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Last Updated: December 31, 2017 06:44 AM

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
6 Models Available - Call 806-368-7747

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

Bugdozer Autonomous Mini-Sumo Robot -  Based on an MC68HC908GP32 microcontroller, this pulse-width modulated 18-volt dc scoop-on-wheels saw combat in November 2000.  Using two 38-kilohertz infrared sensors and 4-front/1-rear near-red phototransistors, Bugdozer tries to push opponents out of the ring while staying within the white borders herself.   __ Contact David Cook

Build a 10 Amp 13.8 Volt Power Supply -  Sometimes amateurs like to home-brew their power supplies instead of purchasing one off the shelf at any of the major ham radio retail dealers.  The advantage to rolling your own power supply is that it teaches us how they work and makes it easier to troubleshoot and repair other power supply units in the shack.  it should be noted that there is no real cost advantage to building your own power supply unless you can get a large power transformer and heat sink for a super low price.  Of course rolling our own gives us the ability to customize the circuit and make it even more reliable than commercial units.   __ Designed by N1HFX

Build a charge pump with ultralow quiescent current -  5-Aug-04 EDN Design Ideas:  Portable battery-powered devices often spend most of their life in standby mode, in which the quiescent current of an internal boost converter continuously bleeds the battery.  The quiescent current during standby can be larger than the actual load current.  Though several inductor-based converters offer maximum quiescent current of less than 10 µA, designers usually prefer or require a regu __ Circuit Design by Greg Sutterlin, Maxim Integrated Products, Sunnyvale, CA

Build a HamComm Data Slicer -  Until recently many of the ham radio operating modes required specialist equipment that most often had to by build and was exclusive to the task.  Enter the Personal Computer.  The PC made life a little easier for the ham as it was now able to take over some of the jobs that bespoke hardware did.  But it still wasn't quite there yet.  The task of the PC was mainly to be a 'front end' to a now multi capable bespoke box__ 

Build a hanging dipole for two metres -  ideal for the portable operator.  amateur radio construction projects.   __ Designed by Peter Parker

Build a Magnetic Field Immunity Tester -  You can assemble a precompliance (or even full compliance) magnetic field immunity test system in a few hours using common laboratory instruments, a 100-W audio amplifier, some white PVC Schedule-40 3/4-in.  water pipe, some wood, and a copper or aluminum sheet__ 

Build a negative-voltage power-side switch -  14-Oct-04 EDN Design Ideas:  When you need to quickly connect a negative power supply under logic control, the negative power-side switch in Figure 1 can help.  Although originally intended for driving the gates of high-current MOSFETs, the MIC 4451 can assume a different role.  it provide as complementary, low-on-resistance MOSFET switches to connect a system power-supply rail to a negative input voltage or to ground, enable __ Circuit Design by Michael English, Micrel Semiconductor, San Jose, CA

Build a PIC Controlled DDS VFO 0 to 6 MHz -  This is NOT meant as a detailed building instruction for a DDS VFO.  it is only a few fragments from my experimental work in the shack.  This is "as is" information.  it may contain errors.   However, my own prototype works very well. __ Designed by Johan Bodin, SM6LKM

Build a precise DC floating-current source -  08/18/05 EDN Design Ideas:  Use a general impedance converter and resistors to develop a specialized current source __ Circuit Design by D Ramírez, S Casans, C Reig, AE Navarro, and J Sánchez, University of Valencia, Burjassot, Spain

Build a Precision Deadband -  20-Feb-03 EDN Design Ideas:  Deadband circuits find applications in servo-control systems.  A precision current source and a half-wave inverting rectifier form a positive deadband circuit (Figure 1).  The REF01, IC 1, is a precision 10V voltage reference.  it forms a precision current source with the addition of a unity-gain buffer (IC 2A] and resistor R1 __ Circuit Design by V Manoharan, Kochi, India

