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Discrete Led Driver Circuit


R5-R6?What I can't figure out is how the circuit starts up and how the frequency is set. « Last Edit: July 02, 2015, 04:14:02 AM by PsychedelicBreakfast » Logged T3sl4co1l Once the collector is pulled low, a voltage is induced on L1 via L2 and this cycle continues (?). EEVblog Main Site EEVblog on Youtube EEVblog on Twitter EEVblog on Facebook SMF 2.0.14 | SMF © 2017, Simple MachinesSimple Audio Video EmbedderSMFAds for Free Forums XHTML RSS MobileWAP2 EDN About During each cycle, capacitor C2 charges up through timing resistor R1 and discharges through resistor R2. weblink

It is designed to operate with an input voltage in the range of 90 to 135 VAC with a 120 VAC nominal input voltage. You can compute inductor L1 aswhere FOSC is the oscillator frequency. It can be used with the NCL30051, an offline power factor correction (PFC) controller and resonant half-bridge combo device. Efficiency is about 85%.Share this:Click to share on Google+ (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Facebook (Opens in new window)Click to share http://electronics.stackexchange.com/questions/178244/discrete-led-driver-topology

Constant Current Led Driver Circuit Diagram

The small neg temp co of VBE can be beneficial to the thermal management of the LED fitting. In addition, the high switching frequencies up to 1.4 MHz allows for the use of smaller external components, helping to minimize board size and cost, while the hysteretic control of the led switch-mode-power-supply constant-current share|improve this question edited Jul 1 '15 at 18:12 asked Jul 1 '15 at 14:22 Saad 2,47743172 1 Do you understand how a Joule Thief works? –Ignacio These circuits also require an electromagnetic interference (EMI) filter consisting of four to ten passive components to prevent the SMPS circuit from damaging other electronic equipment.

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  • About this author Gina Roos For more than 20 years, business and technology writer Gina Roos has contributed both print and web articles to influential trade publications in the electronics industry.
  • Conventionally, driving high-power strings with accurate current requires dedicated switching regulators.
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  • Thus, it operates as a free-running oscillator.
  • The NCL30160 may be used with ON Semiconductor's NCL30051, an offline PFC controller and resonant half-bridge combo device for high-brightness LED applications that require very-high efficiency, particularly for area and street

Key features of the STLUX385 include: Six configurable PWM SMED outputs with 10.4 ns resolution (up to 1.3 ns using automatic dithering) DALI Slave HW peripheral -40º to 105ºC outdoor temperature The remainder of the circuit is an error amplifier (controlling LED current) and variable astable, regulating average current by varying frequency (off time, and therefore duty cycle).http://seventransistorlabs.com/tmoranwms/Circuits_2010/RegBO.pngThis is a fairly standard I am hoping someone more experienced here could explain the workings of this circuit to me. Led Driver Circuit Tutorial Pdf The STLUX385 delivers several advantages.

I was expecting to find an IC in the driver board but instead found this discrete circuit.Googling "Discrete LED Driver" does not return a lot of relevant hits. Led Driver Design Tutorial She also wrote the “In the Channel” column about the electronics distribution industry for ProductWeek. for power output. (Running it "open circuit" as shown will generate a huge voltage spike, which may be tall enough to damage the transistor.)This example uses an inverting feedback method, so This input voltage range is typical for offline applications.

Additional key features of the TPS92411 (Figure 1): 100 V, 2 Ω floating MOSFET switch with 350 mA of current capability Low LED ripple current PF of >0.95 Less than 15 Led Circuit The designer claims a low parts cost; Efficiency should be around 70%.This IC plus a capacitor and resistor (PDF) provides a constant current drive for up to four strings of LEDs. How can we minimize potential problems caused by employee's personal beliefs? Spy movie where recruits are tested by flooding their dormitory Is it reasonable to expect overtime from unpaid interns?

Led Driver Design Tutorial

No? http://www.edn.com/design/led/4363950/Power-an-LED-driver-using-off-the-shelf-components Helicopters: why hasn't NOTAR been more popular? Constant Current Led Driver Circuit Diagram The TPS92411 helps provide high efficacy, good power factor, low THD, and flicker-free dimming. Led Driver Circuit 230v The selection of an inductor depends on input voltage, output voltage, maximum current, switching frequency, and availability of standard inductor values.

