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LED Driver with Auto-Dimming for Thermal Protection Designer https://explore.partquest.com/node/275457 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/275457"></iframe> Title Description <p>This LED lighting example demonstrates the value of simulating both the electrical and thermal* aspects of power dissipating circuits together, simultaneously.</p><p>In this application example, a Vishay NTCS0603 Thermistor provides feedback of the enclosure temperature. This feedback is used to control PWM dimming of the LEDs, thereby limiting the internal temperature when operating at high external ambient temperature conditions.</p><p>This is a "Live" design, the user can change key parameter values and then run new simulations to see the results. These parameters include "r_mirror", the resistance of the current mirror that controls the capacitor charging rate of the 555 timer, and thereby set the PWM frequency. The user can also change "r_offset" that controls the temperature level at which the dimming operation begins. Finally, the user can set "r_iLED_set", to control the ON-state operating current of the LEDs.</p><p>----------------</p><p>* To reduce the time needed to simulate the transition and settling at 6 different temperature levels, all thermal time constants were reduced by approximately 1000x. The actual thermal response time constant of the NTCS0603 is approximately 3 seconds (depends on mounting), not 3 msec! Also, the enclosure thermal capacitance value would more likely be 3 (J/degC) instead of 3 (mJ/degC), giving a thermal time constant for the enclosure of 10 (degC/Watt) * 3 (J/degC) = 30 seconds. This time scaling does not affect the static relationship between the outside temperature and PWM dimming.</p> About text formats Tags 555 Timercurrent mirrorPWMLEDelectro-thermalNTCThermistorVISHAY Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
LED Driver with Auto-Dimming for Thermal Protection- Alain Designer https://explore.partquest.com/node/275433 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/275433"></iframe> Title Description <p>This LED lighting example demonstrates the value of simulating both the electrical and thermal aspects of power dissipating circuits together, simultaneously.</p> <p>In this application example, a Vishay NTCS0603E3103MT Thermistor provides feedback of the enclosure temperature. This feedback is used to control PWM dimming of the LEDs, thereby limiting the internal temperature when operating at high external ambient temperature conditions.</p> <p>This is a "Live" design, the user can change key parameter values and then run new simulations to see the results. These parameters include "r_mirror", the resistance of the current mirror that controls the capacitor charging rate of the 555 timer, and thereby set the PWM frequency. The user can also change "r_offset" that controls the temperature level at which the dimming operation begins. Finally, the user can set "r_iLED_set", to control the ON-state operating current of the LEDs.</p> About text formats Tags 555 Timercurrent mirrorPWMLEDelectro-thermalNTCThermistorVISHAY Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
led Designer https://explore.partquest.com/node/252342 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/252342"></iframe> Title Description About text formats Tags LED Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
Daytime running lights and sequential amber on Ford Focus ST Designer https://explore.partquest.com/node/245095 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/245095"></iframe> Title Description <p>Daytime running lights and indicator lights (switchback + sequential amber LEDs). First schematic is for Daytime Running Light that switch to indicator signal light and back again. Second is just indicator signal light with separate power source. Third is power just from Indicator light signal.</p> About text formats Tags DRL, daytime running lights, relay, car, headlightsLED Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
Astable multivibrator Designer https://explore.partquest.com/node/244901 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/244901"></iframe> Title Description About text formats Tags TransistorLED Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
ACME LED Driver - full flat schematic Designer https://explore.partquest.com/node/243518 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/243518"></iframe> Title Description <p>This schematic represents the behavior of the ACME AS123 LED Driver. It was used to create the "schematic-based model" of that part,</p> About text formats Tags LED LightingLEDACMEDimmer Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
simple circuit with LED and transistor Designer https://explore.partquest.com/node/223486 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/223486"></iframe> Title Description About text formats Tags TransistorLED Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
CLAP SWITCH Designer https://explore.partquest.com/node/216026 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/216026"></iframe> Title Description About text formats Tags LEDsoundCLAP Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
NPN controls high power LED Designer https://explore.partquest.com/node/213866 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/213866"></iframe> Title Description <p>Tests high power LED drive by an NPN transistor</p> About text formats Tags LEDpower led3W LED Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
CAT4104 LED Controller Application Example Designer https://explore.partquest.com/node/212976 <iframe allowfullscreen="true" referrerpolicy="origin-when-cross-origin" frameborder="0" width="100%" height="720" scrolling="no" src="https://explore.partquest.com/node/212976"></iframe> Title Description <p>This is an application example for an ON Semiconductor CAT4104 Quad Channel Constant Current LED Driver. It demonstrates the part's resistor programmable and independent current control for each channel, as well as its PWM dimming capability. By choosing the value of r_set from 768 Ohm up to 12 kOhm, the current in each channel is controlled from 175 mA down to 10 mA. That is, the channel current is 100 times the current in r_set, which is driven by an internal 1.2 V source from the CAT4104 "rset" pin. The LED strings can be driven by parallel channels to reach even higher string current levels.</p><p>For LED dimming, the CAT4104 "en_pwm" pin can be driven by a PWM signal. In this application circuit, that signal is provided by an LM555 timer module. The potentiometer setting controls the PWM duty cycle, and the element's total resistance value determines the PWM frequency. The initial potentiometer wiper ratio of 0.5 and resistance of 20 kOhm, gives a 50% PWM duty cycle at 500 Hz.</p><p>The LED string model, for which the user can select the number of LEDs in the string as well as the individual LED operating parameters, has an internal quantity that gives the "perceived" luminous output. This includes a 15 Hz Low-pass filter, to represent the light-averaging effect of the human eye. This is shown in the dark blue waveform. The user can explore the effect of changing the potentiometer settings, which in turn change the PWM characteristics, on the perceived light output. The initial LED parameters for this example represent a CREE XPCWHT-L1-R250-009E6.</p> About text formats Tags 555 TimerLEDCAT4104LM555 Select a tag from the list or create your own.Drag to re-order taxonomy terms. License - None -
