Making a Simple Circuit effective whisker bumper - Several Projects, scroll down.    We all have need of that last line of defense when the SONAR glitches, the IRPD doesn't and our bot is on a collision course with a table leg.  That last defense against re-kitting is a bumper.  I have made a few from microswitches, miniswitches and other things - usually they work, sometimes they need too much force to work and "ugh" collision.  This example is another type of sensor that doesn't use a switch, its parts are super cheap and it works just great.  Its a "whisker" bumper.  Here are the parts you need to build one too.  ____ Designed by Dennis Clark

Mini-Contoller - Speedcontrollers for Model-Aircrafts with BEC

Model Aeroplane Navigation Strobe/Battery Level Indicator - If you are interested in model aeroplanes and have the capital, a radio controlled electric park flyer is a must have.  An RC aeroplane under 400 grams floats around like the rubber models of my youth and contact with the ground doesn't seems to involve that sickening crunch __ Contact: r dot p @ webone.com.au

Model Railroad Camera Car - Schematic + Info + pictures __ Designed by Lennie Zink

Model Railroad Vacuum Cleaner This is an HO gage railroad track cleaner/vacuum car! - Schematic + Info + pictures __ Designed by Lennie Zink

Model Railway Level Crossing Lights - The level crossing warning lights are switched on automatically as a train approaches.  First an amber light shows, then two red lights flash until the train has passed the crossing.   __ Designed by John Hewes

Model Railway Short-Circuit Beeper - Short circuits in the tracks, points or wiring are almost inevitable when building or operating a model railway.  Although transformers for model systems must be protected against short circuits by built-in bimetallic switches, the response time of such switches is so long that is not possible to immediately localise a short that occurs while the trains are running, for example__ R. Edlinger - © Elektor Electronics Magazine

Model Railway Signal - This signal is controlled automatically by a passing train fitted with a magnet.  It can also be manually set to red or green by pressing the switches.  Trains will automatically stop at the red signal.   __ Designed by John Hewes

Model Railway Time - Here is a circuit that will convert any clock mechanism into Model Railway Time.  For those who enjoy model railways, the ultimate is to have a fast clock to match the scale of the layout.  This circuit will appear to "make time fly" by turning the seconds__ 555-Timer

Model Railway Turnout Control - This small circuit can be used to control model railway turnouts operated by AC voltages.  A logic level in the range of 5–12 V can be used as the control signal.  The coils of the turnout are switched using TRIACs.  Changes in the logic level of the input signal are passed on by the buffer stage built around T1 and T2.  The buffer stage is included to boost the current available at the gates of the TRIACs__ Hans Zijp - © Elektor Electronics Magazine

Model Rocket Altimeter - Circuit Only

Model rocket launch controller - The secrets to a successful launch controller are thick cables, power through a relay, and a beefy battery  (such as a lead-acid motorcycle battery) .  Learn what is inside a low-end commercial rocket launcher, how to make your own simple launch controller, and take a look at a fancy rocket controller that includes covered pilot switches and a switch lock.   __ Contact: David Cook

Model rocket launch Controller - Most commercial rocket controllers available to buy are either expensive or do not have many features.  After a lot of searching I found nothing that met my needs.  I wanted a controller that could work multiple pads, as well as being easy to set up and pack away, so I designed my own.  It has the ability to control up to 8 pads through a 6 core cable.  You may __ Designed by Andy Collison

Model Rocket Launcher - A schematic diagram of the Time Delayed Launch Control is shown in Fig.1.  The circuit – which gives a choice of 6 day settings – is comprised of three 555 timer/oscillators  (U1, U2, and U3) . __ Designed by Tony van Roon  VA3AVR

Model Rocket Strobe - Launch a model rocket on the darkest night and find it in a flash no matter where it lands! __ Designed by Anthony Charlton

Model Train Diesel & Horn Sound Module - A good friend of mine having just retired acquired as a gift a small gauge miniature train set and asked me if I would design something to simulate a diesel electric sound and horn for it.  Looking for shortcuts I researched many already-published designs most of which used a digital transmitter and receiver.  Dissatisfied with all of them I decided to design a system for universal application for any system up to 20 volts. __ Designed by © Laurier Gendron, Burnaby, B.C., Canada

Model Train Horn (2-tone) - With this circuit you can electronically simulate the noise of a diesel-train horn.  The sound is triggered automatically as the train reaches a desired place on the track so you can produce the sound as the train approaches stations, level crossings, etc.  The circuit can be built simply by using one 556 or two 555 timers __ Designed by Tony van Roon  VA3AVR

Model Train Lighthouse Flasher - HO train sets often have authentic looking scale model homes and buildings.    A while back someone asked me to design a flashing LED light, which he could mount inside a model lighthouse and have it operate so it would appear to rotate and flash.    I designed a working circuit but I was never pleased with the results.    I’m still not 100% pleased but the revised circuit below seems to operate a bit better than the older circuit.  … [ . . . Hobby Circuit designed by Dave Johnson P.  E.  , May 2012] . . . Hobby Circuit designed by David Johnson P.E.-December, 2012

Model Train Lighthouse Flasher Revisited - This was originally designed for a model in a HO train set.  It simulates the behavior of the light from a lighthouse.  The LED intensity gradually increases, then flashes with a bright light and finally decreases slowly in intensity . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

