# Incandescent Lamp

Incandescent lamp with temperature dependent resistance

**Libraries:**

Simscape /
Electrical /
Passive

## Description

The Incandescent Lamp block models an incandescent lamp, the key characteristic of which is that the resistance increases as the filament warms up.

Under the simplifying assumption that the rate of heat loss from the filament is proportional to temperature difference to ambient, the temperature of the filament is governed by

$$k{t}_{c}\frac{dT}{dt}={i}^{2}R-kT$$

and the filament resistance is governed by the following equation

$$R={R}_{0}\left(1+\alpha T\right)$$

where:

*R*is the initial resistance at turn-on (when filament is at ambient temperature)._{0}*T*is the filament temperature relative to ambient temperature.α is the resistance temperature coefficient.

*t*is the thermal time constant._{c}*k*is the heat transfer coefficient.*R*is the filament resistance.*i*is the filament current.

There are two parameterization options:

If you select

`Specify resistance values directly`

, the block uses values that you provide for filament resistance when on and at turn-on to determine the value for the heat transfer coefficient.If you select

`Specify currents`

, the block uses values that you provide for filament current when on and at turn-on to determine the value for the heat transfer coefficient.

### Faults

To model a fault in the Incandescent Lamp block, in the
**Faults** section, click the **Add fault** hyperlink in
the parameter that corresponds to the specific fault that you want to model. When the
**Create Fault** window opens, you use it to specify the fault properties.
For more information about fault modeling, see Fault Behavior Modeling and Fault Triggering.

The Incandescence Lamp block allows you to model an
electrical fault as an open circuit resistance. The block can trigger fault events
at a specific time. When in the open-circuit state, the lamp resistance is set to
be the value of the **Open-circuit resistance** parameter.

## Examples

## Ports

### Conserving

## Parameters

## Extended Capabilities

## Version History

**Introduced in R2012b**