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Timers and Counters Circuits

Timers & Counters:  #'s - A      B - D      E - L      M - S      T - Z


Last Updated: January 01, 2018 04:02 AM

Circuits Designed by Dave Johnson, P.E. :
Front Desk Service Beeper -  This device functions like a lobby desk service request bell.  A short beep is sounded whenever the large pushbutton on top of the device is pressed.  Once pressed, the device will not make another beep until at least 2 minutes of time has elapsed . . . Hobby Circuit designed by David A. Johnson P.E.-September, 2005

Garage Door Timer -  The circuit below is designed to automatically close a garage door, if it was left open for a long period of time.  A reed relay and magnet combination sense when the door is fully open.  An ultra low power voltage comparator oscillator and two 74HC4040 ICs are used to generate the time delay. . . Circuit by Dave Johnson P.E.-May, 2011

Laser Used as Vehicular Traffic Counter -  This is an illustration how a laser could be used to count traffic and measure the speed of each car passing through the sensor area. . . Circuit by David A. Johnson P.E.-January, 2007

Line Powered 60hz Clock Generator -  This circuit is connected to the 120vac power line and transfers 60Hz clock pulses to a logic circuit.  The optoisolator used provides 5000 volts of isolation between the power line and the logic side of the circuit. . . Circuit by Dave Johnson P.E.-February, 1999

Long Period Computer Watch Dog Timer -  This circuit uses a simple 4060 IC oscillator/timer that is reset periodically by a computer.  Should the computer fail to send a pulse, the output changes state.  The time can easily be set from seconds to hours. . . Circuit by David Johnson P.E.-January, 1998

Low Power Oscillators -  This page has two unusual two-transistor oscillators.  I set the component values for a low frequency application.  Both circuits draw only about 1 micro amp of current. . . Circuit by David A. Johnson P.E.-December, 2002

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-368-7747

Links to electronic circuits, electronic schematics, designs for engineers, hobbyists, students & inventors:

IC 555 Timer Tester -  This simple and easy-to-use gadget not only tests the IC 555 timer in all its basic configurations but also tests the functionality of each pin of the timer.  Once a timer...__ Electronics Projects for You

IC oscillator 1...30MHz using 74LS04 chip -  Ham Radio - V-U) HF AMPLiFiER - Schematic __ Designed by Guy Roels ON6MU

ICL7107-DigitAL LED AM METER -  Ammeter is a great addition to any Laboratory Power Supply as it will measure the current consumption and help you determine if there are any problems with the circuit that you are building or testing.  This amper meter is capable of measuring the current consumption up to 10A with selected 100mA, 10mA and 1mA accuracy.  __ 

ICL7107-DigitAL LED VOLTMETER -  This digital voltmeter is ideal to use for measuring the output voltage of your DC power supply.  it includes a 3.5-digit LED display with a negative voltage indicator.  it measures DC voltages from 0 to 199.9V with a resolution of 0.1V.  __ 

Ignition Timer -    NOTE: Must register on this site __ Designed by Published in Elecktor July/Aug, 2010

Increasing Output Current -  The 555 will deliver 200mA to a load but the chip gets extremely hot (12v supply).  The answer is to use a buffer transistor.  __ 555-Timer

Increasing Output Push-Pull Current -  Some 555's do not swing rail-to-rail when 200mA is being delivered and the chip gets very hot when trying to deliver 200mA.  The solution is to add a push-pull output.  The following arrangement has been chosen as it swings almost rail-to-rail but two faults need to be addressed__ 555-Timer

Increasing the Number of Outputs from a Clock Source using Low Jitter LVPECL Fanout Buffers  -  The EVAL-ADF4351EB1Z board uses the standard ADF4351 programming software contained on the CD that accompanies the evaluation board.  CiRCUiT EVALUATiON AND TEST, Getting Started The UG-435 user guide details the installation and use of the EVAL-ADF4351EB1Z evaluation software.  install the ADF435x software to PC by doing the following: __ Analog Devices from the Lab

Infrared Alarm Barrier -  This infrared alarm barrier can be used to detect persons passing through doorways, corridors and small gates.  The transmitter emits a beam of infrared light which is invisible to the human eye.  The buzzer at the output of the receiver is activated when the light beam is interrupted by a person passing through it.  infrared __ Designed by Popescu Marian

Infrared Object Counter -  This infrared object counter can be installed at the entry gate to count the total number of people entering any venue.  For example, it can be used at the railway stations...__ Electronics Projects for You

Infrared Remote Control Timer -  The circuit comprises two sections, namely, the transmitter section and the receiver section.  Fig.1 shows the IR transmitter section.  The astable multivibrator NE555 (IC 1) is used to generate a 10kHz...__ Electronics Projects for You

