Cosine Waveform Load

The Cosine Waveform Load subcircuit models a time-varying load with a cosinusoidal current. At time=0, the load begins at the FINAL_CURRENT value and has a cosine function. The Cosine Waveform Load is not used in any test objectives, but you can change any load to a cosine load with a Cos() function call in a Load column.

Other similar loads include:

  • Sine Load - similar to the Cosine Waveform Load but with a sine function.

In this topic:

Model Name Cosine Waveform Load
Simulator This device is compatible with both the SIMetrix and SIMPLIS simulators.
Parts Selector
Menu Location
  • DVM > Loads > DVM Output Load - 2 Terminal
  • DVM > Loads > DVM Output Load - 3 Terminal
  • DVM > Loads > DVM Output Load - 4 Terminal
Symbol Library None - the symbol is automatically generated when placed or edited.
Model File SIMPLIS_DVM_ADVANCED.lb
Subcircuit Name
  • SIMPLIS_DVM_ADVANCED_LOAD_2T_COS
  • SIMPLIS_DVM_ADVANCED_LOAD_3T_COS
  • SIMPLIS_DVM_ADVANCED_LOAD_4T_COS
Symbols
Schematic - 2 Terminal
Schematic - 3 Terminal
Schematic - 4 Terminal

Parameters

The following table explains the relevant parameters.

Parameter Name Default Data Type Range Units Parameter Description
COEFFICIENT 0 Real     The damping coefficient for the cosinusoidal load current. If non-zero, the cosinusoidal load current amplitude will decay with a time constant equal to ???MATH???\frac{1}{\text{COEFFICIENT}}???MATH???.
FINAL_CURRENT 750m Real   A The peak or maximum current for the load. This can be a numeric value or a symbolic value, such as a percentage of full load.
FREQUENCY 10k Real min: > 0 Hz The frequency of the cosine waveform load
IDLE_IN_POP 0 Real 0 or 1   If set to 0, the load current during the POP analysis is set to the FINAL_CURRENT; otherwise, the load will be active during the POP analysis.
LOAD_NAME LOAD String n/a n/a Name of the DVM load. This name cannot contain spaces.
OFF_UNTIL_DELAY 0 Real 0 or 1   If set to 1, the load current will be ???MATH???\frac{1}{2}\left(\text{START_CURRENT}+\text{FINAL_CURRENT}\right)???MATH??? until the time specified by TIME_DELAY. If set to 0, the value of TIME_DELAY is interpreted as a phase delay.
PHASE_ANGLE 90 Real   ° The phase angle of the cosinusoidal waveform, used only if the USE_PHASE parameter is 1.
START_CURRENT 0 Real   A The minimum or starting current for the cosine waveform load. This can be a numeric value or a symbolic value, such as a percentage of full load.
TIME_DELAY 10u Real min: 0 s The delay before the cosinusoid starts. The load behavior before the TIME_DELAY is determined by the OFF_UNTIL_DELAY parameter.
USE_PHASE 0 Real 0 or 1   If set to 1, the load is configured to use the phase angle supplied by the PHASE_ANGLE parameter.

Testplan Entry

To set any managed DVM load to a Cosine Waveform Load subcircuit, place a Cos() testplan entry in a Load column.

The Cos()  testplan entry has the following syntax with the arguments taken from the list of parameters above.

Cos(REF, START_CURRENT, FINAL_CURRENT, FREQUENCY)
Cos(REF, START_CURRENT, FINAL_CURRENT, FREQUENCY, OPTIONAL_PARAMETER_STRING)
Argument Range Description
REF n/a The actual reference designator of the DVM load or the more generic syntax of OUTPUT:n where n is an integer indicating a position in the list of managed DVM loads
START_CURRENT n/a The minimum or starting current for the cosine waveform load. This can be a numeric value or a symbolic value, such as a percentage of full load.
FINAL_CURRENT n/a The peak or maximum current for the cosine wave load. This can be a numeric value or a symbolic value, such as a percentage of full load.
FREQUENCY min: > 0 The frequency of the cosine waveform load.
OPTIONAL_PARAMETER_STRING n/a Parameter string with any of the other parameters from the parameter table above*

*    If multiple parameters are specified, join the parameter key-value pairs with a space, as shown in the examples below. The order of the parameter names does not matter.

Examples

The following three examples set the first DVM managed load to a Cosine Waveform Load with a minimum current of 0A and a peak current of 1A. The timing parameters and the optional parameter strings are different in each example.

Note: In all of the examples below, the Load column is the first column in the testplan and, therefore, begins with the special three character sequence: *?@.

Zero Time Delay Example

Since the TIME_DELAY parameter is set to zero in this example, the cosine wave begins with the FINAL_CURRENT value of 1A at t=0.

*?@ Load
Cos(OUTPUT:1, 0, 1, 10k, TIME_DELAY=0)

The results of this testplan entry are shown below:

Time Delay Example

In this example, the TIME_DELAY parameter is set to 25us. Since the OFF_UNTIL_DELAY parameter is not specified, the TIME_DELAY value is interpreted as a phase delay. This results in the same waveform as a Sine Waveform Load.

*?@ Load
Cos(OUTPUT:1, 0, 1, 10k, TIME_DELAY=25u)

The results of this testplan entry are shown below:

Time Delay Example With OFF_UNTIL_DELAY=1

In this example, the TIME_DELAY parameter is set to 25us, and the OFF_UNTIL_DELAY is set to 1; therefore, for simulation times less than the TIME_DELAY parameter, the load current is 0.5A, as determined by the following equation: ???MATH???\frac{1}{2}\left(\text{START_CURRENT}+\text{FINAL_CURRENT}\right)???MATH???

*?@ Load
Cos(OUTPUT:1, 0, 1, 10k, TIME_DELAY=25u OFF_UNTIL_DELAY=1)

The results of this testplan entry are shown below: