Switched Panel Indicator

Application

This circuit uses the Light Bulb as a 12 V front-panel status indicator controlled by an interactive switch. It is set up as an interactive operating point demo, so opening or closing the switch updates the steady-state table values and bulb brightness without running a time-domain waveform.

Design Context

A panel indicator is a simple load path: supply, switch, lamp, and return. The switch starts open so the demo opens with the lamp off; click SW1 closed to energize the indicator. The idealized lamp model is a 120 ohm resistor, so a 12 V source produces about 100 mA when the switch is closed.

Expected Behavior

With SW1 open, lamp current should be near zero. Click SW1 closed and current flows from V1 through the switch and LAMP1 to ground. The table should show about 12 V at the lamp node and about 100 mA of lamp current. Clicking the switch open again should reduce lamp current near zero and dim the bulb symbol.

Key Values

• Simulation mode: interactive operating point
• Supply: 12 V DC
• Lamp resistance: 120 ohm
• Switch state: starts open, click to close or reopen
• Expected closed-switch current: about 100 mA

Suggested Experiments

• Click SW1 open and closed and compare the live lamp current.
• Change the lamp resistance to model a lower-current or higher-current indicator.
• Lower V1 and observe how lamp current and brightness change.

Featured Component

The Light Bulb is a two-terminal incandescent-style indicator lamp represented as a resistive load with current-driven visual illumination.