INSIDER V10 -  in-Circuit debugger, created by E.  E.  Atanasios Melimopoulos.  Updated Ver 1r1 __ Designed by Jose Pino

Interface LCD with ease -  04/27/00 EDN Design Ideas:  Alphanumeric LCDs find use in various embedded systems.  in these systems, Cs often lack i/O resources, so you must make optimum use of the available resources.  LCDs have a bus-oriented interfacing structure, which consumes 11 i/O lines (eight data lines and three control lines).  You cannot always afford to spare this many i/O lines.   __ Circuit Design by Bharat Mehta, Space Applications Center, Ahmedabad, India

Internet Time Display Module for the WIB -  Looking for a really accurate clock? This simple add-on board for the WiB (Web Server in A Box) displays the time and date, as gathered from an internet time server.  You can use it as a clock you never need to adjust and it can even be configured in the WiB to automatically adjust for daylight saving time.__ SiliconChip

Introduction to Time, Frequency & Modal Domains 5988-6765EN -  Application Note__ Aligent

Inverted 555 Timer -  Whenever I use the 555 timer, it seems that the output polarity is invariably incorrect, and the way the 555 functions, it normally cannot generate a duty cycle of less than 50% 90% yes, 10% NO!  This inverted 555 circuit generates duty cycles of less than 50%.  Everything works the same except for the polarity.  Why not simply __ Designed by Jim Keith

Inverting Level-Shift Has Negative Potential -  EDN-Design ideas -- 07/24/12    Shift clock logic levels to match the requirements of the driven device. __ Circuit Design by Chun-Fu Lin and Shir-Kuan Lin, National Chiao Tung University, Hsinchu, Taiwan; and Hui-Shun Huang, Jyi-Jinn Chang, and Tai-Shan Liao, National Applied Research Laboratories, Hsinchu, Taiwan

Isolated PWM (5% to 95%) Controller -  The LTC6992 is a silicon oscillator with an easy-to-use analog voltage-controlled pulse width modulation (PWM) capability.  The LTC6992 is part of the TimerBlox family of versatile silicon timing devices.  A single resistor, RSET, programs the LTC6992s internal master oscillator frequency.  The output frequency is determined__ Linear Technology/Analog Devices App Note, Oct 26th 2010

Jogging Timer -  3V Battery powered; Beeps after a fixed minutes delay __ Contact Flavio Dellepiane, fladello @ tin.it

Keep clocks in line with LVDS replicator -  01/06/00  EDN Design Ideas:  intended for use in telecommunications and other high-speed data systems, National Semiconductor's DS-92CK16 chip (Picture) allows you to generate multiple copies of clock signals with a channel-to-channel skew of 50 psec.   __ Circuit Design by Graham Prophet

Klausmobile Tube Tester -  The tester is an entirely analog device controlled by a PCI bus industrial DAC/ADC card.  As built, it enabling curve-tracing of small single and dual triodes with indirect heating.  Dual triodes can be tested each side separately or both sides in parallel.  Full tests of pentodes are possible with an external screen grid supply.  The design __ Contact klausmobile @ yahoo.Com

Knight Rider -  in the Knight Rider circuit, the 555 is wired as an oscillator.  it can be adjusted to give the desired speed for the display.  The output of the 555 is directly connected to the input of a Johnson Counter (CD 4017).  The input of the counter is called the CLOCK line.  __ 555-Timer

Knock Alarm with timer -  This is a circuit for a knock alarm that uses a piezoelectric plate to detects vibration due to knocking and activates an alarm for about ten seconds __  Electronics Projects for You

Kojak Siren -  Here is a very simple Kojak siren that is built with two 555 timer ICs  and has 2 linear potentiometers that allows the control of sound speed and tone.  IC 2 produces a sound that can be adjusted with P2 and then drives a small speaker.  The amplitude of the signal is modulated by IC 1 with a low frequency signal.  The modulation __ Designed by Popescu Marian

Landscape Sprinkler & Drip Timer Project  -  The timer circuit uses CD4000 series CMOS logic -no firmware at all.  The circuit board was cut to fit where the original circuit board in the Rain Bird Timer had been.  The barrier terminal strip was salvaged from the original circuit board (Gates and counters; no microcontroller)  __ Designed by Dick Cappels

Lap Counter for Swimming Pools -  Do you swim laps to keep in shape? This simple Picaxe-powered counter will keep track of the number of laps you've done__ SiliconChip

Got Designs?
Please eMail
if you want me to link to and/or post your original design Thanks.

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