Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com, has 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.
We make every effort to link to original material posted by the designer. 
Please let us if you would like us to link to or post your design.

HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches

Digital  / Logic Circuits 
Digital Circuits:   #'s - C       D - G       H - M       N - R       S - T       U - Z

Last Updated on: Monday, December 25, 2017 01:50 PM

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

2 DDS ICs implement Amplitude shift keying -  12/25/03 EDN-Design Ideas Many communications systems, including RFID systems and cable modems, use AM   (amplitude modulation].  This design idea shows how two DDS   (direct-digital-synthesis] devices can implement AM and ASK   (amplitude-shift keying] over a range of frequencies.  The AD9834 complete 50-MHz DDS IC   (Figure 1) has a current output, so you can easily sum the outputs of two orof them by connecting them to a __ Circuit Design by Noel McNamara, Analog Devices, Limerick, Ireland

2 gates & a microprocessor form digital PLL -  04/14/05 EDN-Design Ideas Low-frequency PLL needs just a processor and gates __ Circuit Design by Kenneth Martin, TareTronics Inc, Corinth, MS

2 Gates Expand ASIC's Memory Decoding Range -  03/29/01 EDN-Design Ideas Many electronic circuits implement chip-select lines on an ASIC.  From  beginning of  design cycle,  chip selects, CS0 to CS4, have defined bases on  memory map   (Figure 1) .  Adding functions __ Circuit Design by Vinh Hoang, Ericsson Inc, Brea, CA

2 transistors form bidirectional level translator -  11/07/96 EDN-Design Ideas This example illustrates a translation from 5 to 3V, but it can accommodate almost any other voltage levels, provided the logic-low levels are equal   (usually0V].  Translations from 1 to 100V are possible, albeit rather slow.  The key to this circuit is the unusual cross-coupling of the emitters __ Circuit Design by Jim Hagerman, Nokia Mobile Phones, San Diego, CA

2 Way IR Terminal -  This unit provide 2 way IR communications using a numeric keypad and an LCD display.  Data is sent and recieved in ASCII with no regard to what the data means to any particular device __ Designed by Luhan MonatMesa Arizona

2.2-100V Zener Diode Tester -  Got a bunch of unknown diodes and zener diodes? Check 'em all with this __ SiliconChip

2.4GHz Audio/Video Link -  Maximum legal power easy to build fantastic range cheap ...__ SiliconChip

2.4GHz Wireless A-V Link -  We've published a few audio/video transmitters/receivers over the years but none were as compact as this 2.4GHz model.  Whether you want it for legitimate security/monitoring applications or simply for fun, it's easy to build and a lot cheaper than buying a ready-made system!__ SiliconChip

2.5 GHz Frequency counter -  This project describes a very powerful frequency counter.  Very simple construction which everyone can build.6 LED display will present the frequency with 1kHz resolution and RS232 communication to computer is available as option.  The software has also been implemented with some smart functions, for calculating frequencies in receivers where IF is 455kHz or 10.7MHz.  I present schematic, PCB, components and window software.  

2^16 remote control encoder & Decoder -  Control up to 16 remote digital output lines by this remote control encoder/decoder.  The encoder can transmit either using a radio module or an infrared LED.  The decoder outputs can be latched or momentary __ Designed by Peter Jakab

240V Mains Filter for Hifi Systems -  Get rid of clicks, pops, spruigles and sundry other noises in your hifi system.__ SiliconChip

2-chips simplify layout for high-end embedded control -  04/01/99 EDN-Design Ideas NOTE :  File contains many designs.   Scroll to this one.   If you are considering using one of the 32- or 64-bit RISC Ps from Integrated Device Technology   (IDT], the companys new RC32134 and RC64145 system-controller ICs   (Picture] can make your job easier.  The chips provide synchronous-DRAM, memory, and I/O control; a PCI interface; and peripherals, including UARTs, timers, and interrupt controllers.  The 32134 for the RC32364 P provIdeas a glueless interface to DRAM Page includes several designs.   __ Circuit Design by Graham Prophet

2-Digit Counter -  This article describes a 2-Digit Counter using a Microchip PIC12F629.  It shows what can be done with an 8-pin chip having just 5 output lines and one input line.  The chip drives two7-segment displays and this would normally require 7 lines to drive the segments plus another one or two lines to select the displays __ Designed by Collin Mitchell