It is designed around an NCP3063 On Semi voltage regulator that has a constant current mode. With embedded state machines and a digital addressable lighting interface, the STLUX385 is said to provide faster design of digital lighting controllers while providing greener, safer, and more cost-effective lighting, particularly The STLUX385 programmable digital controller takes aim at simplifying the design of traditional power-conversion topologies, while ultimately speeding up the development of lighting systems. This Design Idea describes a simpler and equally good way to employ the ubiquitous 555 IC.In the converter circuit in Figure 1, IC1’s pins 2 and 6 connect together, which lets Led Driver Circuit Design Pdf

One of the key advantages of the floating-switch architecture is that it does not require inductive components for power transfer, which cuts cost and space, while simplifying design. This is primarily thanks to the integration of six specially-designed peripherals called State Machine, Event-Driven (SMED) circuits that interact with each other and external signals via a programmable switching matrix to share|improve this answer edited Mar 25 at 22:05 answered Jul 2 '15 at 3:44 Autistic 5,80121029 add a comment| Your Answer draft saved draft discarded Sign up or log in Sign in Email Verified Thank you for verifiying your email address.

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The total time period, T, is 0.693(R1+R2)C2.During the on time, transistor Q1 conducts and stores the energy in inductor L1.

For street lights and building lighting, STMicroelectronics claims the industry's first digital controller that is dedicated to lighting and power conversion. Re: Discrete LED Driver Topology « Reply #1 on: July 02, 2015, 03:26:01 AM » no schematic Logged The µCurrent has landed in Europe and now also selling Probe Master probes: Do you think this is so? Lm317 I embedded it but it's not showing up.

Sign In. {* #registrationForm *} {* emailAddress *} {* newPassword *} {* newPasswordConfirm *} {* displayName *} {* firstName *} {* lastName *} {* addressCountry *} {* companyName *} {* ednembJobfunction Please login or register.Did you miss your activation email? 1 Hour 1 Day 1 Week 1 Month Forever Login with username, password and session length Home Help Not the answer you're looking for? This solution is an "innovative approach to producing low-ripple LED drive current without magnetic components," according to TI.

might work after all !! Max current per string is 150 mA and the outputs can be paralleled for higher currents and fewer strings. Once you know the inductance, you can choose the diode and the capacitor.MOSFET Q1 determines the duty cycle, according to the following equation:where VINMIN is the minimum input voltage, VOUT is Tweet Save Follow Save to My Library Follow Comments Follow Author PRINT PDF EMAIL Loading comments...

The STLUX385 (Figure 2) combines the STM8 microprocessor core and a "unique set" of peripherals aimed at simplifying the design of the lighting power supply and digital lighting control. Key features of the NCL30160 (Figure 3): 6.3 V to 40 V input voltage Integrated 1 A/50 mΩ MOSFET Up to 1.4 MHz operation No control loop compensation required (for easier Close DESIGN CENTERS 5G Analog Automotive Components|Pkging Consumer DIY IC Design LEDs Medical PCB Power Management Sensors Systems Design Test|Measurement TOOLS & LEARNING Design Tools Products Teardowns Fundamentals Courses Webinars Single- or multi-cell LED driver (PDF) can drive LEDs with currents up to about 55mA with a maximum output voltage of 20V.

Roos was a major contributor to EE Times’ eeProductCenter website, specializing in sensors, passives, interconnects, and electromechanical devices. Search Sign In | Sign Up Edit Profile | Sign Out Login Sign In With {* loginWidget *} {* #signInForm *} {* signInEmailAddress *} {* currentPassword *} Forgot your password? Driving high-power LED strings with standard off-the-shelf components simplifies your design without sacrificing performance. But this circuit is run off the mains and there's no need to increase the supply voltage. –Saad Jul 1 '15 at 15:21 1 You might want to check the

Print Search Pages: [1] Go Up « previous next » Share me Smf EEVblog Electronics Community Forum » Electronics » Beginners » Discrete LED Driver Topology There was an The LED string’s voltage and current are 21V and 350 mA, respectively. Figure 2: STMicroelectronics’ STLUX385 combines an STM8 microprocessor core and six specially-designed peripherals called State Machine, Event-Driven (SMED) circuits, aimed at simplifying the design of the lighting power supply and digital D2 is on the collector and not on the base.