Solenoid trip works at battery's end of life - 8-Jul-04 EDN Design Ideas: This design idea involves a low-power motion-detector circuit that operates from battery power for extended times. Part of the design includes a solenoid-operated trip mechanism that triggers whenever it detects motion. The drive circuit for the solenoid in the original design worked fine as long as the battery was fresh but failed as the battery got into the middle of its life, even though suf Design by Brad Peeters, Theta Engineering, Costa Mesa, CA
Solid State Signal Lamp - This solidstate signal lamp is a good alternative to revolving mechanical signaling lamps used in ambulances. it uses ultra-bright blue LEDs for signaling. However, you can replace blue LEDs with bright...__ Electronics Projects for You
Solid-State Relay Saves Battery's Life - 09/01/94 EDN Design Ideas: The circuit in Fig 1 uses a low-resistance p-channel FET, Q4, to disconnect a load from the battery when the battery's voltage drops below a certain value. After you disconnect the circuit, it remains off until you remove and replace the battery Design by Tom Gay, Siemens, Regensburg, Germany
Solid-state relays simplify Monitoring electric car battery-voltage - 02/19/04 EDN Design Ideas: Figure 1 shows the propulsion system of an electric vehicle. it includes an electric motor, drive electronics, a mechanical transmission, vehicle control/power management, a charging system, and a battery. The long-term performance Design by Robert Krause, Fairchild Semiconductor, San Jose, CA
Some Simple Circuit test equipment to build - amateur radio construction projects. __ Designed by Peter Parker
Some test equipment to build - amateur radio construction projects. __ Designed by Peter Parker
Sonar Water-Level Meter - Three-fourths of the earth is water, out of which 97 per cent is saline (in oceans, seas and groundwater). The remaining 2.5 per cent to 2.75 per cent is fresh water, ...__ Electronics Projects for You
Sound Card Interface for PC Test Instruments - You can have a virtual electronics lab in your PC. Just attatch this simple interface to your sound card.__ SiliconChip
Sound Level Meter - One chip replacement for the standard analog meters, based on LM3915 audio level IC . __ Designed by Aaron Cake
Sound Level Meter - This sound level meter circuit can be used to control the intensity of a sound recording or in a disco. it has 5 measurement domains between 70 and 120 dB; reading accuracy is 0.5 dB. Microphone M1 is used to receive the acoustic signal and is coupled to C1, C2, R1 and R2. This components, together with the microphone’s __ Designed by Popescu Marian
Sound Pressure Level Meter - This SPL meter will allow for a broad range of Sound intensitity Tests. The 4 Transistors near the middle of the schematic, Basically make an integrated Circuit, Op-Amp. I Specifically built it this way, as it really isn't much bigger an IC and these are very common transistors. __ Designed by G.L. Chemelec
Soundmeter - A simple soundmeter using the PIC 16F628 or 16F84 __ Designed by Jose Pino
Spark Detector Uses Proximity - 27-Nov-08 EDN Design Ideas: Use a Hall-effect sensor to measure engine rpm with a voltmeter Design by Robert Most, Ferris State University, Big Rapids, MI
SPDIF Monitor - The SPDiF monitor is one of the many applications possible with the digital audio interface receiver Type CS8412 from Crystal. Other applications described in earlier issues of this magazine dealt with the decoding of the S/PDiF (Sony/Philips Digital interface Format) into data, bit clock and L/R clock in a digital voltmeter __ Designed by Popescu Marian
Specialized test judges DMT-amplifier performance - 11/20/97 EDN Design Ideas: Raditional analog test techniques and specifications, which are based on sine-wave testing, don't reflect the true performance of devices that process the discrete-multitone waveform. A unique specification--the multitone power ratio--is a better performance indicator for this application. __ Circuit Design by Richard Roberts, Harris Semiconductor
Spectrum analyser provides faster measurement - 04/01/99 EDN Design Ideas: NOTE: File contains many designs. Scroll to this one. Hewlett-Packard’s ESA-E spectrum analysers (Picture] let you perform measurements in less time and access a range of software routines to aid common measurement tasks. Five models cover 1.5 to 26.5 GHz; they have 5-msec full-span RF sweep times and can repeat measurements as fast as 28 times/sec. Span accuracy from the synthesized source is ±1%, and amplitude accuracy is ±1 dB. Ultimate Page includes several designs. Design by Graham Prophet
Spectrum Analyzer & Equalizer Designs - for audio frequencies, article first appeared in the February1982 issue of Recording-engineer/producer magazine __ Designed by Ethan Winer
Spectrum analyzer Mk 1 - A spectrum analyser is a very useful piece of test equipment to have on your workbench, yet the price tag of commercially avialable analysers places them way outside most hobbyist budgets, even when 2nd hand. All is not lost - here's a spectrum analyser design you can build yourself that won't break the bank. The pages linked above describe the construction in detail. Most photograph insets can be clicked to view a larger high resolution image. __ Designed by Hans Summers