2-IC combines digital & analog signals to make multiplier -  EDN-Design Ideas 01/29/2013    Combining a PWM signal with an analog signal and low-passing the result effectively multiplies the analog signal by a digital value __ Circuit Design by Rick Mally, Independent Designs LLC, Denver

2-Phase, Spread Spectrum, DDR Memory Supplies with Ceramic Output Capacitors -  The LTC3776 is a 2-phase dual output synchronous stepdown switching regulator controller for DDR/QDR memory termination applications.  The second controller regulates its output voltage to 1/2 VREF while providing symmetrical source and sink output current capability.  __ Linear Technology/Analog Devices App Note, Jun 29th 2011

3 Digits Digital Volt Meter with PIC16F676 -  This is simple 3-digits digital volt meter.  PIC16F676 used to read analog signal    (voltage) and display the value on 3-digits 7-segment.  You can apply similar principles to measure DC current with parallel R shunt.  

32 Bit Serial Receiver -  This is the schematic for an FM transmitter    (57.6 K Baud TTL & CMOS ) with 3 to 3.5 W output power that can be used between 90 and 110 MHz.  Although the stability isn't so bad, a PLL can be used on this circuit.   __ Designed by Bill Bowden

32.768 kHz Oscillator using a Common Watch Crystal -  Below are a couple circuits you can use to produce a 32.768 KHz square wave from a common watch crystal.  The output can be fed to a 15 stage binary counter to obtain a 1 second square wave.  The circuit on the left using the 4069 inverter is recommended over the transistor circuit and produces a better waveform.  The single transistor circuit __ Designed by Bill Bowden

4 Ch Digital Logic Analyzer & 5 Ch Digital Oscilloscope in Parallel Port -  This is one of the simplest circuit for a PC parallel port based DLA.  The circuit is mainly used to protect the port which is fabricated on the otherboard itself.  The IC 74LS04 is an inverter and acts as a buffer.  The Zener is used for undervoltage and overvoltage protection.  If a voltage > 5V appears on the input, The buffer will not transmit this voltage to the PC.   __ Designed by Huzaifa S. Sidhpurwala, India

4 Digit Crystal-Controlled Timing Module -  Just change the chip to build a stopwatch , a photographic timer, a frequency meter or a programmable down timer.__ SiliconChip

4 Way Spinner -  A 4 light bulb spinner that slows and stops on a random bulb.  PCB included in pdf __ Contact: P. Townshend EduTek Ltd

433MHz UHF Remote Switch -  Ideal for remote control of practically anything you like and with a range of more than 200m, this wireless transmitter and receiver pair use pre-built UHF modules that make it easy to construct and use.__ SiliconChip

4-Digit Alarm Control KeypA - D -  Alarm Control Keypads:  This Keypad is suitable for the Modular Burglar Alarm.  However, it has other applications.  Pressing a single key will energize the relay.  Entering the Four-Digit code of your choice will de-energize it.  __ Designed by Ron J.

4-Digit Keypad Controlled Switch -  Universal Keypad-Controlled Switches:  This is a Universal version of the Four-Digit Alarm Control Keypad.  I have modified the design to free up the relay contacts.  This allows the circuit to operate as a general-purpose switch.  I've used a SPCO/SPDT relaybut you can use a multi-pole relay if you wish.  __ Designed by Ron J.

4-Input mini Logic Analyzer -  A mini Logic Analyzer wich has 4 inputs, it's portable    (55x65 mm) , battery powered and can capture data up to 400kHz. __ Designed by Vassilis Serasidis

4-Way Event/Race Anything Timer -  It's based on a PIC microcontroller and can time up to four seperate events.  You can even get infrared sensors to start and stop the timin__ SiliconChip

5 Hints for Debugging MicroController-based Designs an 1458 -  Application Note__ Aligent

50 MHz Frequency Counter -  This project is nice and small frequency counter that reads frequency from 1 Hz to 50 MHz that I have modified from original designed by Weeder Technologies.  I have designed new PCB to fit with 16X1 LCD and change source code for compatible with new small PCB Specifications, Auto-ranging with floating decimal point.  , Up to 7 digits displayed on 1X16 LCD.  , Auto-adjusting gate speed    (0.1sec to 1 sec) .  , Microcontroller-based circuitry provides for simplicity, ease of assembly, and highly stable readout.  , Sensitivity approximately 100 mV RMS    (100 Hz to 2 MHz) , 800 mV RMSAT50 MHz.  , Input overload protected.  