Build a Simple Circuit Bat Detector -  The Simple Bat Detector is a frequency division type device.  Frequency division type detectors allow you to hear ultrasonic sound by digitally scaling the frequency down into the human hearing range.  For instance, a western pipistrelle bat emits ultrasonic sound in the range __ Designed by Tony Messina-Las Vegas, NV

Build a Simple Circuit Complementary-Bracket-Pulse Generator -  20-Aug-09 EDN Design Ideas:  When building push-pull switching power converters or motor controllers, you often need alternating pulses with a small amount of dead time between them to minimize simultaneous conduction in output-switching devices.  Switching controller ICs  have this feature, but they usually operate __ Circuit Design by Horst Koelzow, Global Thermoelectric, Calgary, AB, Canada

Build a Simple Circuit crystal set -  amateur radio construction projects.   __ Designed by Peter Parker

Build a Simple Circuit one-chip phototimer -  8-Jul-04 EDN Design Ideas:  Recently, I needed to automatically switch on a lamp when it became dark and keep it on for a given time.  Trying not to reinvent the wheel, I looked through what was available on the market, but I could not find an inexpensive device that satisfied the requirement.  Some products worked like a photoswitch, lighting a lamp when it becomes dark and keeping it on while it is dark—in other wor __ Circuit Design by Abel Raynus, Armatron International, Malden, MA

Build a Simple Circuit Serial Programmer for AVR Devices -  Note that the AVR910 programmer does not support all AVR processors, especially the newest chips.  Be sure to check the documentation to see if it supports the version (s) of the processor you are interested in __ Designed by Dick Cappels

Build a simple, soft-action muting switch -  14-Oct-04 EDN Design Ideas:  The circuit in Figure 1 adds a soft muting switch with power-up/power-down muting to a line-level audio circuit.  R4, C1, and JFET Q1 quietly ground a signal in 100 to 200 msec when you close S1 or release it when you open S1.  Potentiometer R2, set to twice Q1's cutoff voltage, makes the on/off transition times roughly equal __ Circuit Design by John Firestone, Bremerhaven, Germany

Build a Thermometer Kit -  Build your own modern thermometer. __ Contact Jameco Electronics

Build a transformerless 12V-to-180V DC/DC converter -  8-Jul-04 EDN Design Ideas:  Some transducers for portable or automotive applications need accurately regulated, high-voltage bias and draw little current.  To produce such high voltages from a low battery voltage, designers typically use switch-mode DC/DC converters—generally, flyback converters.  These converters exhibit high efficiency at medium or high output power __ Circuit Design by Francis Rodes, ENSEIRB/IXL, Talence, France

Build a UPS for USB Devices -  04/11/02 EDN Design Ideas:  Portable systems often include circuitry that derives power from an external source, such as USB.  When the system disconnects from the USB supply, a battery takes over and supplies current via a DC/DC converter.  A diode-OR connection (Figure 1) offers the easiest way to ensure that the supply voltage doesn't sag during this switchover to the battery __ Circuit Design by Mark Cherry and Jean-Claude Ailloud, Maxim Integrated Products, Sunnyvale, CA, and France

Build a USB-based GPIB controller -  112/06/05 EDN Design Ideas:  Roll-your-own USB-based instrumentation bus __ Circuit Design by Boštjan Glazar, Marko Jankovec, and Marko Topic, Laboratory of Semiconductor Devices, Ljubljana, Slovenia

Build an Adjustable High-Frequency Notch Filter -  02/06/03 EDN Design Ideas:  Although you can obtain universal, resistor-programmable switched-capacitor filters that are configurable as notch filters, most cannot operate at bandwidths higher than 100 kHz.  Further, the typically 16- to 20-pin packages do not include a continuous-time, antialiasing filter to prevent spurious signals from appearing at the output __ Circuit Design by John Ambrose, Mixed Signal Integration Corp, San Jose, CA

