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TRIAC

Purpose

Ideal TRIAC with or without forward voltage and on-resistance.

Library

Switches

Description

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The TRIAC can conduct current in both directions. It is built using two anti-parallel thyristors and controlled by an external gate signal. The TRIAC is modeled by two ideal switches that close if the voltage is positive and a non-zero gate signal is applied. The conducting switch remains closed until the current passes through zero. A TRIAC cannot be switched off via the gate.

Parameters and Dialog Box

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The following parameters may either be scalars or vectors corresponding to the implicit width of the component:
Forward voltage
Additional dc voltage Vf   in volts (V) when one of the thyristors is conducting. The default is 0.
On-resistance
The resistance Ron   of the conducting device, in ohms (_O_  ). The default is 0.
Initial conductivity
Initial conduction state of the TRIAC. The TRIAC is initially blocking if the parameter evaluates to zero, otherwise it is conducting.
Thermal description
Switching losses, conduction losses and thermal equivalent circuit of the component. For more information see chapter Thermal Modeling. If no thermal description is given the losses are calculated based on the voltage drop von = Vf + Ron ⋅i  .
Initial temperature
Temperature of all thermal capacitors in the equivalent Cauer network at simulation start.

Probe Signals

TRIAC voltage
The voltage measured between the terminals.
TRIAC current
The current flowing through the device to the terminal with the gate.
TRIAC conductivity
Conduction state of the internal switch. The signal outputs 0 when the TRIAC is blocking, and 1 when it is conducting.
TRIAC junction temperature
Temperature of the first thermal capacitor in the equivalent Cauer network.
TRIAC conduction loss
Continuous thermal conduction losses in watt (W). Only defined if the component is placed on a heat sink.
TRIAC switching loss
Instantaneous thermal switching losses in joule (J). Only defined if the component is placed on a heat sink.