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Ultra Lower Power Oscillator - This circuit works much like the classic 555 timer, but draws only about 1.5 microamps from a 3 volt battery. it is highly stable under varying temperature and supply voltages. . . Circuit by David Johnson P.E.-May, 2000
Ultra Pure 125kHz Sine Wave Signal Source - For some RFID systems operating at 125KHz, a very low distortion signal source reference is needed. The circuit shown on this page produces a 10-volt peak-to-peak signal into a 50-ohm load, with a distortion of only 0.01%. . . Circuit by Dave Johnson P.E.-February, 2002
Use a Low-Cost PWM Ramp Generator In Switch-Mode Power Supplies - 04/08/10 EDN Design Ideas: include this circuit in a switching-power-supply design. Design by Dwayne Reid, Edmonton, AB, Canada
Use a PC to record four-channel waveforms - 05/25/00 EDN Design Ideas: This design idea is a sequel to a previous one, "Use a printer port to record digital waveforms, " EDN , June 18, 1998, pg 136. Both ideas are similar: Use the PC's printer port to sample waveforms, and use the PC's memory to stor Design by Dean Chen, Dycam Inc, Chatsworth, CA
Use an Op Amp as a Set/Reset Flip-Flop - 05/24/12 EDN Design Ideas: Eliminate a flip-flop package by using a spare op amp for an SR latch function. You can make a set/reset flip-flop from two NAND or NOR gates or use readily available set/reset flip-flop IC s, such as the 74HC279 quad-set/reset latch. The drawback of these methods is that they require a large amount of space to form the flip-flop. Even if you need only one flip-flop, you must use a large IC package with this approach. However, you can use a spare rail-to-rail op amp to perform the needed latch function (Figure 1). Design by Aruna Rubasinghe
Variable Frequency PWM - Schematic only, no circuits description. __ Designed by Tony van Roon VA3AVR
Variable Gain Control Produces Pure Sine Wave - 10/27/94 EDN Design Ideas: The circuit in Fig 1 delivers a pure, buffered, and level-controlled sine wave. With no tuning requirements, the circuit works with all crystals up to about 30 MHz. Design by Barry Harvey, Elantec Corp, Milpitas, CA
VCO covers 300MHz to 500MHz based on Maxim MAX2608 VCO - The datasheet says this VCO covers 300 to 500 Mhz, in this test setup with one coil it covers 350 to 475 Mhz with the controlling voltage. The output should be about -10dBm, but it's -20dBm. The stability and sideband noice was not good enough for my HAM radio project, sorry. But i'm sure it will be perfect to be used with a PLL. __ Designed by Thomas Scherrer OZ2CPU
VCO from CMOS
Schmitt Trigger IC - By changing the supply voltage fed to a classic 4584 Schmitt trigger type oscillator, the oscillator frequency can be changed over a range of 50:1. A 74HCU04 inverter is used at the output of the 4584 to maintain a constant TTL logic level signal . . . Hobby Circuit designed by David Johnson P.E.-March, 2002
Version 4 of a Ultra Low Current Oscillator - The circuit below was inspired by a programmable unjunction transistor (PUJT) circuit sent to me by Karl Isbrecht. in Karl’s circuit, the unijunction circuit made click sounds in a speaker and consumed very little power. His circuit reminded me that a PU . . . Hobby Circuit designed by Dave Johnson P.E.-January, 2010
Very Low Power Gated Crystal Oscillator - The circuit gates the output of a continuously operating 32KHz crystal oscillator to the input of a C-MOS buffer when clock pulses are needed. The technique gets around the problem of a slow starting crystal oscillator by keeping the oscillator going and switching on a transistor power stage only as needed. . . Circuit by David A. Johnson P.E.-June, 2000
Very Low Voltage Oscillator Circuit - OK, you may not ever need an oscillator to function using a power supply voltage below one volt, but if you ever do need one, here is one way to do it. Getting any electronic circuit to operate below one volt is a real challenge. Typical silicon bipolar . . . Hobby Circuit designed by Dave Johnson P.E.-October, 2008
Voltage Controls Sine-Wave Frequency - 08/17/95 EDN Design Ideas: The circuit in Fig 1 generates a 50-Hz to 1-kHz sinusoidal waveform that exhibits lower than 60-dB THD. The input voltage controls the output frequency with the relationship 1 kHz/V. The output amplitude is invariant with frequency over the entire operating range. IC 1 is a V/F converter Design by Yongping Xia, EBT Inc, Torrance, CA