Build an O-Scope -  Ok idiots, here's the deal.  The base of this project is the guts of your every-day stinky, dirty, poor quality television that you don't want any more.  Since the tv has most of the stuff already inside it to function as an oscilloscope, it requires only a few modifications.  Beyond the TV, a variable frequency saw-tooth generator circuit and a few amplifier circuits are all that is required.  This is a fairly simple project, although I have to say the results I got aren't especially outstanding if you actually plan to use this thing for more than decoration.  But for someone with any sort of intelligence, it might just work __ Designed by Greg Miller

Build an RC Plane Finder -  The lost plane finder introduced here is a little on board beacon, also known as lost model alarm/crashed aircraft beacon, which helps you find a crashed or downed radio-controlled plane.__ Electronics Projects for You

Build the Lightning Bulb -  The Lightning Bulb circuit uses a quadrac (see Fig.1) --a device that combines a TRIAC and a diac trigger in a single package--to control the supplied current.  Figure 1A shows the schematic symbol for the quadrac, while figure 1B shows the pinout for the unit used in our circuit.  Note that quadracs are increasingly difficult to come by;.   __ Designed by Vincent Vollono

Build this add on Capacitance Meter -  This simple add-on capacitance meter has been specially designed to help you identify capacitors from 1p to 10u.  There has always been a problem identifying capacitors, due.   __ Contact Collin Mitchell

Build this Negative Ion Detector -  Figure 1 shows a schematic diagram of the ion Detector--a rather simple circuit consisting of three transistors (two PN2907 PNP, and a single PN2222 NPN type) , three resistors, one capacitor, an antenna, a mA meter, and an LED __ Designed by Vincent Vollono

Build your own 89C51 PABX -  This 89C51 PABX project is basically an eight line intercom from which you can call one to eight numbers.  The 89C51 PABX system also supports dialling and receiving telephone calls.  __ 

Build your own bypass-capacitor tester -  12/06/01 EDN Design Ideas:  Most circuits use bypass capacitors and can deliver substandard performance if the capacitors have poor pulse characteristics.  Few if any articles cover how to test bypass capacitors for pulse characteristics.  The circuit in Figure 1 tests these characteristics.  it charges the capacitor under test through 100 kU for approximately 1 msec and then discharges it through 10U for a __ Circuit Design by Carl Pugh, Pugh Magnetics, Newark, CA

Build your own High-Voltage Capacitors -  As one who supplies parts to those who experiment with high voltage, I get a lot of letters and phone calls from frustrated builders that go like: "Can you supply an inexpensive xxx microfarad capacitor at a working voltage of YYY? My only source wants $249 for one.  "Sometimes, a high price is justified; other times, a seller has the only capacitors of a special value available, and will soak you for the maximum dollar __ Designed by Tony van Roon  VA3AVR

Build your own IrDA SIR Transceiver (Dongle) using MCP2120 -  How to build your own iRDA SiR Transceiver (Dongle) for Linux using the MCP2120 __ Designed by Felix Tang

Build your own Joysticks & Controllers -  Building your own normal PC joystick is not economically wise, but if you can't find a joystick you would like to have, then you have te consider doing it yourself.  The connections inside PC joystick are quite simple to do, the harder part is the mechanics.  Buttons are quite easy to mout to the case you use when you select suitable buttons, but the problematic __ Designed by Tomi Engdahl

Build your own laboratory precision voltage reference -  05/24/07 Video Design ideas-EDN    Mark Thoren, mixed-signal application engineering manager with Linear Technology, demonstrates an amplifier-based Circuit design for a relatively inexpensive precision voltage source.    __ Circuit Design by Mark Thoren, mixed-signal application engineering manager with Linear Technology

Build your own LED cube -  This month's featured Gadget Freak is provided by an old favourite of the blog, Peter Griffiths.  He shares all the details necessary to build your own 5 x 5 LED cube__ 

Build your own LF/Audio instruments -  Devoted entirely to Amateur radio.   __ Designed by Jan-Martin Nřding

Build Your Own Popcorn Strobe -  Mini 555 Monostable circuit creates big fun. __ Contact Jameco Electronics

