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Last Updated: December 01, 2017 03:41 AM

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

A 24V/48V Hot Swap™ Controller -  DN226 Design Notes__ Linear Technology/Analog Devices

A 25 LED Chaser (Sequencer) -  A Fairly Simple C-Mos Circuit.   __ Designed by G.L. Chemelec

A 250-amp Speed Controller for RC cars -  Radio Controlled cars have increased in popularity from the time when they were first introduced.  Initially, they were little more than toys.  Now they have matured to an international sport.   __ Designed by Collin Mitchell

A 3-Channel UHF Rolling-Code Remote Control, Pt.1 -  This high-security 3-button UHF transmitter and receiver can be used for keyless entry into homes and commercial premises and for controlling garage doors and external lighting.  Three separate outputs on the receiver can be used to activate various electrical devices such as a door strike, a motorised garage door and 230VAC lights.  Up to 16 transmitters can be used with the one receiver so it's even suitable for a small business.__ SiliconChip

A 4-Digit Keypad Controlled Switch -  Universal Keypad-Controlled Switches:  This is a Universal version of the Four-Digit Alarm Control Keypad.  I have modified the design to free up the relay contacts.  This allows the circuit to operate as a general-purpose switch.  I've used a SPCO/SPDT relaybut you can use a multi-pole relay if you wish.  __ Designed by Ron J.

A Ballast that can Be Dimmed from a Domestic Phase Cut Dimmer. -  A system has now been developed, based aroundIR2156, whereballast is able to operate with minimal flicker over a considerable portion ofadjustment range of a dimmer andlight output may be controlled over this range from maximum output down to around 10%.  

A Better Volume Control -  A volume control using a linear pot that is much better than most log pots __ Designed by Rod Elliott  ESP

A Cat or Dog Detector for Pet Door -  This circuit uses one tuned coil for on the door and just a single wire loop on the animals collar.  When the two coils come close together, it produces a signal that can cause a an LED to light and also trips a solenoid to unlock the door so it can open.  Since all these doors are somewhat different, I leave __ Designed by G.L. Chemelec

A Current Limiting Bench Power Supply -  Power Supply Circuits:  This is a 1-amp variable-voltage PSU.  It adjusts from about 3v to 24v: and has the added feature that you can limit the maximum output current.  This is invaluable when   (for example) you power-up a project for the first time or soak-test a piece of equipment.  __ Designed by Ron J.

A doozy requiring some parts you can't get at the 'Shack. -  You can make a doozy of a xenon strobe using the 12 volt DC in, DC output mercury lamp ballast here at http://www.  donklipstein.  com/ebdc12.  html.  You may run into a problem with the flashtube arcing continuously after a flash.  If you use an open-collector comparator such as a 339 in the overvoltage sensing section of this circuit, you can wired-AND the comparator output with some sort of scheme to disable the circuit for a few to a few tens of milliseconds after a flash   (by "pulling down" Pin 5 of the 555).   __ Designed by Don Klipstein

A Dual Alternating Flashing Light -  This project is best for mounting on a layout to light a crossing or ring a bell.   __ Designed by ML Rollins

A Dual Tandem Flashing Light-Powered by a 9 Volt Battery -  This circuit is powered by a 9 volt battery, suitable for warning lights on a tall structure.    (Personally, I can't recommend you buy anything but the Rollins Railroad Designs kit; for $4.00 you can't go wrong.  The 555 IC is about $1.50 by itself at Radio Shack).  If you choose to buy all the parts yourself, realize you need ONLY two LEDs, not two of each; you should be able to mix and match colors.   __ Designed by ML Rollins

A Few Added Components Make a Self-Contained Controller for 100A LoA - D -  EDN-Design Ideas 12/15/11    Add a few components and you have a stand-alone piece of test gear.   __ Circuit Design by Steve Hageman, AnalogHome/com, Windsor, CA

A for mains synchronization has two separate outputs for each half-period -  EDN-Design Ideas 03/22/2013    Generate independent short pulses at positive- and negative-going AC mains zero crossings. __ Circuit Design by Dusan Ponikvar

A High Speed NiCd Charger for Electric R/C -  A few years back, I published a design for a Low Cost Thermal Peak Detection Charger.  Since then, I've designed several other chargers, in my ongoing quest to avoid having to spend money.  Of course, in building all these designs, I've probably spent more than a really good commercial charger would have cost me.  But designing and building is half the fun __ Designed by Stefan Vorketter

A High-Quality DAB+/FM Tuner, Pt.1 -  We know you've been waiting for it and after more than a year in development, we are delighted to present this world-first high performance DAB+/FM stereo tuner design.  It has all the bells and whistles of DAB+ in a sleek pro-quality case, with all features accessible by remote control.__ SiliconChip

A High-Quality DAB+/FM Tuner, Pt.2 -  Last month, we introduced our new DAB+/FM Stereo Tuner and gave the circuit details.  This month, we show you how to assemble the two PC boards and install them into a low-profile steel case.__ SiliconChip

A High-Quality DAB+/FM Tuner, Pt.3 -  In this month's final part, we explain how to use the DAB+/FM Stereo Tuner and describe the menu system.  We also show you how you can upgrade the firmware if necessary and describe various features of the tuner in detail.__ SiliconChip

A Logic-Level actuated gas solenoid for starting propane -  Despite exhaustive searching, every reasonably priced solenoid valve for controlling propane during pushbutton start required 12VDC, beyond the capabilities of a normal pump battery.  I know that there are methods to generate HV pulses which will actuate the solenoid, which will remain closed down to below 5V, but I went the more expensive and reliable route with a DC-DC converter, shown here, the Newport NMR101.  R2 is 10K, and R3 is 100K.  R1 is 39 ohms.  Vary R1 to acheive reliable closing of the valve and to keep current to ~90 mA through the solenoid.  The converter will draw 260 mA from the 5V source.  

