Philips RC5 IR decoder using 12 leds -  . . .  [Bill Bowden, designer]

Photo Sensor Circuit -  Here's a circuit that takes advantage of the photo-voltaic voltage of an ordinary LED. The LED voltage is buffered by a junction FET transistor and then applied to the inverting input of an op-amp with a gain of about 20. This produces a change of about 5 volts at the output from darkness to bright light. The 100K potentiometer can be set so that the output is around 7 volts in darkness and falls to about 2 volts in bright light. . .  [Bill Bowden]

Photovoltaic switch disables unused LEDs -  03/18/04  EDN Design Idea   In many applications, it's desirable to disable LEDs used for system verification. Many options are available for the disabling function, including manual SPST (single-pole single-throw] switches, enhancement- and depletion-mode MOS. . .  [by Lance McBride, Monterey Bay Aquarium Research Institute, Moss Landing, CA]

PIC controlled Fading Eyes -  . . .  [Bill Bowden, designer]

PIC Digital Clock Timer -  This clock timer uses a PIC16F628 microcontroller to display 3 and 1/2 digit time and control an external load. The clock includes a calendar with leap year and optional daylight savings adjustments. The timer output can be set from 1 to 59 minutes and manually switched on and off. The clock also has a correction feature that allows an additional second to be added every so many hours to compensate for a slightly slow running oscillator. The oscillator uses a common 32. 768 KHz watch crystal and the frequency can be adjusted slightly with the 24pF capacitor on the right side of the crystal. . .  [Bill Bowden]

PIC Digital Timer (4 timed outputs) -  This circuit uses the PIC16F628 microcontroller to provide 4 timed outputs that can be programmed from 1 minute to 1 week. An extra 8 bit shift register (74HC164) is used for the 4 timer outputs and to display four additional indicator lights. . . .  [Bill Bowden, designer]

PIC Micro LED Projects -  Here is a neat PIC Project  that I created using the 16F84 chip and a neat little bi-color LED from Radio Shack. The LED can be red or green depending on the bias of the diode. By using two of the PORT B pins, I can control the bias of the LED. If the LED is on PORT B, Pin 0 and Pin 1, I can set Pin 0 HIGH and Pin 1 LOW, this would make. . .  Jason KE4NYV from Roanoke, Virginia]

PIC microprocessor drives 20-LED dot-or bar-graph display -  09/01/06  EDN Design Idea   Indicator circuit features low cost and minimal component count. . .  [by Noureddine Benabadji, University of Sciences and Technology, Oran, Algeria]

PIC16F84 LED Chaser -  There are several projects on this page. Please scroll down to find the LED Chaser. . . .  Jason KE4NYV from Roanoke, Virginia]

Picxie 2 8x8 Animated LED Signboard -  The firmware supplied incurrent sourcecode archive is VERY BASIC. I do intend to draw more patterns. However, a vast workload coupled with possible emigration has put finished firmware on hold. Please do go ahead and build this circuit though supplied firmware is fully functional. You can have hours of fun designing your own patterns and effects!UsesPIC16F84. . . .  [Lewin A.R.W. Edwards]

Plus And Minus DC Power Supply -  This is a classic example of a regulated DC power supply that produces both a positive 15v and a negative 15v from a 20vac wall adapter . . . [Hobby Circuit designed by Dave Johnson P.E.,  10/16/05]

Pocket Ignignokt LED display -  By now everyone's heard about the 2007 Boston Mooninite Scare. Unfortunately, as far as I know, no one has put any thought into mass producing more of these guys. Well, no more. Thom, a now-buddy of mine from Chicago, emailed me after he saw my Superbowl party window decoration to tell me that he thought it would be awesome to design a Mooninite PCB that could be built cheaply enough to be used as a throwie. So here it is. . . .  [© 2007 by Riad S. Wah[by]

Pocket LED Light -  An LED pocket light operates with only one cell of battery. . . .  [The Electronic Lives Manufacturing-presented by Chan]

Pocket Lightning Detector -  . . .  [electronic design by Lennie Zink]

Pocket white-LED torch is power efficient -  04/30/13  EDN Design Idea   This single white-LED torch can be housed in an empty glue-stick tube and has a long rechargeable-battery life. . .  [by Raju Baddi]

Pocket-Size Reading Lamp -  This mini reading light combines the advantages of lithium button cells and white LEDs. While white LEDs are super-bright, lithium cells are small in size and last long. . . .  [© EFY Enterprises Pvt. Ltd. All rights reserved]

PointLess LED Array-A 8 by 8 array displays something using POV -  . . . 

Police Lights -  These two circuits flash the left LEDs 3 times then the right LEDs 3 times, then repeats. The only difference is the choice of chips. . . .  [Designer's name is not given}

Pong in a 3D LED matrix -  If you have ever wanted to play pong on a three dimensional display, then this one is for you. There are 1, 000 white LEDs in the matrix that can refresh at a rate of 60 fps. . . . 

     PAGE   Next >>>>