Waveform Conversion - sine to square and square to sine __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Waveform Generator Demodulates FM Signals - 10/10/96 EDN Design Ideas: The circuit in Figure 1 uses the phase-detector signals of a precision waveform-generator IC to perform FM demodulation. in a standard application, the IC 's phase-detector input and output synchronize the chip's output frequency to that of an applied signal. if the signal is FM, you can extract the demodulated signal from the phase-detector output. The waveform generator Design by Doug Vargha, Maxim Integrated Products, Sunnyvale, CA
Waveform Generator Minimizes Amplitude Dependency - EDN Design Ideas: May 26, 2011 improve a waveform generator's immunity to changes in power-supply voltage. Design by Marián Štofka, Slovak University of Technology, Bratislava, Slovakia
Waveform Generator provides Flexible Frequency tuning for Sensor Measurement - 12/17/04 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 p Design by Colm Slattery Analog Devices, Limerick, Ireland
Waveform Monitor with LCD - The result was a project that includes a waveform capture circuit, a graphic LCD (Liquid Crystal Display) and a control panel with LED indicators. The details of the Graphic LCD display unit, composed of the LCD module, a serial interface, and bias supply were published earlier on this site, __ Designed by Dick Cappels
Waveform Synthesiser - Sampling, Who needs it, when you can create any arbitrary repetitive waveform you like and save it by cutting out a piece of cardboard and moving the faders up to it next time you want that waveshape. Contains a novel (?) analogue linear interpolator to create straight lines between the adjacent voltage levels, rather than the more usual staircase waveform. __ Designed by Henry
Wien Bridge Oscillator - The OpAmp Wien-bridge oscillator provides a nice view into classic oscillator design using feedback analysis. Feedback analysis reveals if your circuit is stable (well behaved) or unstable (spice design) __ Designed by Andrew R. Morris
Wien Bridge Oscillator keeps THD BeLow One PPM - 11/10/94 EDN Design Ideas: The Wien-bridge sine-wave oscillator uses a light bulb to stabilize its amplitude. The circuit doesn't have a light bulb; it sports several enhancements that lower its distortion Design by Jeff Smith, Analog Devices, Wilmington, MA
Wien Bridge Oscillator Rail-to-Rail Sine Wave Generator - Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc
Wien Bridge Oscillator with SPICE simulation - Timing and oscillator circuit diagrams / circuit schematics__
Wien Bridge Oscillator-42003.0 - Circuit ideas for Designers App Note__ Advanced Linear Devices, Inc
Wien-Bridge oscillator has simplified frequency control - in this article, a modified version of the classical circuit that uses a single low-cost variable resistor for frequency control will be described. __ Designed by Ramon Vargas 20-8-04
Wien-bridge oscillator is reborn - 06/13/02 EDN Design Ideas: in 1940, William Hewlett and David Packard launched a product from a garage. The product was a Wien-bridge oscillator. it consisted of a single-pole highpass filter in series with a single-pole lowpass filter. To keep the gain cons Design by Michael Fisch, Agere Systems, Longmont, CO
Wien-bridge Theremin - This circuit is a basic theremin with only a pitch control. it uses the "heterodyne" technique, as did Theremin's original instrument. Heterodyning is advantageous in its simplicity, and is made further attractive in this design by eliminating the coils that are usually hard to find (electronic design 10/05) __ Designed by Arthur Harrison
WIFI CAN Antenna - Got no dough for a commercial WiFI antenna? Looking for an inexpensive way to increase the range of your wireless network? A tin can waveguide antenna, or Cantenna, may be just the ticket. This design can be built for under $5 U. S. and reuses a food, juice, or other tin can __
Yield Frequency Locked Triangle Waves - 02/02/98 EDN Design Ideas: The circuit in Figures 1 and 2 generates frequency-locked triangle waves of constant amplitude. it uses readily available TTL and other older-technology parts. The circuit portion in Figure 1 comprises the frequency dividers, counters, and converter. The portion in Figure 2 contains current sources, output circuits, Design by Daniel Dufresne, Decatron, St Bruno, PQ, Canada |
