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 putfinished firmware on hold. Please do go ahead and build this circuit thoughsupplied firmware is fully functional. You can have hours of fun designing your own patterns and effects!UsesPIC16F84 __ Designed by Lewin A.R.W. Edwards Pinewood Derby Finish Line Lights - The finish line circuit below detects the first of three cars to cross the line and illuminates a 25 watt 120 VAC lamp indicating the winning lane. Three photo transistors are used which can be embedded into the track with a light shining down onto the finish line so that as the car crosses over the sensor, the light is blocked, activating the relay and lighting the lamp for the appropriate track. __ Designed by Bill Bowden
PLL-based converter controls light source - EDN-Design Ideas July 2, 1998 [ NOTE
: File has multiple design, scroll for this one.] Using the circuit in Figure 1, you can digitally control the light intensity of a lamp. The control loop is based on a PLL, in which the VCO comprises a light-to-frequency converter (TSL220) coupled to a light source that derives its drive from a switching regulator (L4970A) . The output of the phase/frequency comparator (4046) serves as the control voltage for the switching regulator. The control voltage is proportional to the frequency error between the reference frequency (fREF) and the signal frequency (fIN) coming from the light-to-frequency converter. Design by Masso Gottardi, ITC-IRST, Trento, Italy
Pocket LED Light - An LED pocket light operates with only one cell of battery. __ Designed by The Electronic Lives Manufacturing-presented Chan
Pocket Lightning Detector - Schematic + Info + pictures __ Designed by Lennie Zink
Pocket stroboscope - This circuit is a mini storoscope which you can make so small that it can fit into your pocket. The circuit is not very powerful, but is works out of two small 1.5V batteries for an hour constantly and maximum flash rate. The flash rate is variable from zero to about 10 Hz. Quite nice small device to have with you in parties to gain attention __ Designed by Tomi Engdahl
Pocket white-LED torch is power efficient - 04/30/13 EDN-Design Ideas This single white-LED torch can be housed in an empty glue-stick tube and has a long rechargeable-battery life. Design by Raju Baddi
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. __ 555-Timer
Porch Light Slave Switch - This circuit turns on the porch light when a passive IR security light is activated. __ Designed by Andrew R. Morris
Porch Light Switch - This circuit will activate a relay when light falls to a preset level. Light level can be adjusted with VR1 and the relay contacts may be used to operate an external light or buzzer. __ Designed by Andy Collison
Portable Lamp Flasher - Here is a portable, high-power incandescent electric lamp flasher. It is basically a dual flasher (alternating blinker) that can handle two separate 230V AC loads (bulbs L1 and L2) . The circuit is...__ Electronics Projects for You
Portable Signal Wand - Flashing lights have varied applications. For example, travelers can use these as warning beacons on highways to catch the attention of the public in case of an emergency. Described here is...__ Electronics Projects for You
Power 220V Flashing LED - AC mains operated single LED flasher circuit, built using the popular CMOS
timer chip TLC555 is shown below. The whole circuit is powered directly by the grid supply of 230VAC through a capacitive potential divider and associated components. This minuscule Power LED Flashing circuit can be easily fit inside a very small __ Designed by T.K. Hareendran
Power Flasher (PAGE 113) - Suitable for alerting purposes. Drives 12V Car bulbs __ Contact: Flavio Dellepiane, fladello @ tin.it
Power-line outage flashes red alert - 06/13/02 EDN-Design Ideas This design idea expands on a circuit in a previous one to configure a power-outage detector with a flashing alarm (Figure 1, Reference 1]. The circuit plugs into a mains outlet and uses trickle-charged nickel-cadmium batteries. The green-LED monitors the presence of line voltage. The BZV55-C4V3 zener diode, D1 protects the batteries against overvoltage Design by Vasiliy Borodai, Zaporozhje, Ukraine
Power-Off Time Delay Relay - The two circuits below illustrate opening a relay contact a short time after the ignition or ligh switch is turned off. The capacitor is charged and the relay is closed when the voltage at the diode anode rises to +12 volts. The circuit on the left is a common collector or emitter follower and has the advantage of one less part since a resistor is not needed in series with the transistor base. However the voltage across the relay coil will be two diode drops less than the supply voltage, or about 11 volts for a 12.5 volt input. __ Designed by Bill Bowden
Power-On Time Delay Relay - Here's a power-on time delay relay circuit that takes advantage of the emitter/base breakdown voltage of an ordinary bi-polar transistor. The reverse connected emitter/base junction of a 2N3904 transistor is used as an 8 volt zener diode which creates a higher turn-on voltage for the Darlington connected transistor pair. Most any bi-polar transistor may be used, but the zener voltage will vary from about 6 to 9 volts depending on the particular transistor used. Time delay is roughly 7 seconds using a 47K resistor and 100uF capacitor and can be reduced by reducing the R or C values. __ Designed by Bill Bowden
Preheat starter for electronic ballast - 10/04/01 EDN-Design Ideas Electronic ballasts for fluorescent lamps use various techniques to turn on the bulbs. The design usually involves a compromise between turn-on voltage and lamp life because the two are inversely related. One way to reach a reasonable compromise is to initially allow Design by Arthur E Edang, Don Bosco Technical College, Mandaluyong City, Phillipines
Programmable LED - Alex Inspired by various LED Throwies, blinking LEDs and similar instructables I wanted to do my version of an LED controlled by a microcontroller. The idea is to make the LED blinking sequence reprogrammable. This reprogramming can be done with __ Designed by Radio LocMan
Programmable LED Flashers - LED goes to steady state after a preset number of flashes; Two simple, wide supply range operating circuits __ Contact: Flavio Dellepiane, fladello @ tin.it
Proximity Switch for 240VAC Lamps - Just wave your hand near it to turn the light on or off.__ SiliconChip
Pulsing Third Brake Light - The schematic consists of two 555 timer/oscillators in a dual timer configuration both setup in astable mode. When power is applied via the brake pedal, the brake light driver Q1 is switched on via the low-output pin 3 of IC2, and timer IC1 begins its timing cycle. With the output on pin 3 going high, inhibiting IC2's pin 2 (trigger) via D2, charge current begins to move through R3, R4 and C2. __ Designed by Tony van Roon VA3AVR
Pulsing third Brake lite for cars - Several years ago these flashers were introduced in the automotive industry as part of the third brake light and contained strobe lights (and strobing continuously for the duration of pressing the break pedal) but got abandoned almost immediately sometime later because of the 'strobe' effect it has on some people. This circuit has become obsolet since much better circuits are available these days without the 'lag' in between brakes caused by R4 and C3. One of the circuits is listed below __ Designed by Tony van Roon VA3AVR
Push-bike Light - Automatic switch-on when it gets dark; 6V or 3V battery operation __ Contact: Flavio Dellepiane, fladello @ tin.it
Pushbutton Controlled Up/Down Ramping Light - There are times when you want a lamp to gradually change from dark to light and from light to dark, with each push of a pushbutton switch. The circuit below performs this control function using a flip/flop and a classic pulse width modulation or PWM. . . Circuit by David Johnson P.E.-March, 2009
Quiz - This project can be used for a quiz with up to 4 contestants (or teams) . Each contestant has a trigger push-switch and LED. When a trigger switch is pressed it lights the corresponding LED, sounds the bleeper and prevents the other trigger switches from workingtherefore showing which contestant was the first to press their switch __ Designed by John Hewes |