DDS Generates Precise PWM Waveforms - 10/02/03 EDN Design Ideas: Pulse-width modulation is a simple way to modulate, or change, a square wave. in its basic form, the duty cycle of the square wave changes according to some input. The duty cycle is the ratio of high and low times in the square wave Design by Colm Slattery Analog Devices, Limerick, Ireland
DDS using AD9835 - The purpose of this project is to learn about DDS circuit. The AD9835 combines the Numerical Controlled Oscillator (NCO) , COS Look-Up Table, Frequency and Phase Modulators, and a Digital-to-Analog Converter on a single integrated circuit __ Contact maxit91 @ hotmail.com
Decimal DDS Signal Generator - Timing and oscillator circuit diagrams / circuit schematics __ Designed by zl1wtt
Delayed Pulse Generator - This circuit generates a short 10ms pulse 15 minutes after a “start” pushbutton switch is activated. . . Circuit by David A. Johnson P.E.-October, 2005
Design & Construction of Radio Frequency (RF) Oscillators - Every oscillator has at least one active device (smarties don't complicate matters for me - just read on) be it a transistor or even the old valve. This active device and, for this tutorial we'll stick to the humble transistor, acts as an amplifier. There is nothing flash about that. For this first part of the discussion we will confine ourselves to LC Oscillators and I'll keep the maths to an absolute minimum.__ Ian Purdie
D-Flip/Flop One Shot Circuit - Yes you can use cheap D flip/flop logic circuits as nice one-shot pulse generators. This schematic shows how the popular CD4013 and the CD74HC74 can be used to generate pulses ranging from nanoseconds to seconds. . . Circuit by David A. Johnson P.E.-June, 2000
Digital Audio Signal Generator, Part 1 - This Digital Audio Signal Generator has TOSLiNK and coax (S/PDiF) digital outputs, as well as two analog audio outputs. if a digital output is used, the harmonic distortion from a high quality DAC is extremely low. Alternatively, if you use the analog outputs the harmonic distortion of the sinewave signal is typically still very low at less than .06%.__ SiliconChip
Digital Audio Signal Generator, Pt.2 - Last month, we described how the S/PDiF Digital Audio Signal Generator works. This month, we describe how to assemble the PC boards, mount them in the case and check that they are working correctly.__ SiliconChip
Digital Audio Signal Generator, Pt.3 - in the March and April 2010 issues, we described the design and construction of our new Digital Audio Signal Generator. The final article this month has the driving instructions.__ SiliconChip
Digital countdown timer may never need battery replacement - 23-Jun-05 EDN Design Ideas: Processor-based timer draws microamps Design by Mark E Buccini, Texas Instruments, Houston, TX
Digital Signal Controls Sine Generator - 05/15/03 EDN Design Ideas: The circuit of Figure 1 produces an accurate, variable-frequency sine wave for use as a general-purpose reference signal. it includes an eighth-order elliptic, switched-capacitor lowpass filter, IC 3, which uses a 100-kHz square-wave clock signal that microcontroller IC 2 generates. (Any other convenient square-wave source is also acceptable Design by Simon Bramble, Maxim Integrated Products, UK
Digital Signal Processor DSP for Radio Communications - The W9GR DSP-3 is an improved low cost digital signal processor for radio communications use. it features 18 DSP functions, a LED display, and 13 bit audio precision__ Quantics
Digital signals produce pure sine waves - 10/09/97 EDN Design Ideas: Analog oscillators produce excellent sine waves but are temperamental and hard to design. They also require extensive redesign every time you change the oscillation frequency. Digital oscillators. Design by Ronald Mancini, Harris Semiconductor, Melbourne, FL
Digital waveform generator provides flexible frequency tuning for sensor measurement - 17-Dec-04 EDN Design Ideas: Variable-resistance sensors convert a fixed dc excitation voltage or current into a current or voltage that's a straightforward function of the quantity undergoing measurement. in another class of sensors, moving objects or fluids produce a sensor signal by altering an LC circuit's inductance or capacitance Design by Colm Slattery, Analog Devices, Limerick, Ireland
Distort Duty Cycle for CML Inputs - 08/05/04 EDN Design Ideas: To test a gigabit-speed data-recovery chip, you need a clock with a controllable duty cycle. Because most pattern and clock generators have a fixed duty-cycle output of 50%, the design may require a small circuit to distort the duty Design by Dieter Verhulst and Xin Yin, Ghent University, Belgium
DMA eases CPU's workload for waveform generation - 12/05/05 EDN Design Ideas: Code uses the fewest cycles to implement periodic waveform with DACs Design by Mike Mitchell, Texas Instruments, Houston, TX
Dramatically Increase the Frequency Range Of RC-Based Voltage-Controlled Oscillators - 09/21/12 EDN Design Ideas: Add a varactor to a voltage-controlled oscillator to increase the tuning range. A typical voltage-to-frequency converter—also known as a VCO (voltage-controlled oscillator) —IC has a simple linear tuning characteristic relating input voltage to output frequency. it is usually of the form F=kV/RC, where RC is the time constant of the associated timing resistor and capacitor. The output frequency range of these parts varies, but few, if any, tune over the entire range with one set of RC timing components. if you change the timing ratio as the input voltage changes, however, you can magnify the tuning range to take advantage of nearly the entire frequency range in one implementation. Design by Shawn Stafford, Pittsburgh, PA
DTMF Coder Makes Low-Cost Sine-Wave Generator - 10/13/94 EDN Design Ideas: A telephone DTMF IC produces, by design, two tones if you connect a single intersection of the IC 's 4[x]4 keypad matrix (Fig 1]. (Telephones commonly have 3×4 keypads but, unknown to many people, the applicable standard allows for a fourth row of four keys. ]But, if you connect two key inputs at once, the IC produces a single-frequency, Design by Criscuolo Anna Rita, Labtec Telecommunications, Nichelino, Italy