50 MHz Frequency Counter Voltage Meter & SwR/PWR Indicator -  This is a successor of the PIC16C71 4-digit LED f-counter & V-meter.  Some hard to find parts used in the previous version, which are out of production for some time, has been omitted.  A rather early PIC16C71 has also been replaced by 28-pin device PIC16F876 __ Designed by Aleksander Stare

5V logic pulser is battery-powered -  09/16/99 EDN-Design Ideas A battery-powered, pushbutton-triggered TTL/CMOS -compatible source of debounced 5V logic pulses is a simple but handy piece of test equipment to have in any tool kit   (Figure 1) .  The circuit's battery-powered operation complicates what would orwise be a trivial exercise in switch-bounce and timing-Circuit design.  The convenient use of battery power __ Circuit Design by W Stephen Woodward, University of North Carolina, Chapel Hill, NC

60 minute PIC Count Down Timer -  On this page, I will introduce the Count-down timer with PIC16F84A.  I am putting a count-down timer by the hardware on Electronic Circuits Application Garage.  The function of the timer is the same as it approximately.     (The stop switch is added) Because this unit was made compactly, the wiring of the back becomes quite complicated 

6090 Digital Decoder Schematics -  Several designs on this page __ Designed by John Simonton

68HC11 Function Generator This site contains complete schematics and code for a 68HC11 based frequency counter, square wave synthesizer, sine wave synthesizer, programmable filter, capacitance and inductance meter, with a digitalker speech synthesizer output.  Project specifications are given below __ Designed by Michael Ellis

68HC11 Instruction Halts External RC Clock -  04/27/95 EDN-Design Ideas Using the circuit in Fig 1, a 68HC11 P's stop instruction can put the P's external RC-oscillator clock, as well as the P itself, into a low-power mode.  On receiving an interrupt, the P will exit the stop condition and enable the RC clock.  The RC clock, being a low-Q circuit, will start up immediately.  Crystal oscillators, on the other hand, can waste precious milliseconds coming up to speed and stabilizing __ Circuit Design by Allen Harstine, Micro Systems Engineering Inc, Lake Oswego, OR

68HC11 Read Encoder -  The encoder is connected to PORTA PA0 and PA1 --  The board must be in BOOTSTRAB MODE    (tested with Loggyboard)  __ Designed by Ludwig Orgler-Fachingenieur Elektrotechnik

68HC11 stepper Motor control -  Simple circuit with 16-pin Nitron chip 68HC908, easy analog setting, source code with ICC08.  New s-record for 8-pin 68HC908QT2! __ Designed by Ludwig Orgler-Fachingenieur Elektrotechnik

68HC11 Synthesizes Accurate Sine Wave -  09/02/96 EDN-Design Ideas You can use a 68HC11 and a 12-bit serial DAC   (Figure 1) to generate accurate sine waves without using floating-point arithmetic.  Figure 2 shows a block diagram for this sine-wave generator.  You can easily analyze the generator's behavior by writing state equations in the z domain.  You can also write equations in the s domain.  The location of the two poles __ Circuit Design by Mika Maaspuro, Espoo, Finland

68ksingle Board Computer -  Build a 32-bit power single board computer.  The board fetures 68HC000AT8MHz, 256kB FLASH, 256kB SRAM.  Available now schematic of DTACK and decoder that use CPLD.   __ Designed by Wichit Sirichote

6-Decade Resistance Substitution Box -  Get a million resistance values with this __ SiliconChip

6-Digit Frequency Counter Module -  Low-cost unit measures frequencies up to 40MHz__ SiliconChip

7 Segment Display & KeypA - D -  Since the output buffer ofP1 can sink 20mA    (each output pin, but maximum IOL for all outputs was limited at 80mA) , thus we can use P1 to drive LED display directly.  As shown in the circuit, Two common-anode 7-segment LEDs are connected to P1 with 180 Ohms current limiting resistor.  Each segment of two LED __ Designed by Wichit Sirichote