Spectrum analyzer Mk 2 - After enjoying the Simple man's Spectrum Analyser so much, here's some real insanity. The Mk2 spectrum analyser is an attempt to resolve some of the shortcomings of the original simple analyser, improve performance, and add hosts of features. The display uses an ex-TV tube, with digital storage. Purely for the fun of it, the digital circuits are built using discrete logic rather than a microprocessor. __ Designed by Hans Summers
Spectrum Analyzer on the Oscilloscope - Schematic only __ Designed by va3iul
Spectrum Analyzer using TV-Tuner-W6WTU - Schematic only __ Designed by va3iul
Speed Alarm for Cars; Pt 1 - is your license looking a bit a bit dodgey? This compact speed alarm will help you stick to the speed limits.__ SiliconChip
Speed Checker for Highways - While driving on highways, motorists should not exceed the maximum speed limit permitted for their vehicle. However, accidents keep occurring due to speed violations since the drivers tend to ignore their...__ Electronics Projects for You
Speed Control Of DC Motor using Pulse-Width Modulation - Pulse-width modulation (PWM) or duty-cycle variation methods are commonly used in speed control of DC motors. The duty cycle is defined as the percentage of digital ‘high’ to digital ‘low’ plus...__ Electronics Projects for You
Speed Controller for DC Motor - Here is a simple circuit to control the speed of a DC motor. it can be configured to control the sweep rate of automobiles’ windscreen wiper. The circuit comprises a timer NE555...__ Electronics Projects for You
Speed Controller for Film Projectors - Do you have old family movies on film? Have you watched them lately? You may be shocked by how much they have deteriorated over the years. They need to be transferred to DVD before the film deteriorates to the point where it is unwatchable. Video conversion is not as straightforward as you might think but this simple project enables you to do it.__ SiliconChip
Speed Controller for Small Cooling Fans - Small cooling fans are used in some equipment for cooling semiconductor devices. The circuit given here is of a simple automatic speed controller for a 12V, 0.6W (or 1.2W) cooling fan...__ Electronics Projects for You
Speed IM testing - Application Note__ MiniCircuits.com
Speed Limit Alarm - Wireless portable unit; Adaptable with most internal combustion engine vehicles __ Contact Flavio Dellepiane, fladello @ tin.it
Speedometer For Model Cars - Avid model car fans are naturally enough always interested in the technology and performance of their cars. They would like to know as exactly as possible how fast their model cars actually go, for example so that they can select the final gear ratio for the best performance. Other factors can also be of interest, __
Spice 3 Models Pressure Sensors - 01/01/98 EDN Design Ideas: Commercially available versions of Spice 3, such as isSpice4 (intusoft, San Pedro, CA) , can simulate mixed-domain systems containing electrical, mechanical, physical, and mathematical elements using behavioral models. You can use these features to simulate a variety of components. For example, the generic subcircuit in Figure 1 and the corresponding listing model the simple linear behavior of a pressure transducer. Design by Debra Horvitz, Galahad Systems, Laguna Hills, CA
Spice Accepts & Displays Y Parameter - 08/04/94 EDN Design Ideas: Admittance or Y parameters have been the favorite of many high-frequency analog engineers for many years. Y parameters provide insights into circuit behavior not as apparent as with the more popular
parameters. Although
parameters suit single-stage designs, modeling techniques that are impedance independent--namely Y parameters--suit IC designs best. Design by Michael A Wyatt, Honeywell SSAVD, Clearwater, FL
Split or Single Supply Operation, Bidirectional Output into A/D - in this circuit, split supply operation is used on both the LT1787 and LT1404 to provide a symmetric bidirectional measurement. in the single-supply case, where the LT1787 pin 6 is driven by VREF, the bidirectional measurement range is slightly asymmetric due to VREF being somewhat greater than mid-span of the ADC input range. __ Linear Technology/Analog Devices App Note, Mar 31, 2010
Sprague TO-5 Tel-Ohmike capacitor analyzer manual w/schematic - Circuit Only __ Designed by Sprague
Sprague TO-6A Tel-Ohmike capacitor analyzer manual w/schematic - Circuit Only __ Designed by Sprague
Square Root Function Improves Thermostat - 09/30/99 EDN Design Ideas: Perhaps the most elementary rule of control-loop design theory is that feedback-loop performance is fundamentally linked to the careful choice—and stability—of loop gain. insufficient loop gain leads to poor setpoint accuracy. Too much gain can induce feedback instabilities, Design by W Stephen Woodward, University of North Carolina, Chapel Hill, NC
Standalone Digital Voltmeter Uses a Multichannel ADC - 11/15/12 EDN Design Ideas: Monitor several different voltages with one instrument. This Design idea was realized for voltage/current measurement on a four-channel analog voltage source but has wide use in many other applications. The design is based on the Atmel ATmega8-16AC microcontroller and the MAX1230 12-bit ADC (references 1 and 2). Although the microcontroller has an internal 10-bit ADC, it’s more efficient to use an external multichannel ADC than to multiplex more analog channels to the ATmega8-16AC differential ADC inputs Design by Branislav Korenko
Standalone LED tester - Description and schematic for a constant-current LED tester. it safely lights up standard through-hole and surface mount LEDs, while providing easy access to current and voltage measurements. __ Contact David Cook
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