Pulse Voltage Source

Periodic square wave voltage source

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Libraries:
Simscape / Electrical / Sources
Simscape / Electrical / Additional Components / SPICE Sources

Description

The Pulse Voltage Source block represents a voltage source whose output voltage value is a periodic square pulse as a function of time and is independent of the current through the source. The following equations describe the output voltage as a function of time:

$$V_{out}\left(0\right)=V_1$$

$$V_{out}\left(TD\right)=V_1$$

$$V_{out}\left(TD+TR\right)=V_2$$

$$V_{out}\left(TD+TR+PW\right)=V_2$$

$$V_{out}\left(TD+TR+PW+TF\right)=V_1$$

$$V_{out}\left(TD+PER\right)=V_1$$

where:

• V₁ is the output voltage at time zero.

• V₂ is the output voltage when the output is high.

• TD is the time at which the pulse first starts.

• TR is the time that it takes the output voltage to rise from V₁ to V₂.

• TF is the time that it takes the output voltage to fall from V₂ to V₁.

• PW is the time width of the output pulse.

• PER is the period of the output pulse.

The block determines the values at intermediate time points by linear interpolation.

The specified values for PW and PER have the following effect on the block output:

• If both PW and PER are infinite, the block produces a step response at time TD.

• If PER is infinite and PW is finite, the block produces a single pulse of width PW and infinite period.

• If PW is infinite and PER is finite, the block produces a step response with pulses of width TR to a value V1 every PER seconds.

• If PW > PER, the block produces a step response with pulses of width TR to a value V1 every PER seconds.

Examples

MOSFET Fault in Buck Converter

How a fault may be applied to a MOSFET in a power converter in order to explore the operation of protection circuitry. After the MOSFET becomes faulted, the crowbar circuitry is activated in order to clamp the output voltage across the load and eventually to cause the fuse to blow.

• Open Model

Ports

Conserving

+ — Positive voltage

electrical

Electrical conserving port associated with the pulse voltage source positive voltage

- — Negative voltage

electrical

Electrical conserving port associated with the pulse voltage source negative voltage

Parameters

Initial value, V1 — Initial output voltage

0 V (default)

Value of the output voltage at time zero, in V.

Pulse value, V2 — High output voltage

0 V (default)

Value of the output voltage when the output is high, in V.

Pulse delay time, TD — Pulse delay time

0 s (default)

Time at which the pulse first starts, in s.

Pulse rise time, TR — Pulse rise time

1e-9 s (default) | nonnegative scalar

Time it takes the output voltage to rise from the Initial value, V1 value to the Pulse value, V2 value. The value must be greater than or equal to 0.

Pulse fall time, TF — Pulse fall time

1e-9 s (default) | nonnegative scalar

Time it takes the output voltage to fall from the Pulse value, V2 value to the Initial value, V1 value. The value must be greater than or equal to 0.

Pulse width, PW — Output pulse time width

Inf s (default) | positive scalar

Time width of the output pulse. The value must be greater than 0.

Pulse period, PER — Output pulse period

Inf s (default) | positive scalar

Period of the output pulse. For the default value, Infs, the block produces a single pulse with an infinite period.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2008a