Technical: Adding your own rectifiers

In this section, there are some instructions for adding your own rectifier types to the database. You will need to edit the rectifiers.txt file in the application directory, typically C:\Users\my_name\AppData\Roaming\psud2\rectifiers.txt. Don't forget to make a backup of the file first, in case the results don't work out as expected.

Rectifiers.txt file

A quick recap on the format of the data lines rectifiers.txt follows:

    * The format is:
    *
    * Name,Type,Voff,Vlaw,Vfac,Vpiv
    *
    * Type: SS (Solid state) or VT (Vacuum tube).
    * Dres: Internal resistance of diode
    * Vlaw: Va/Ia power law
    * Vfac: Va/Ia factor
    * Vpiv: Peak Inverse Voltage allowed
    * Ipks: Peak current allowed, single cycle (Amps)
    * Ipkr: Peak current allowed, repetitive (Amps)
    *

You can use the * character to indicate a comment, and blank lines are acceptable. An example data line is:

    *Name Type DRes Vlaw Vfac Vpiv Ipks Ipkr
    5AR4, VT, 0.000,1.5, 0.00396, 1500, 99, 99

Parameters in detail

Name: The name 5AR4 will appear in the rectifier list.

Type: The type is VT for vacuum tube - this does not have any bearing on the operation of the software at this time, but may be used in future releases to provide a more appropriate symbol for the device.

Dres: An internal resistance in ohms which is represented in series with the rectifier model, in this case 0 ohms.

Vlaw: The Va/Ia power law. This is the power ratio of Va to Ia, in this instance 1.5 means that the rectifier current is proportional to Va^1.5

Vfac: Voltage factor, used to factor the rectifier current after other calculations have taken place.

Vpiv: Maximum peak inverse voltage allowed.

Ipks/Ipkr: Provided for information only, required but only Ipkr is currently implemented. Use a high value of 99 or even 999 if you are unsure.

The model

The models is based on an almost perfect rectifier in series with a resistance. The model for the rectifier for situations where Va > Vk is:

This is the internal rectifier model to which consideration should be made for the series resistance Dres, if used.

For example, if the 5AR4 example above is used, and Va is 20V, then Ia = (20 ^ 1.5) x 0.00396 = 0.354A.

Adding your own models

This is best achieved by using a spreadsheet. Make up a simple calculation with three variables Va, Vlaw and Vfac. The result (Ia) should be calculated in accordance with the formula above. Select values which correspond to a number of points chosen on the data sheet.

Using more modern spreadsheets, it becomes easier as the information from the data sheet can be entered in for a series of points and use goal-seeking functions to obtain the parameters for Vlaw and Vfac.

Online database

There is now an online database of rectifiers at http://www.duncanamps.com/psud2/rect_list.php.