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Sensors / Detectors: Automotive Circuits
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Automotive: 
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Last Updated: November 22, 2021 03:00 PM
Circuits Designed by Dave Johnson, P.E. :

Table Lamp with Auxiliary 12v Automotive Style LED Light - This circuit provides about one watt of non-isolated DC power for an automotive type 12v LED array lamp in addition to a standard incandescent table lamp. . . Circuit by Dave Johnson P.E.-July, 2006

Wireless RFID Smart Key Detector - The hobby circuit below was designed to indicate if a key held over the small coil of wire contains a 125KHz RFID chip.  These chips are often used in smart car ignition keys.  The left side circuit forms a 125KHz power oscillator, which drives the 680uH a . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

Capacitance Proximity Switch
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Links to electronic circuits, electronic schematics and designs for engineers, hobbyists, students & inventors:

Table Lamp with Auxiliary 12v Automotive Style LED Light -  This circuit provides about one watt of non-isolated DC power for an automotive type 12v LED array lamp in addition to a standard incandescent table lamp. . . Circuit by Dave Johnson P.E.-July, 2006

Tail/Brake Light Signal Cluster -  Designed at the request of several correspondents, the circuit is the merger of two existing designs already available on this site, namely: LED driven tail/brake Light Cluster and Brake Light Signal Module. __ Contact Flavio Dellepiane, fladello @ tin.it

Taxi Phone Automatic Dialler -  This project is a dedicated device.  it dials a single phone number when the handset is lifted.  There are two different modes of operation..  A slide-switch on the PC board allows the project to operate in automatic or manual mode.  if the switch is in "auto dial" mode, a pre-programmed phone number is  AUTOMATIC ALLY dialled when the phone is lifted.  if the switch is in "push to dial, "  the project dials the number when the phone is lifted and "push to dial" button is pressed.  This allows the phone to be used as a normal phone.   __ Designed by Colin Mittchel

The Alternator -  Also the car batteryand cables __ Designed by G.L. Chemelec

The Flashing Heart -  The Circuit Diagram is shown in Figure 1.  it consists of a 4047 low-power monostable/astable multivibrator, IC 1, used in the astable mode to provide the timing pulses to control the flash rate of the LEDs.  To accomplish the astable mode, pins 4, 5, 6, and 14 are connected to +12VDC and pins 7, 8, 9, and 12 are connected to ground__ 

Third Brake Light -  This circuit is NOT a pulser or flasher!  What's so special about this circuit? Well, the first third-brake light I installed I had to pull a wire from the Third Brake Light all the way underneath the carpet to the brake-pedal-switch and I thought it would be easier to pluck the signal of both brakelights via the trunk.  Bench-test your circuit first and apply power to the circuit,  __ Designed by Tonny Von Roon

Third Brake Light Pulser -  Several years ago these flashers were introduced in the automotive industry as part of the third brake light and contained strobe lights (and strobing continuously for the duration of pressing the break pedal) but got abandoned almost immediately sometime later because of the 'strobe' effect it has on some people.  This circuit has become obsolet since much better circuits are available these days without the 'lag' in between brakes caused by R4 and C3.  One of the circuits is listed below __ Designed by Tony van Roon  VA3AVR

Transistor Based Motorcycle Alarm -  Motorcycle Alarm Circuits:  This circuit features a timed output and automatic reset.  it can be operated manually using a key-switch or a hidden switch.  By adding an external relay, it will set itself automatically - and/or immobilize the machine - every time you turn-off the ignition.  it's easily adapted for a 6-volt system - so it will protect your "Classic Bike". - Now With Free SiMetrix Circuit Simulation.  __ Designed by Ron J.

Transistor Based Motorcycle Alarm -  Motorcycle Alarm Circuits:  This is an even simpler transistor based motorcycle alarm.  The circuit features a timed output and automatic reset.  it can be operated manually using a key-switch or a hidden switch.  By adding an external relay, it will set itself automatically - and/or immobilize the machine - every time you turn-off the ignition.  it's easily adapted for a 6-volt system - so it will protect your "Classic Bike". - Now With Free SiMetrix Circuit Simulation.  __ Designed by Ron J.

Turn-signal System for Motorcycles -  This circuit is based on the CMOS IC from Motorola, the MC14049UB Hex inverting Buffer.  Of course, the regular CD4049 can be used and is pin-for-pin compatible.  The 4049 is a 16-pin chip.  Maximum DC supply voltage should not exceed 18V.  The above diagram can replace your existing mechanical clicker.  The prototype worked excellently!  __ Designed by Tony van Roon  VA3AVR

Two CMOS Based Vehicle Anti-Hijack Alarms -  Automobile Alarm Circuits:  The first circuit is designed for the situation where a hijacker forces the driver from the vehicle.  if a door is opened while the ignition is switched on - the circuit will trip.  After a few minutes delay - when the thief is at a safe distance - the alarm will sound and the engine will fail.  The second circuit is a modification of the first - offering enhanced protection in many more situations.  __ Designed by Ron J.

Two LED trouble light system -  No circuit description, schematic only__ CdS Electronic

Two Simple Circuit Relay Based Motorcycle Alarms -  Motorcycle Alarm Circuits:  These are two - easy to build - relay-based alarms.  You can use them to protect your motorcycle - but they have many more applications.  if you use relays with 6-volt coils - they'll protect your "Classic Bike".  Both alarms are very small.  The completed boards occupy about half a cubic-inch - 8 cc.  The standby current is zero - so they won't drain your battery.  __ Designed by Ron J.