Build your own Q Meter project -  This article appeared in the January/February issue of Amateur Radio (the journal of the Wireless institute of Australia) and is reprinted here for the convenience of others. (Aussies who are not members of the WiA are urged to join our new streamlined national body- it is the only way we have of defending our spectrum allocations against an increasingly greedy mixture of government and private enterprise). __ Designed by VK5JST / VK5TR

Build Your Own Solar Battery Charger -  For this project I used 12 cells but you really only need 6.  So if you are on a budget use 6 but if you want a fast charger use 12.  Next lay out all your cells on your window to make sure everything is going to fit.  I used the "deeper" side of the window so that there would be more room__ 

Build your own superheterodyne receiver -  08/01/1996  EDN Design Ideas:  :      Easy to build, 2 chip Superhetrodyne for the aircraft band.  Cell phones aren't the only devices to benefit from ever-smaller and more highly integrated communications-IC  technology.  The simple, three-IC  superheterodyne radio in Figure 1 can receive stations in the 4.5- to 10-MHz range from around the world with only a 10-ft antenna.  A superheterodyne radio works by mixing the incoming RF signal with a local-oscillator (LO) signal to produce an iF. __ Circuit Design by Steven Hageman, Hewlett-Packard, Santa Rosa, CA

Build your own UFO Bino-Scope unit-upgrade binoculars to become a photosensitive bino-scope -  Something wehave always wondered regarding UFO sightings.  Say its night, and you see a light in the distant sky.  is it really an airplane? Or suppose it's behaving oddly, performing maneuvers impossible for an aircraft, etc.  Could the optical emissions coming from that object be identical to an ordinary 120V AC lightbulb? Specifically, is the LiGHT AMPLiTUDE of that object pure and smooth DC? Or is it some kind of AC white noise or signal?__ 

Build Your Own Ultra-Low-Cost Isolated DC-DC Converter -  When low cost in small volumes using readily available parts is a primary concern, standard approaches to isolated dc-dc conversion may not be suitable.  integrated switchers from , integrated Products , National __ Designed by Dwayne Reid

Build Your Own Video-Rate 2-photon Microscope -  Two-photon (2-P) microscopy offers several advantages for biological imaging - In particular for non-injurious imaging of dynamic cell behaviors deep within intact tissues, organs and even the living animal [Cahalan et.  al., 2003, Stutzmann et al., 2005].  However, its widespread adoption for such applications has been hindered by two factors: commercial 2-P microscopes are very expensive, and they typically acquire images at frame rates too slow to resolve many biological processes.  Both of these problems may be circumvented by building your own 2-P microscope!  __ Contact ianparkerlabweb @ gmail.com

Building a Hardware Random Bit Generator -  The noise source is a transistor operated in base-emitter reverse biasing.  it needs at least 9 volts to generate noise, so a voltage doubler is used (constructed around the 555 timer IC ) to ensure that the voltage is sufficient even with low battery power.  The white noise signal is amplified in the two following transistor stages, and finally fed into a shmitt-trigger to get a digital TTL level signal.  The second schmitt-trigger drives the LED which indicates the presence of an output signal.__ 

Building an Intel 8008 Computer Clock -  About every year I design and build a new clock.  This year’s project is a clock based on an intel 8008 first generation 8 bit microprocessor.  Because it is a fairly unique project i’m putting more effort into the documentation __ Designed by Len Bayles

Building an RF Remote Control System -  With a handful of inexpensive components, a little creativity, and the power of PicBasic, you can build some pretty outstanding robotics creations as Rob Arnold proves with his Ruf-Bot project.   __ Designed by Rob Arnold

Building thes -  The fastest way to put a circuit together is on BREADBOARD.  The cheapest and best bread-board has power-rails and sets of "tie-points" or "holes" as shown in this photo__ 555-Timer

          >>>       This is the last page of #'s - B

Electronic Construction Projects: 
#'s - B         C - D         E - G        H - K         L - P         Q - S         T - Z

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

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