Moderately complex train Detector using an infrared LED & an infrared Detector - Since this Web page was originally posted, I heard from several people - and found about it personally - that Radio Shack had changed the parts in the infrared emitter/detector kit, part number 276-142.  Unfortunately, each part was not clearly labeled; I even found one kit  (example 2 below) where it's not easy to tell the emitter from detector.  Basically, check the parts out closely, and match them to what I've designated as either style 1, 2 or 3. __ Designed by ML Rollins

Motor Walker - An overview of the P5v2 walker electronics by Wilf Rigter __ Designed by Wilf Rigter

Multi Launcher for Model Rockets - This launch controller can be used with low voltage battery igniters, which fire rocket engines in model rockets such as the Estes range.  These circuits are electrical, only switches and contacts are involved.  First the circuit for a single rocket.   __ Designed by Andy Collison

Nest Box Technology - That's how it looks like under the roof behind the plexiglass of my Great Tit Nest Box: a little b&w camera and an electronic prototype board are fixed here.  You can see the infrared light emitting diodes  (IR-LEDs) around the camera lens, that's why the box is always as bright as daylight __ Designed by Manfred Boehmel

One IC 2 Tones Siren Double Tone Police Sound Single Tone Old AM bulance Sound - This circuit is intended for children fun, and is suitable to be installed on bicycles, battery powered cars and motorcycles, but also in models and other games.  With SW1 positioned as shown in the circuit diagram it reproduces the typical dual tone sound of Police __ Contact: Flavio Dellepiane, fladello @ tin.it

One ounce rocket ejection timer - This page describes the how to build a very small  (1.5"x1.5", ~1 oz.) rocket ejection timer.  I have tired to give as complete of instructions as possible, but you still might encounter problems.  While it is possible to build this timer without printing a custom circuit board, I don't recomend it.  In the past I __ Designed by Jonny Dyer

Pad launch controller for Model rockets - About six months ago I started thinking about the possibility of building a new launch controller that the club could use at it’s monthly launches.  This was partly
as a result of a discussion that occurred on the MASA mailing list related to ways to improve the regular launches (optimum number of pads, pad rotations, etc) and also as a result of having access to a large number of surplus components that could be used in the design and construction of a new system __ Designed by Steve Robb

PC Controlled RC car construction project - See the Programmable RC Car article for an updated version of this project. 
This project article was originally written in 2004 when most computers had parallel ports.  This is no longer the case, so much of this information is now outdated__ John Bennet

PC-Based Wireless Control for Toy Car - Here we show how you can control a toy car through your PC’s serial port using a pair of ASK transmitter and receiver modules. The received signal is decoded by a...__ Electronics Projects for You

Phase Shift Radio Direction Finder - Similar to the system used in modern aviation where an antenna array modulates the phase of an incoming signal.  The commercial system is known as Commutated Aerial Direction Finding  (CADF) where a ring of 18 identical antennas are each switched on in sequence, just like winding a rotary switch round and round so that one antenna is always connected to the receiver.   __ Designed by Harry Lythall-SM0VPO

PIC-Bot II using Microchip PIC16LF84 - On this page I hope to provide more details than I usually provide for those who wish to construct their own PIC-bot, realising that people actually try to make this stuff.  Traditionally, my 'bot pages are for documenting the essentials, not in the kind of detail needed to make as if it were a kit.  I document my projects bugs and all, but the simple PIC-bot needed to be worked out.  The original 5x platform was too complicated and required too much equipment to translate into how-to steps, this new PIC-bot is much easier to contruct, program and document.  I'm loving it already.  No more UV! __ Designed by Terry Newton

Pine Racecar Victory Judge - I have received countless emails asking for a circuit to tell the user which car won in a pine car  (also called Pinewood Derby, Cub Car, Scout Car, etc.) race.  This simple circuit takes care of the guesswork, lighting the appropriate LED to indicate the winner. __ Designed by Aaron Cake

Plane Motor Controller with High-Rate ESC, BEC & Brake - This electronic speed control  (ESC) for brushed motors combines the features of two of my earlier designs.  One was a high-rate 30A ESC with a brake, and the other a high-rate 12A ESC with a BEC  (receiver battery eliminator circuit) .   __ Designed by Stefan Vorketter

Power Supply - Schematic + Info + pictures __ Designed by Lennie Zink

Precision Digital Altimeter - The current concept incorporates a wireless transmitter and receiver and is thought to be used for remote controlled airplanes or appliances with two separate parts.  In other words, we have one dedicated transmitter  (acquisition, filtering) and one dedicated receiver part  (user-interface, look-up table, calibration, storage) , capable of being connected

Precision Receiver Battery Low Voltage Alarm - Flying hand launch gliders means living with small capacity receiver NiCad battery packs.  These small packs are light, but have the distinct disadvantage of rapidly depleting.  You can carefully time your flights, but you end up either crashing when your plane seizes or using only a portion of the already small capacity of the battery.  If you charge the battery in a slightly suboptimal fashion, your plane dies and bites the dirt  (done that, crashed) .  This devices will allow you to use a small mA pack and use the full capacity of your battery. __ Contact: IQ Technologies

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