A Logic-Level actuated, adjustable glow-plug driver -  All of my turbine starts before the research on the ECU involved a very successful spark ignition.  I thought   (only briefly) of trying to add spark ignition to the ECU, but the mixture of delicate logic circuitry and perhaps 30, 000V simply don't mix.  My past experience with the hall sensor ignition for the radial engine bears this out in painful detail.  So I decided to go with a glow-plug driver.  

A Low Battery Cutoff -  Also acts as a Master On / Off Switch.  NOW, Also a New P-Mos Version.  Supplies Positive voltage to grounded devices.   __ Designed by G.L. Chemelec

A Low Cost Thermal Peak Detection NiCd Charger -  The electric model aircraft and car industries have produced a bewildering array of field chargers for NiCd motor battery packs.  These range from simple 6 or 7 cell chargers consisting of a resistor and mechanical timer, to more complex chargers with peak detection, cycling, and the ability to handle 36 cell packs __ Designed by Stefan Vorketter

A mad idea for a blacklight strobe -  CAUTIONMay be both hard on your eyes and a bit disappointing __ Designed by Don Klipstein

A Miniature High-Rate Speed Control with Brake -  Many designs for high-rate speed controls have been published.  Most require two 8-pin integrated circuits   (ICs) or one 14-pin IC.  Many designs suitable for home construction are fairly large   (some as large as 2" square).  Many do not include a brake __ Designed by Stefan Vorketter

A Neon Tube Modulator for Cars -  Simple circuit connects to the sub-woofer output and modulates a neon light to the beat of the bass__ SiliconChip

A New Thermostat Control for Electric Heaters -  One Advantage of these two units is the Sensor can be placed Away from the heater, therefore sensing the Actual Room temperature, not the direct heat from the heater.  These can also be used in a confined space with a Heat Lamp, to create a Drying Oven  __ Designed by G.L. Chemelec

A PID Temperature Controller -  What's a PID controller? PID stands for "proportional integral differential" and relates to a process which seeks to continuously correct the error between a measured variable and a desired setting by calculating an appropriate correction process.  In practice, it can largely avoid the large overshoots and undershoots that occur in simple temerature control systems.__ SiliconChip

A Quick-and-Dirty DC Motor Controller -  31-Oct-16 -Design News:   Years ago my pal Steve Titus wanted to experiment with some drone rotor designs.  He needed a simple motor controller that could operate from 8V to 12V and deliver amperes of current to a DC motor used in radio-controlled aircraft (figure 1).  I whipped out a design based on the classic TL494 PWM ( __ Gadget Freak

A Receive Signal Decoder -  The signal output byradio control receiver is a form of PWM.  This may be useful for driving servos, but is inconvenient for general electronic applications.  Therefore, several of circuits on this site convert this signal into a voltage first.  This is performed by this circuit.  It is not a project in its own right, just a building block used by or projects __ Designed by Paul Hill

A Remote Telltale for Garage Doors -  If you have a perfect memory you won't need this.  But the rest of us could find it very handy! It lets you know if you've left the garage door open without stumbling out in the dark or the pouring rain...__ SiliconChip

A repetitive trigger -  Based on the 555 timer IC, useful for strobe lights.  A bit on the 4017 counter IC for multiple flashes and sequences of flashes __ Designed by Don Klipstein

A Rolling Code 4-Channel UHF Remote Control -  It has a long range, its rolling code is virtually unbreakable, it uses a keyring transmitter and it's ideal for use with garage door controllers.__ SiliconChip

A Serial Infrared Remote Controller -  This is a simple, cheap device that can be connected to any serial port to control most components that have infrared remote controls.  I designed and built it   (on a solderless breadboard) in 1991.  In 1992 I wrote a lengthy description of it for an electronics class.  In 1994 I finally designed a PC board for it, using a free, X-based PC board design program called pcb, and in 1995 I etched several of the boards and made the final product __ Designed by John DuBois

A Servo with lots of grunt -  Looking for a servo with a lot of grunt? This jumbo servo uses a robust 12V motor/gearbox assembly to give you real muscle.__ SiliconChip

A Simple Circuit 74*245-based Motor driver -  A simple, time-honored approach is to use one or more 74*245 chips   (normally the 74AC245 is used for maximum current capability) to provide motor drive current.  Here, each channel of drive power is provided by one or more buffer on the chip.   __ Contact: Eric Seale

A Simple Circuit Light Control Switch -  This is a simple LM311 Comparator based switch which can be used for various purposes: __ Designed by Nina Gajjar

A Simple Circuit light flashing -  This circuit use 2 transistor and some components.  

A Temperature controlled TRIAC for a fan -  Schematic only __ Designed by G.L. Chemelec

A Temperature Sensor Control -  A basic circuit using Diodes to detect temperature differences __ Designed by G.L. Chemelec

A Thermistor Temperature Controller -  Schematic only __ Designed by G.L. Chemelec

A Thermostat Control for Electric Heaters -  One Advantage of these two units is the Sensor can be placed Away from the heater, therefore sensing the Actual Room temperature, not the direct heat from the heater.  These can also be used in a confined space with a Heat Lamp, to create a Drying Oven  __ Designed by G.L. Chemelec

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