8 Hints for Debugging Siemens MCU-based Designs -  Application Note__ Aligent

8 pin C forms one-chip Programmable VCO -  09/24/98 EDN-Design Ideas NOTE :  multiple circuits, scoll to this one.  The circuit in Figure 1 uses a Microchip 8-pin C   (PIC12C671]as a voltage-controlled oscillator   (VCO].  Because  PIC12C671 has an internal 4-MHz oscillator, four-channel 8-bit A/D converters, and built-in power-reset circuitry, you need no external components to configure  VCO.  The C reads two analog inputs through AN0 and AN1 __ Circuit Design by Yongping Xia, Teldata Inc, Los Angeles, CA

80188XL Engine Tachometer / Race Computer -  The objective of this project is to design a high speed digital engine tachometer.  This requires the design and development of a hardware and software solution to monitor the status of an engine in real time.  In addition, information relating to the overall health and systems of the vehicle can be displayed.   __ Designed by Stephen Manley-smanley @ nyx.net

8051 Development System Board -  This is the complete schematic for the development board.  Address and Data bus wires are drawn separately    (not in a bus) , so that it's easy to color over them on a printout, if you choose to manually connect the wires.  It really is easier to buy a bare circuit board, though. __ Designed by Paul Stoffregen

8051 Microcontroller Overview & Hardware Tutorial #1 -  The intel 8051 series 8bit microcontroller, originally introduced in 1980, remains popular and has had perhaps the longest product life of all such devices.  It has become the industry standard for real-time and Boolean control applications.  While some  (who should know better) have said that the 8051 is dead, it continues to be a viable

8051SBC V1.0 (Single Board Computer) -  I decided to rename C52EVBto be 8051SBC.  Since the cpu can be any 8051 compatible chips with 40-pinDIP package.  The old day chips, say 8031, 8751, 8032 or the new chips, 89C51, 89C52, 89C51RD2 can be used without any problem.  Some may thinkthat your old chips were useless, now you can use it for many projects.  The monitor program of new 8051SBC was placed at external 32kB EPROM __ Designed by Wichit Sirichote

8088 Maximum Mode SB - C -  As an integral part of an advanced computer science course in microcomputer systems it was thought that students could benefit from the design of a single board computer system based on a readily available microprocessor.  This led to the project that is described in this paper.  Most of the actual design work was done by James Antonakos as part of an Independent Study project.  The result was a single board microcomputer system    (SBMCS) that requires only a power supply and a serial monitor to be fully functional.  This same project will be assigned to advanced undergraduate and intermediate graduate computer science students working in teams.  A photograph of the working single board microcomputer system that was designed and constructed is given in Figure 1.   __ Designed by Richard R. Eckert and James L. Antonakos

89c2051proto Board -  This single sided proto board provides an economical solution for developing and testing the projects around Atmel 20 pin series u-controllers    (89Cx051 & AVR) .   __ Designed by Wichit Sirichote

89s52 Project Board -  Simple 89S52 board for student projects __ Designed by Wichit Sirichote

8-Bit Microcontroller Implements Digital Lowpass Filter -  01/24/08  EDN-Design Ideas A simple assembler routine fits a digital lowpass filter into a microcontroller __ Circuit Design by Abel Raynus, Armatron International, Malden, MA

8-Digit Code Lock for Appliance Switching -  This code lock is useful for appliances requiring exclusive or authorised use by those who know the preset code.  If desired, the code can be changed. The circuit doesnt require additional AND...__ Electronics Projects for You

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

9 Second Digital Readout Countdown Timer -  This circuit provides a visual 9 second delay using a 7 segment digital readout LED.  When the switch is closed, the CD4010 up/down counter is preset to 9 and the 555 timer is disabled with the output held high.  When the switch is opened,  __ Designed by Bill Bowden

      <<<         >>> 

Digital or Logic Circuits:  #'s - C       D - G       H - M       N - R       S - T       U - Z

HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches

 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |    Privacy Policy

Copyright  January, 1998 - December, 2017     David A. Johnson & Associates.  All Rights reserved. 

 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.