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Audio noise generator drives earphones or small speaker - This is a circuit that generates white noise, rolled-off to drive earphones or a small speaker. White noise creates is a "rushing" sound, which sounds something like air rushing by your ear (s). White noise would be flat with frequency, and since this circuit rolls off within the audio range, I refer to it as "rolled-off" noise. White (or rolled-off) noise __ Designed by Dick Cappels Audio Noise Limiter - Audio noise can be annoying, especially if you are trying to listen to a very weak radio station. Peaks of unwanted background noise completely swamp the broadcast signal, making it unintelligible....__ Electronics Projects for You
Broadband Random Noise Generator - DN70 Design Notes__ Linear Technology/Analog Devices
Characterizing noise in high-performance voltage-reference ICs - 09/03/09 EDN Technical Article: Measuring the noise performance of a modern voltage reference requires special measurement techniques. Design by Jim Williams, EDN's most revered contributor, passed away in June 2011 after a stroke. He was 63.
Digital noise generator - When you need to test an audio circuit with broadband noise, this circuit works great. It uses just three inexpensive C-MOS ICs that generate a series of output pulses whose widths vary randomly. I included a level control pot . . . Hobby Circuit designed by David Johnson P.E.-July, 2000
DSP Technique Generates Arbitrary Noise - 10/13/94 EDN-Design Ideas A simple addressing technique can yield long bursts of pseudorandom noise without performing strenuous real-time computations or consuming large amounts of memory. The trick is first to fill memory with a short, precalculated pseudorandom sequence and then to access the samples in that sequence indirectly using a randomly generated pointer. Design by Jeff Shadely, Flight Safety International, Broken Arrow, OK 10/13/94
Electronic Chime - Scroll Down to find this circuit. This circuit simulates a chime similar to the sound many cars make when the keys are left in the ignition. The bottom two gates form a squarewave audio oscillator that drives the base of the 2N4401, turning it on and off at an audio rate. The top two gates produce a short low-going pulse about once per second that discharges the 10 uF capacitor through the diode. The voltage then jumps up and slowly decays __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Emergency Siren Simulator - This siren circuit simulates police, fire or other emergency sirens that produce an up and down wail. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Filtered noise generator using a voltage regulator source - EDN-Design Ideas - 02/24/2014 A controlled-bandwidth noise source using an unusual topology Design by Vladimir Rentyuk
Mm5437 Noise Generator - Many years ago National Semiconductor came out with a neat white noise generator IC. They are no longer being made but they can still be found on eBay. This little 8 pin part is very easy to use. It draws about 4ma of current and can operate over a range of 4.5v to 11.5v. It might even operate down to 3v. . . . Circuit by David Johnson P.E.-July, 2017
Make noise with a PIC - 7-Aug-03 EDN-Design Ideas - Building a stable noise generator for audio-frequency purposes requires only a few components. The circuit in Figure 1 relies on linear-feedback shift registers and some simple software. An eight-pin Microchip (www.microchip.com] PIC12C508 controller (IC2] with a short program generates pseudorandom noise at its output pin, GP0 Design by Peter Guettler, APS Software Engineering GmbH, Cologne, Germany
Noise enhancer adds short noise pulse - EDN-Design Ideas - 11/11/96 The circuit in Figure 1a eases noise detection by multiplying the number of pre-existing short noise pulses by two or three (Figure 1b). After the circuit multiplies these noise pulses, you can detect the noise as a decrease in the S/N ratio or as an increased pulse frequency. Design by Shyam Sunder Tiwari, Fiber Optics and Digital Imaging, Kalpakkam, India
Noise Enhancer Adds Short Noise Pulse - EDN-Design Ideas - 11/11/96 The circuit in Figure 1a eases noise detection by multiplying the number of pre-existing short noise pulses by two or three (Figure 1b). After the circuit multiplies these noise pulses, you can detect the noise as a decrease in the S/N ratio or as an increased pulse frequency. Design by Shyam Sunder Tiwari, Fiber Optics and Digital Imaging, Kalpakkam, India
Noise_Generator_using_Mm5437 - Many years ago National Semiconductor came out with a neat white noise generator IC. They are no longer being made but they can still be found on eBay. This little 8 pin part is very easy to use. It draws about 4ma of current and can operate over a range of 4.5v to 11.5v. It might even operate down to 3v. . . . Hobby Circuit by David Johnson P.E.-July, 2017
Noise Meter - Normally, sound intensity up to 30 dB is pleasant. Above 80 dB, it becomes annoying. And if it goes beyond 100 dB, it may affect your psychomotor performance, detracting your attention...__ Electronics Projects for You