ELC signal between 200Mhz-400Mhz - if you need a clean emitter coupled logic (ECL) type signal between 200MHz and 400MHz this circuit works fine. it uses four voltage-controlled capacitors to change the frequency . . . Hobby Circuit designed by David Johnson P.E.-March, 1999
Electronic Canary Sound Effects - An electronic version of a chirping canary. May be used as an alarm, a sound effects generator or perhaps a replacement doorbell __ Designed by Andy Collison
Enhanced, three-phase VCO features ground-referenced outputs - 01/19/06 EDN Design Ideas: Three-phase VCOs (voltage-controlled oscillators) see service in many applications, including power inverters and in electronic-music synthesis as control and modulation sources. A previous Design idea describes a basis for a simple, three-phase VCO (Reference 1). However, adding a few components enhances the circuit's performance. Design by Harry Bissell Jr, Welding Technology Corp, Farmington Hills, MI
Few Extra Components Stabilize Oscillator - 02/15/96 EDN Design Ideas: The circuit beneath the dashed line in Figure 1 is the well-known Wien-bridge oscillator. The lamp is a common tungsten incandescent bulb. its resistance forms a substantial part of the gain-setting network. For the oscillator to function properly, the increase in lamp resistance accruing from the ac signal must bring the open-loop Design by Israel Schleicher, Green Spin Bakersfield, CA
FIFO Makes Cheap Waveform Generator - 12/21/95 EDN Design Ideas: The circuit in Figure 1 shows the basic configuration of a simple and inexpensive arbitrary waveform generator. IC 1’s 82C54 produces the time base for the wave table. This IC can generate a 152-Hz to 5-MHz clock under software co Design by Todd Williams, Napco Security Systems Amityville, NY
Flashing LED Advertising Badge #1 - I have seen numerous flashing light badges at trade shows and conventions. They are often handed out as gifts to promote some business. The devices often use inefficient circuits, which cause the battery power source to be quickly depleted . . . Hobby Circuit designed by Dave Johnson P.E.-March, 2002
FleaPower Oscillator Consumes only 1 µA - 05/21/98 Design ideas - (Multiple circuits listed, scroll to find this one) A simple way to make an oscillator is to use a resistor, a capacitor, and a Schmitt trigger (Figure 1a]. However, this circuit uses several tens of microamperes because of the voltage transitions at the Schmitt trigger's input. The CMOS
device consumes almost no power when the input is either high or low. Whenever the input voltage is at an intermediate Design by Yongping Xia, Teldata Inc, Los Angeles, CA
Flexible Outputs from Square Wave Driver - This circuit can produce an output signal ranging from DC to 100KHz. it can source a voltage ranging from 1v to 30v. it can sink a voltage ranging from zero volts to –30v. it can drive up to 200ma of current and can even be switched to a floating tristate . . . Hobby Circuit designed by David Johnson P.E.-July, 2000
Flip Flop - in this project we examine one of the most valuable circuits to be invented, the flip flop. Originally it was designed with VALVES, along with its simpler version (without the two capacitors, called a bi-stable Multivibrator) , it was realised it __ Designed by Collin Mitchell
Flip Flop Flashers Buzzers Etc - Several circuits here. The familiar astable flip-flop circuit is a handy configuration for making flashers or generating squarewaves. Here is a typical alternating LED flasher with the LEDs in the emitters instead of collectors as is normally done. The bias resistors are directly connected __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Form Positive Pulses from Negative Pulses - 07/14/11 EDN Design Ideas: Create positive pulses even when negative pulses vary in amplitude. The circuit in this Design idea converts negative pulses to positive pulses. Although that task may seem simple, the negative pulses have amplitudes of −5 to −2V. The positive pulses also need different pulse widths, depending on the application, and the negative pulses are trapezoidal. The pulses must travel over a long-distance transmission line to a control device. Several circuits solve the problem, depending on the amplitude and shape of the pulses. Design by Vladimir Rentyuk, Zaporozhye, Ukraine
Four Frequencies Generator - During development, testing and maintenance of digital and analogue electronic circuits and embedded systems, there is a need for TTL and CMOS
signals produced by stable frequency sources. These sources are...__ Electronics Projects for You
Four Transistor Tracking Transmitter - Schematic and parts list only, no circuit description included. __ Designed by Tony van Roon VA3AVR
Function Generator - Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc
Function generator - Function generator by NE566__
Function Generator - Built around a single 8038 waveform generator IC , this circuit produces sine, square or triangle waves from 20Hz to 200kHz in four switched ranges. There are both high and low level outputs which may be adjusted with the level control. This project makes a useful addition to any hobbyists workbench as well. __ Contact IQ Technologies
Function generator based on 8038PCD - Built around a single 8038 waveform generator IC , this circuit produces sine, square or triangle waves from 20Hz to 200kHz in four switched ranges. There are both high and low level outputs which may be adjusted with the level control. This project makes a useful addition to any hobbyists workbench as well __ Designed by Andy Collison
Function Generator Has Variable Frequency - 02/17/11 EDN Design Ideas: Use a function-generator IC and an internal reference voltage to provide reliable frequency settings. Design Adolfo Mondragon, Electrolux Products, Juarez, Mexico; Edited by Martin Rowe and Fran Granville - February 17, 2011
Function Generator Sine / Triangle / Square / SaW / Burst Sweep Noise based on PIC16F870 - PIC Project Sine Triangle Square Saw Burst Sweep Noise - runs on a PIC 16F870 __ Designed by Luhan Monat-Mesa Arizona |