance, parallel
as default values for a typical 8K transformer are
1) 0.04469602
2) 44.6074636
Thanks in advance
The ones that puzzle me are:
1) primary winding inductance, series
2) primary inductance, parallel
as default values for a typical 8K transformer are
1) 0.04469602
2) 44.6074636
Thanks in advance
If B2 is like 3f4, I've had deadly accurate results by just using impedances:
1) 0.008
2) 5
...and a coupling coefficient of .990 to 0.995 (unless your modelling a Hammond 16xxSE series, then it's 0.998)
Figure your coupling out by using sweep across the audio range and adjust for real-life specs.
1) 0.008
2) 5
...and a coupling coefficient of .990 to 0.995 (unless your modelling a Hammond 16xxSE series, then it's 0.998)
Figure your coupling out by using sweep across the audio range and adjust for real-life specs.
I'm dumb about spice, but the primary of an OPT consists of:
(higly simplified !)
1- A resistance wich represents the reflected secondary.
2- An inductance in parallel thats depends of the size of the iron core and the number of turns for the primary.
3- A capacitance in paralell due to the proximity of the primary and secondary windinds.
4- An inductance in serie wich represents the imperfections of coupling betwenn primary and secondary (because they incresase with frequency).
5- A resistor in serie wich represents the resistance of the windings. The primary can be measured directly, but the secondary measured must be multiplied by the turn ratio (wich is the square root of the impedance ratio)
Parameter 1 is easy to compute, knowing the load (RL) applied at the secondary and the impedance ratio (Zr) as = RL x Zr.
For a 1640SE, it is 1250 Ohms when loaded at nominal value.
Parameter 2 is 25 Hy and parameter 5 is 90 Ohms.
From http://www.hammondmfg.com/1627.htm
Other are not listed, a pessmistic guess would be 1000 pF for parameter 3 and 10 mHy for parameter 4.
Withe those values, the actual hi frequency response will certainly be better than simulated !
Yves.
(higly simplified !)
1- A resistance wich represents the reflected secondary.
2- An inductance in parallel thats depends of the size of the iron core and the number of turns for the primary.
3- A capacitance in paralell due to the proximity of the primary and secondary windinds.
4- An inductance in serie wich represents the imperfections of coupling betwenn primary and secondary (because they incresase with frequency).
5- A resistor in serie wich represents the resistance of the windings. The primary can be measured directly, but the secondary measured must be multiplied by the turn ratio (wich is the square root of the impedance ratio)
Parameter 1 is easy to compute, knowing the load (RL) applied at the secondary and the impedance ratio (Zr) as = RL x Zr.
For a 1640SE, it is 1250 Ohms when loaded at nominal value.
Parameter 2 is 25 Hy and parameter 5 is 90 Ohms.
From http://www.hammondmfg.com/1627.htm
Other are not listed, a pessmistic guess would be 1000 pF for parameter 3 and 10 mHy for parameter 4.
Withe those values, the actual hi frequency response will certainly be better than simulated !
Yves.
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