3,
Paper maps
Insight to designing your own circuit maps to be place on top of your prototyping boards to help you in making your circuits right, and spread knowledge to others!
Fabric Maps
For an introduction to soft circuits & electric couture
1. Basic light, switch & battery
1. Light Sensitive Circuit
Lights up when it's dark
Driving LED with constant current instead of voltage
http://www.sun-tec.ch/assets/s2dmain.html?http://www.sun-tec.ch/
MAXIM http://www.maxim-ic.com/app-notes/index.mvp/id/2197
Driving LE Ds? with Constant Current Port Expander Outputs
Abstract: This application note discusses techniques to drive LE Ds with the MAX 6956? and MAX 6957? I²C and SPI constant current static LED drivers. These techniques can be applied to other I/O expanders with constant current (internally current limited) open drain sink outputs. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
EPT http://www.ept.ca/issues/story.aspx?aid=1000357027
ON Semi’s constant current regulators (CC Rs?) simplify LED drive circuitry
Light Emitting Diodes (LE Ds) have become the de facto standard light source in electronic equipment today. Engineers are faced with designing LED drive circuitry in a variety of applications ranging from simple status indicators to sophisticated signage systems. This article focuses on the Constant Current Regulator (CCR) product from ON Semiconductor, which allows for very simple LED drive using a minimum of external components. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
FUTURE-MAG http://www.future-mag.com/0710/071030.asp
Constant Current Switching Regulators are Better than Voltage Resistor Drive for LED Drive
For the design of an LED light system powered from a low voltage supply such as 1-, 2-, 3- cell battery sources, the total cost of solution, battery life, the battery energy utilization, reasonably constant luminous flux output, the light signature (color temperature), the solution size and the weight are some of the important considerations, in applications such as flashlights, signage and illuminations. Switched mode power supplies outperform a voltage resistor drive for the above concerns. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
NATIONAL SEMICONDUCTOR http://www.presseagentur.com/nsc/detail.php?pr_id=2404&lang=fr - National Semiconductor _ prix 4.50$ / commande de 1000
National Semiconductor présente le premier driver de LED du marché, à réserve dynamique, pour applications haute puissance
Contrôleur Power Wise? permettant d’optimiser le rendement, de simplifier la conception, et de réduire les coûts système
À la différence des drivers de LED haute luminosité classiques, qui pilotent chaque chaine de LED de manière indépendante, le driver de LED LM 3464? dispose de quatre canaux lui permettant de piloter jusqu’à 20 LED par canal, réduisant ainsi la complexité et le coût système.
La fonction de réserve dynamique du LM 3464 ajuste en dynamique la tension d’alimentation des LED, en asservissant l’alimentation au niveau le plus bas permettant d’atteindre le rendement optimum. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
http://www.instructables.com/id/How-to-drive-a-lot-of-LEDs-from-a-few-microcontrol/ introHow to drive a lot of LE Ds from a few microcontroller pins.
Using the fact that many microcontroller pins have three states (+V, GND, or “high impedence”, you can drive N*(N-1) LE Ds from N pins. So the little 8 pin microcontroller like a PIC 12 Fxxx? or an A Ttiny 11? can drive 20 LE Ds on its five available output pins, and still have one pin left for some kind of input. http://www.xilinx.com/support/documentation/application_notes/xapp805.pdf - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Circuit board done on a commercial PCB mill: http://www.neufeld.newton.ks.us/electronics/?p=475