A Collection Of Standard Potentiometers Helmut Sennewald, V1.1 A new symbol "potentiometer_standard.asy" has been generated for all the new potentiometers. Put this file into the LTSPICE installation path lib\sym \... or into your working directory. The file "potentiometer_standard.lib" contains the X-subcircuits of all the potentiometers. There is a linear, log. and an arbitrary model. I have included the old model too. Put the file "potentiometer_standard.lib" into the folder ...\Progams\Ltc\SwCADIII\lib\sub or into the directory where your schematic "potentiometer_standard_test.asc" is. potentiometer : equivalent function to pot_lin, just the old symbol and model pot_lin : ideal linear resistance dependency pot_pow : ideal power function resistance dependency pot_plog : ideal positive logarithm function resistance dependency pot_nlog : ideal negative logarithm function resistance dependency potr_tab: arbitrary(table) based resistance dependency pot_piher_plog : pseudo logarithm function resistance dependency, Piher pot_radiohm_plog : measured pseudo logarithm fucntion resistance dependency, Radiohm LTSPICE have to be restarted before the new symbol can be used. The pot_pow, pot_plog and pot_nlog potentiometers need an additional reference value. This reference value pair specifies the slope of the ratio. Rtap: resistance at the refrence point Tap: position of the wiper at resistance Rtap How to select the model? Move the cursor over the potentiometer then click the right mouse button. Then the the model name and the parameters can be changed. The model file has to be loaded with a .include potentiometer_standard.lib statement to the schematic. * A Collection of Potentiometers * ============================== * Helmut Sennewald, 12/23/2003 V1.1 * * Models: * potentiometer old style LTSPICE potentiometer * pot_lin k*x * pot_pow x^k * pot_plog exp(k*(1-x)) * pot_nlog exp(kx) * pot_tab table(x) * pot_piher_plog piecewise linear, datasheet * pot_radiohm_plog piecewise linear, measured * * * 1 ____ 1.0=wiper * | * | | 3 * | |<---- wiper 0..1 * | | * Rtap | | Tap * | | * 2 ____| 0.0=wiper * * * RTOT = total resistance * WIPER = ratio of travel of the wiper * RTAP = reference resistance at wiper=Tap * It is needed only for pot_plog, pot_nlog and pot_pow. * RTAP is measured between pin-2 and wiper. * TAP = ratio of travel when Rtap is reached