One IC forms pseudorandom noise source - 03/21/02 EDN-Design Ideas - Trying to find a single IC noise source can be frustrating. National Semiconductor once made such a noise source for audio applications, but it's now hard to find. This situation leaves the designer with several choices, most of which involve using several ICs. You can take the analog approach of using a lot of gain to amplify diode-avalanche noise, or you can design a linear-feedback-shi Design by Steve Ploss, Veridian, Dayton, OH
Pink Noise Generator (Flicker Noise) - The circuit shown in fig.1 is an implementation of a flicker noise generator described in NBS technical note #604, "Efficient Numerical and Analog Modeling of Flicker Noise Processes" by J. A. Barnes and Stephen Jarvis, Jr. With the values shown the circuit will give a 1/f noise slope from below one hertz to over four kilohertz. The circuit employs a TLC2272 op-amp although other high impedance, low noise op-amps will work. The amplifier must have low noise current since a farily high value resistor is used to generate the 50 nV white noise; choose an op-amp with noise voltage less than 15 nV/root-Hz and noise current less than 0.1pA/root-Hz, both easily obtained with several modern op-amps. The capacitor values vary slightly from the calculated values in the referenced paper to simplify construction and the circuit includes bias to allow the use of polarized electrolytic capacitors. The electrolytic capacitors should be selected carefully since many aluminum electrolytics have poor tolerances. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Pink Noise Generator for Audio Testing - For loudspeaker and room acoustics testing ( __ Designed by Rod Elliott ESP
Police Car Siren - This siren circuit simulates police, fire or other emergency sirens that produce an up and down wail. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Pseudonoise Generator Doubles Its Speed - 12/22/94 EDN-Design Ideas - You can double the speed of a standard pseudonoise (PN) generator by using additional exclusive-OR gates and a fast 2:1 multiplexer. A PN generator built with an n-stage feedback shift register gives a maximal-length sequence of 2N-1 bits. The upper limit of the PN-generator clock depends on the device logic family. For example, a PN generator built with 74LS74 flip-flops and a 74LS86 exclusive-OR gate has a top speed of 16 to 18 MHz. Design by R N Mutagi, Space Applications Centre, Ahmedabad, India
Single IC forms pseudorandom noise source - 03/21/02 EDN-Design Ideas - Trying to find a single IC noise source can be frustrating. National Semiconductor once made such a noise source for audio applications, but it's now hard to find. This situation leaves the designer with several choices, most of w Design by Steve Ploss, Veridian, Dayton, OH
Siren Simulator - This siren circuit simulates police, fire or other emergency sirens that produce an up and down wail. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
Versatile noise generator tests signal recovery gear - 05/19/14 EDN-Design Ideas - Accurate noise generator allows mixing-in of a clean test signal. I sometimes need a noise generator for testing equipment, and useful signals must often be mixed with the noise, such as when testing equipment designed to extract a clean signal from a contaminated one. This Design Idea implements such a piece of test equipment. Design by Vladimir Rentyuk
White & Pink (1/F) Noise Source - The circuit shown in fig.1 is an implementation of a flicker noise generator described in NBS technical note #604, "Efficient Numerical and Analog Modeling of Flicker Noise Processes" by J. A. Barnes and Stephen Jarvis, Jr. With the values shown the circuit will give a 1/f noise slope from below one hertz to over four kilohertz. The circuit employs a TLC2272 op-amp although other high impedance, low noise op-amps will work. The amplifier must have low noise current since a farily high value resistor is used to generate the 50 nV white noise; choose an op-amp with noise voltage less than 15 nV/root-Hz and noise current less than 0.1pA/root-Hz, both easily obtained with several modern op-amps. The capacitor values vary slightly from the calculated values in the referenced paper to simplify construction and the circuit includes bias to allow the use of polarized electrolytic capacitors. The electrolytic capacitors should be selected carefully since many aluminum electrolytics have poor tolerances. __ Contact: Charles Wenzel of Wenzel Associates, Inc.
White noise source flat from 1Hz to 100kHz - 09/12/13 EDN-Design Ideas - Making a flat noise source is all about finding "le diode juste" - White noise is very useful in testing many types of circuits. When combined with an FFT analyzer, a flat noise source can make for quick and easy gain plots of circuits. If the noise into a circuit is flat and of known quantity, then the gain of the output circuit is easy to determine, even visually. This method has been used at least as far back as 1978 on the HP3582A Low Frequency Spectrum Analyzer [1]. Design by Steve Hageman
White-noise generator has no flicker-noise component - 03/20/08 EDN-Design Ideas - A white-noise generator with no flicker noise proves useful for testing circuits with an extended low frequency response Design by Alfredo Saab and Randall White, Maxim Integrated Products, Sunnyvale, CA |
