Proa

These properties caused this device has long battery life and low power strain. Another features that this device has are protecting the battery and LED from overloading, trouble free operation such as overtemperature, over voltage, time-out function, undervoltage lockout, and feedback shorted protection.

The LM3570 evaluation board has a chip enable pin (active high logic) as well as a PWM (active high logic) pin which allows current sources to be turned on and off without completely disabling the part..The LM3570 is capable of supplying up to 80mA of current split between the regulated current sources and VOUT. The LM3570 comes in National’s LLP-14 package.

LM3433 is an adaptive constant on-time DC/DC buck constant current controller designed to drive a high brightness LEDs (HB LED) at high forward currents. It is a true current source that provides a constant current with constant ripple current regardless of the LED forward voltage drop. The board can accept an input voltage ranging from -9V to -14V w.r.t. GND. The output configuration allows the anodes of multiple LEDs to be tied directly to the ground referenced chassis for maximum heat sink efficacy when a negative input voltage is used.

To startup the Evaluation board, set the EN1 jumper and EN2 jumper to the “OFF” position, apply power to the board, and then move the EN jumper(s) to the “ON” position. This is the expected startup operation in the typical application where VIN is tied to a voltage rail and the EN pins are controlled via logic signal.

The LM3432 is a 6-channel high voltage current regulator which provides a simple solution for LED backlighting applicationsand the LM3430 is a companion device to supply high voltage required to drive serially connected LED strings. The LM3430 and the LM3432 provide a complete solution to most HB-WLED backlighting applications for notebook and PC monitor. In this application note, a typical example for a solution to drive six strings of twelve LEDs in series running at 20mA per string is described in details.

The LED WEBENCH® online design environment predicts and simulates the response of an LED to constant current while taking into account several potential design parameters that are new to designers of traditional switching regulators.

The output power of the modules are approximately 220W to 250W into 8? and 350W to 400W into 4?. Complete documentation for the amplifier modules can be found in the documents listed below. AN-1850 LME49830TB Ultra-High Fidelity, High-Power Amplifier Reference Design Although the power supply design is specific to the amplifier modules the concepts and circuit design may be used for any power supply purpose. The power supply is an unregulated design with an option to allow connection to either 120V or 240V mains. The design uses toroidal transformers, a fully integrated bridge, and various rail capacitors for ripple voltage reduction, noise suppression, and to act as high current reservoirs. Additional circuitry to control inrush current on power up and power up/ down Mute control are also included.

The topics discussed inside the application note including the introduction, overview, schematic and design, power supply, additional circuit, inrush current control, mute control, constant brightness LED circuit, summary, and many more.

It consists of only few components. IC LM3915 converts the audio analog voltage and display it to the LED. Here is the schematic :

Parts list :

•     Resistor R1 : 1k2
•     Resistor variable R2 : 10k
•     IC : LM3915
•     LED indicator LED1-LED10 : LED 5mm
•     12V power supply

It is a charge pump design. This is where a capacitor (electrolytic) is allowed to charge and is then raised higher and allowed to discharge into a load. The load sees a voltage that can be higher than the supply.