LED Lighting | PartQuest™ Explore

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Designer19

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11 years 7 months

1,833

designs

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Member of the PartQuest Explore Development Team. Focused on modeling and simulation of analog, mixed-signal and multi-discipline systems covering a broad range of applications, including power electronics, controls and mechatronic systems.

Description

This automotive electrical power distribution system example includes multiple vehicle sub-systems and components. It supports sizing analysis for wires and fuses, under both static and transient loading conditions. This includes multi-discipline (i.e. electro-thermal-mechanical) dynamic operations such as incandescent lamp in-rush current and motor start-up conditions. The example also demonstrates the special characteristics and design considerations needed for constant power loads, such as switching converters used in LED Driver circuits.

This system also uses a special “direction sensitive” current monitor model that can help identify sneak circuits (i.e. unintended current paths), such as the one found in the “door-ajar”, ignition switch, chime and dome lamp interconnect circuit. Challenge: See if you can find it before running the simulation!

After you run the simulation, a "Component Messages" window will pop up and show several problems with the system. These include a "reverse current detected" (i.e. current flow in the opposite direction from the expected) in the wire that carries current to the dome lamp to indicate a door is ajar. Current reversals are often due to a "sneak circuit" in design, which can lead to undesired function or behavior of the system. In this case, the reverse current is showing that if the driver puts the key in the ignition and turns on the dome lamp to read a map, the warning chime will sounds even though there are no doors ajar!

The other message indicates that the fuse supplying the flasher circuit has blown, shortly after the hazard flasher is turned on. Clearly this fuse is undersized to supply all 4 flasher lamps together, but operates fine with when just 2 are operated for normal turn signaling. You can try other operational conditions for this system to test for proper fuse sizing. For example, try changing the LED constant power pulse_value to 50W instead of 20W. You can also change the fan inertia to 200u Kg*meter^2, up from 100u. To fix the problem caused by the increase motor inertia (and correspondingly longer time transitioning for stall to normal operating load current), try increasing the fan fuse I^2*T value from 5 to 36, to represent the performance of a slower-blowing fuse.

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ACME AS123 LED Driver Schematic Model JSAE 2025

Designer241497

Member for

3 years 9 months

164

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6

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I'm a member of the PartQuest Explore Promoto.

Description

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ACME AS123 LED Driver with Dimmer Control JSAE 2025

Designer241497

Member for

3 years 9 months

164

designs

6

groups

I'm a member of the PartQuest Explore Promoto.

Description

The AS123 LED Driver from ACME Semiconductor (fictional) provides fully integrated PWM dimming and a programmable current set-point. This IC is specifically for automotive rear combination (tail/stop) lighting applications. It tightly regulates the desired string current under conditions of widely varying applied DC voltage.

The PWM dimming function, which switches the LED on and off at just over 300 Hz, is active when the line input pin is high and the "PWM_disable" pin is low (

The AS123 supports current programming using a single external resistor (see r_iset in the schematic). The resistor value can be selected to give the desired LED string current, using the following formula:

r_iset = 1.85/i_desired

The AS123 is capable of regulating up to 100mA per string continuously. Therefore the value of r_iset should be no less than 18.5 Ohms. The user can change this resistor value and run a new simulation, to see the effect of this change on the LED string current.

See a "functional block diagram" schematic model of the ACME AS123 here: https://www.systemvision.com/design/acme-as123-led-driver-schematic-model

-------------- End of Example Application Note ------------------

If you are a component supplier, this type of "Live Application Note" can help your potential customers better understand the features and benefits of your components.

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Copy of Low Current LED Drive using ACME AS123 - on Thu, 04/03/2025 - 15:51

Designer244467

Member for

2 years 8 months

329

designs

4

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Member of the PartQuest Explore development team.

Copy of Low Current LED Drive using ACME AS123 - on Thu, 04/03/2025 - 15:48

Designer244467

Member for

2 years 8 months

329

designs

4

groups

Member of the PartQuest Explore development team.