Two Watt Switching Power Supply -  in this small switching power supply, a Schmitt trigger oscillator is used to drive a switching transistor that supplies current to a small inductor.  Energy is stored in the inductor while the transistor is on, and released into the load circuit when the transistor switches off.  The output voltage is dependent on the load resistance and is limited by a zener diode that stops the oscillator when the voltage reaches about 14 volts.  Higher or lower voltages can be obtained by adjusting the voltage divider that feeds the zener diode.  The efficiency is about 80% using a high Q inductor.   __ Designed by Bill Bowden

Two-Zone Burglar Alarm -  Multi-Zone Burglar Alarm Circuits:  This two-zone alarm has automatic exit, entry and siren cut-off timers. So it has a particularly detailed circuit description.  There's an optional One-Time-Only module.  it will force the siren to switch off after the first ten minutes - and prevent the alarm from activating a second time.  __ Designed by Ron J.

Ultrasonic Parking Assistant -  The basic theory behind the Parking Assistant is the Sound Navigation and Ranging (SONAR) technique that is used for finding the distance and direction of a remote object underwater by transmitting sound waves and detecting reflections from it.  First, a series of short ultrasonic pulses are transmitted using a transducer that changes voltage into sound waves.  The transmitted pulse is reflected off an object, and the reflected wave is then received by another transducer that converts sound waves into voltage.  The transmitted signal is also known as the ‘ping’ and the received signal is known as the ‘pong’.  By counting the elapsed time between the ping and the pong, the distance between the device and an object can be easily calculated by multiplying the elapsed time with the speed of sound.  __ 

Ultrasonic ParKontroller -  Are you afraid that your brand new Hummer is going to get scratched while parking it in a tight space?  Do you have trouble backing your large Mercedez S-class into your small garage?  Fear no more!   Our ultrasonic ParKontroller can sense how far you are away from the wall __ Designed by James Juwon Lee and Maurico Rodriguez Saenz

UltraSonic Radar -  This is a very interesting project with many practical applications in security and alarm systems for homes, shops and cars.  it consists of a set of ultrasonic receiver and transmitter which operate at the same frequency.  When something moves in the area covered by the circuit the circuit’s   __ Contact IQ Technologies

Vehicle Anti-Hijack Alarm No.3 -  Automobile Alarm Circuits:  Like the first two Hijack Alarms - if a door is opened while the ignition is switched on - the circuit will trip.  And after a few minutes delay - when the thief is at a safe distance - the Siren will sound.  But this time the engine does not go on to fail automatically.  instead - it will continue to run until the thief turns off the ignition.  Then the engine will not re-start. __ Designed by Ron J.

Vehicle Loop Detector -  Another Simple But Very Effective Circuit __ Designed by G.L. Chemelec

Video: BMW's i3 Electric Car Fuels Up With a Home Depot Generator -  17-Sept-2014   Christen Costa Gadget Freak BMW's i3 is an impressive piece of kit.  The frame of the car you have a Gadget Freak project you would like the world to see? Send a brief description of yourgadget and a photo to Executive Editor Jennifer Campbell.  Check out the Best of Gadget Freak-- Volume__  Gadget Freak Video

Volvo 164 electric fan thermostat -  (Hand drawn schematic) While this circuit could be fitted to any vehicle, it was designed for use on my Volvo 164.  The original mechanically-driven viscous coupling fan had a loose centre bearing and made alarming clanking noises at certain revs, so rather than try and arse about finding a replacement I figured I'dfit an electric fan and possibly save an mpg or two at the same time.  __ 

Wide Band Fuel Mixture Display -  This document is an introduction to the Wideband Fuel Mixture Display (FMD).  __ 

Wide Input Range 1a LED Driver Powers High Brightness LEDs with Automotive & 12 VAC Supplies -  DN1012 Design Notes__ Linear Technology/Analog Devices

Windshield Wiper Delay -  The intermittent wiper circuit shown above causes the auto's windshield wipers to wipe once every several seconds instead of constantly wiping.  The circuit may be added to older cars to provide the intermittent function or it __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

Wiper Speed Control -  A continuously working wiper in a car may prove to be a nuisance, especially when it is not raining heavily.  By using the circuit described here one can vary sweeping rate of the wiper from once a second to once in ten seconds__ 

Wireless Auto Tachometer -  Anyone performing their own automobile tune-ups knows how important it is to know your engines speed.  With this tachometer, you can measure your engines speed without any connections or annoying timing lights.   __ Designed by Aaron Cake

Wireless bicycle brake light -  04/17/14  EDN Design Ideas:  The TI LDC1000 senses bike wheel rotation and controls a stop light.  My submission video shows the new Texas instrument's LDC1000 attached to the rear wheel fork of a bicycle, where it senses the spokes as the wheel rotates.  This proof-of-concept demonstration shows how perfect this sensor is for my goal of an improved bicycle brake light that has many advantages.  i'm passionate about getting this invention completed and on the market as soon as possible, where it can help prevent some of the many injuries and deaths to the hundreds of millions of the world's bicyclists each year.   Design by John Craig

Wireless RFID Smart Key Detector -  The hobby circuit below was designed to indicate if a key held over the small coil of wire contains a 125KHz RFID chip.  These chips are often used in smart car ignition keys.  The left side circuit forms a 125KHz power oscillator, which drives the 680uH a . . . Hobby Circuit designed by Dave Johnson P.E.-July, 2006

WWV Converter for the Car -  This converter allows an ordinary AM car radio to receive WWV at 10 MHz.  WWV transmits the precise time of day and the car is the most common place to need accurate time!  Other interesting stations near 10 MHz may also be received including those famous BBC news and science shows.  The unit should be constructed in a metal box with antenna connectors compatible with the car radio.   __  Contact:  Charles Wenzel of Wenzel Associates, Inc.


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