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Nixie-Clock using Neon Lamps to form Logic Gates - The above shows my home-built digital clock. it uses Nixie-tubes for readout. in contrast to most other nixie-clocks being built these days, my clock does not use any transistor or IC for driving the tubes. instead, the driving logic is built from neon lamps, together with resistors, capacitors and silicon diodes. __ Contact: pa3fwm @ amsat.org
Nixie-Tube Clock - This is a my nixie-tube clock built 8 years ago. __ Designed by The Electronic Lives Manufacturing-presented Chan
Novel PICAXE LED Chaser Clock - it's got hands to indicate hours, minutes and seconds, plus chaser LEDs that stop and freeze at the seconds hand__ SiliconChip
Off-the-shelf watchdog serves in a pinch - 01/07/99 EDN Design Ideas: The performance of the watchdog circuit in Figure 1 may not match that of a dedicated watchdog circuit, but this circuit is heLPFul when the only watchdog in the lab doesn’t meet your design’s temperature requirement and when you are in a hurry to finish a prototype Page includes several designs. Scroll to find this one Design by Giovanni Romeo, Istituto Nazionale di Geofisica, Roma, Italy
Old-Dog 555 Learns Six New Trick - 05/11/95 EDN Design Ideas: The circuits in Fig 1 invert the ubiquitous 555 timer's operation. The circuits' output polarities are the inverse of conventional 555 timers'. The circuits' output duty cycle is exactly 50%. Further, you have a choice of open-collector or totem-pole output-or both. And you can feed the timing capacitor from a negative current source referenced to the circuit's common. Design by James Keith, IMD Fincor Electronics Division, York, PA
On/Off Flip/Flop Circuit with Automatic Timeout - This circuit is ideal when a device needs to be turned on and off with a single pushbutton switch, but also needs to turn itself off after some period of time. With the components shown, the output will stay on for only about 20 seconds. . . Circuit by David A. Johnson P.E.-May, 2012
On/Off Latch Circuit with 2 Second Delay - A Discover Circuits visitor needed a latch circuit which could operate using a power supply voltage ranging from 3v to 24v. He wanted to use a tiny pushbutton switch to turn on and off power to a load. However, he wanted a 2 second delay between the switch activation and the state change of the output. . . Circuit by Dave Johnson P.E.-June, 2013
On/off Pushbutton Switch with 30 Minute Timeout - I received an email from a Discover Circuits visitor. He wanted to control power to a LED camping light he was building. He wanted to turn the light on and off with a small pushbutton switch. He also wanted a timer so the light would not stay on longer than 30 minutes at a time. it seems that his kids often turned lights on when going to bed and then forgot to turn them off. . . Circuit by David Johnson P.E.-January, 2012
One Hour Timer - A simple battery operated one hour timer device with an audible warning. May be used as a parking meter timer. __ Designed by Andy Collison
One second Audible Clock - Accurate, finger-operated portable unit; 3 - 12V Battery supply __ Contact Flavio Dellepiane, fladello @ tin.it
One Second Time Base from Crystal Oscillator - The schematic above illustrates dividing a crystal oscillator signal by the crystal frequency to obtain an accurate (0.01%) 1 second time base. Two cascaded 12 stage counters (CD4040) form a 24 stage binary counter and the appropriate bits are gated together to produce the desired division. Using a crystal of some even multiple of 2 is desirable so that one stage of the counter automatically toggles every second which eliminates the need for the NAND gate and reset circuitry, however the circuit below illustrates using a crystal which is not an even multiple of 2 and so requires additional __ Designed by Bill Bowden
One Second Timebase - Here are the instructions how to get one-second (1hz) pulses from a broken quartz clock. This is a precision timebase generator that can be used in any project that needs exactly one-second pulses. (6/11/2006) Updated! __ Designed by Jose Pino
One-Shot Timer for Energy Saving Lighting - Note that the circuit is coupled directly to AC mains using the existing system in the building. A switch is used to start the timing and light one or more bulbs. The relay is powered from 12V and its contacts must outstand up to 1kW at 220V. __ Designed by Popescu Marian
On-Time Programmable Pulsed Solenoid Driver - The LTC6993 is a monostable multivibrator (also known as a one-shot pulse generator) with a programmable pulse width of 1μs to 33.6 seconds. The LTC6993 is part of the TimerBlox family of versatile silicon timing devices. A single resistor, RSET, programs an internal master oscillator frequency, setting the LTC6993’s__ Linear Technology/Analog Devices App Note, Oct 26th 2010
Op Amp Triangle-Wave Generator & SPICE simulation files - This signal generator gives you two waveforms for the price of one: a triangle-wave and a square-wave. What is the central component of this circuit? The integrator capacitor Ci__
Op-amp Astable Timer - An astable timing circuit made from the ubiquitous 741 op-amp. __ Designed by Andy Collison
Original Two-wire Game Show Time - Several Game Show timers included, scroll to find this one. The game show timer determines which contestant presses their button first by lighting a lamp and ringing a bell and the slower contestants are locked out. The circuit is convenient in that only two wires are needed to interconnect the stations and the wires may all go back to the base unit or they may be "daisy-chained" between stations. There is no electronic limit on the number of stations. The circuit uses a 24 volt power source and 12 volt lamps when built as shown but the experienced experimenter may scale these voltages along with the zener voltages if desired. if the SCR triggers when the power is applied or when the reset button is pressed, add a 0.1uF capacitor from anode to cathode. (A sudden increase in voltage across some SCRs can trigger them, especially if the gate impedance is high.) __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Ornamental Flashing LEDs - This circuit can flash three sets of LEDs with different levels of Flashing. it can be used as Ornamental displays. The circuit uses a simple Astable multivibrator built around the popular timer IC NE555. Resistors R1, R2 and capacitor C1 determines the output frequency. When the output becomes high, Red LEDs lights first. When __ Designed by D Mohankumar
Oscilloscope CRT Clock - Apparently i'm in the shameful habit of making clocks in my spare time. First it was the Weston voltmeter clock, and then "Nixie 1, " a single-digit Nixie clock. Since soon after finishing the latter, I'vebeen daydreaming about making a clock out of an electrostatic deflection CRT—the kind of thing you find in an oscilloscope. Given that I'vejust come across some free time in the form of Christmas vacation 2005, I decided to make one of my own __ Designed by © 2007 Riad S. Wahby
Overheat Detector Alarm Switch - At the heart of this overhead detector (fire alarm) circuit is a precision integrated temperature sensor type LM35 (IC 1) , which provides an accurately linear and directly proportional output in mV, over the zero to +155 degrees C temperature range. This can be used as part of fire smoke detectors but do not use it as a home __ Designed by Popescu Marian |