Copy of Automotive Electrical Power Distribution System - on Thu, 03/21/2024 - 09:31

Designer255208

Member for

1 year 3 months

2

designs

1

groups

Welcome to the community!!

Description

This automotive electrical power distribution system example includes multiple vehicle sub-systems and components. It supports sizing analysis for wires and fuses, under both static and transient loading conditions. This includes multi-discipline (i.e. electro-thermal-mechanical) dynamic operations such as incandescent lamp in-rush current and motor start-up conditions. The example also demonstrates the special characteristics and design considerations needed for constant power loads, such as switching converters used in LED Driver circuits.

This system also uses a special “direction sensitive” current monitor model that can help identify sneak circuits (i.e. unintended current paths), such as the one found in the “door-ajar”, ignition switch, chime and dome lamp interconnect circuit. Challenge: See if you can find it before running the simulation!

After you run the simulation, a "Component Messages" window will pop up and show several problems with the system. These include a "reverse current detected" (i.e. current flow in the opposite direction from the expected) in the wire that carries current to the dome lamp to indicate a door is ajar. Current reversals are often due to a "sneak circuit" in design, which can lead to undesired function or behavior of the system. In this case, the reverse current is showing that if the driver puts the key in the ignition and turns on the dome lamp to read a map, the warning chime will sounds even though there are no doors ajar!

The other message indicates that the fuse supplying the flasher circuit has blown, shortly after the hazard flasher is turned on. Clearly this fuse is undersized to supply all 4 flasher lamps together, but operates fine with when just 2 are operated for normal turn signaling. You can try other operational conditions for this system to test for proper fuse sizing. For example, try changing the LED constant power pulse_value to 50W instead of 20W. You can also change the fan inertia to 200u Kg*meter^2, up from 100u. To fix the problem caused by the increase motor inertia (and correspondingly longer time transitioning for stall to normal operating load current), try increasing the fan fuse I^2*T value from 5 to 36, to represent the performance of a slower-blowing fuse.

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Copy of Automotive Electrical Power Distribution System - on Mon, 11/13/2023 - 09:21

Designer251218

Member for

1 year 7 months

3

designs

1

groups

Welcome to the community!!

Description

This automotive electrical power distribution system example includes multiple vehicle sub-systems and components. It supports sizing analysis for wires and fuses, under both static and transient loading conditions. This includes multi-discipline (i.e. electro-thermal-mechanical) dynamic operations such as incandescent lamp in-rush current and motor start-up conditions. The example also demonstrates the special characteristics and design considerations needed for constant power loads, such as switching converters used in LED Driver circuits.

This system also uses a special “direction sensitive” current monitor model that can help identify sneak circuits (i.e. unintended current paths), such as the one found in the “door-ajar”, ignition switch, chime and dome lamp interconnect circuit. Challenge: See if you can find it before running the simulation!

After you run the simulation, a "Component Messages" window will pop up and show several problems with the system. These include a "reverse current detected" (i.e. current flow in the opposite direction from the expected) in the wire that carries current to the dome lamp to indicate a door is ajar. Current reversals are often due to a "sneak circuit" in design, which can lead to undesired function or behavior of the system. In this case, the reverse current is showing that if the driver puts the key in the ignition and turns on the dome lamp to read a map, the warning chime will sounds even though there are no doors ajar!

The other message indicates that the fuse supplying the flasher circuit has blown, shortly after the hazard flasher is turned on. Clearly this fuse is undersized to supply all 4 flasher lamps together, but operates fine with when just 2 are operated for normal turn signaling. You can try other operational conditions for this system to test for proper fuse sizing. For example, try changing the LED constant power pulse_value to 50W instead of 20W. You can also change the fan inertia to 200u Kg*meter^2, up from 100u. To fix the problem caused by the increase motor inertia (and correspondingly longer time transitioning for stall to normal operating load current), try increasing the fan fuse I^2*T value from 5 to 36, to represent the performance of a slower-blowing fuse.

About text formats