http://www.bowdenshobbycircuits.info/ Bowden's Hobby Circuits [usflag] A small collection of electronic circuits for the hobbyist or student. Site includes 100+ circuit diagrams with text descriptions, several electronic calculators, links to related sites, commercial kits and projects, newsgroups, and educational areas. Most of the circuits can be built using common components available from Radio Shack, Digikey, Jameco, Mouser, Allied electronics, or salvaged from scrap electronic equipment. Most circuits have been built, tested, and believed to perform as described, however possible mistakes may be found. What's New Here? (09/15/16) +-------------------------------------------------------------------------------------------------+ | Digital/ | | | Computer | | | | | | * 16 Bit PC | | | Serial Port | | | Receiver | | | (CMOS) | | | * 24 bit ISA | | | card Installs | | | into your | | | computer. | | | Parts, plans, | | | schematics and| | | programmng | | | available. | | | Also may be | | | purchased as a| | | kit. | | | * 32 Bit Serial | | | Receiver (57.6| | | K Baud TTL & | | | CMOS) | | | * Parallel Port | | | Relay | | | Interface | | | Circuit | | | * Reading Data | | | From The | | | Parallel Port | | | * 1 Second Time | | | Base From | | | Crystal Osc. | | | * 32.768 KHz | | | Oscillator | | | Using A Common| | | Watch Crystal | | | * Digital | | | Electronic | | | Lock | | | | | | Telephone | | | Circuits | | | | | | * PIC Security | | | System Dials | | | Your Cell | | | Phone | | | * Use Old | | | Telephones as | | | Intercom | | | * Telephone | | | In-Use LED | | | Indicator | | | * Telephone | | | In-Use Relay | | | Circuit | | | * Telephone Ring| | | Generator | | | Using 60Hz | | | Power | | | Transformer | | | * Telephone Ring| | | Generator | | | Using | | | Switching | | | Power Supply | | | * Telephone | | | Audio | | | Interface | | | | | | LED Circuits | | | | | | * Philips RC5 IR| | | decoder using | | | 12 leds | | | * 1.5 Volt Dual | | | LED Flasher | | | * 40 LED Bicycle| | | Light (555 | | | Timer - 6 | | | volt) | | | * 28 LED Clock | | | * 72 LED Clock | | | * 10 to 100 LED | | | Sequencer | | | Using a Matrix| | | * PIC Digital | | | Clock Timer | | | * PIC Digital | Power Circuits | | Timer (4 timed| | | outputs) | * Discrete Low Dropout Regulator. | | * Binary Coded | * Buck Converter (1 watt LED driver) | | Decimal (BCD) | * Boost Converter For Solar Cell Array | | Clock | * Simple Variable Voltage Source | | * Digital LED | * LM317 Variable Voltage Regulator | | Clock and | * LM317 Regulator With Pass Transistor | | Timer | * Variable 3 - 24 Volt / 3 Amp Power Supply | | * Astable | * Variable Voltage and Current Power Supply | | Multivibrator | * Lithium Ion Battery Charger using a 555 Timer, LM339 and TL431 | | * Expandable 16 | * Lithium Ion Battery Charger Using a TL431 And Single Transistor | | Stage LED | * 2 watt switching power supply | | Sequencer | * Low Power DC to DC Converter | | * Descrete | * Constant Current Battery Charger | | Multistage | * 120VAC Lamp Chaser Using Solid State Relays | | Light | * 120 VAC Lamp Dimmer (full wave SCR) | | Sequencer | * Varying Brightness AC Lamp | | * 16 Stage | * 12 Volt Lamp Fader (Automatic) | | Bi-Directional| * 1.5 Hour Lamp Fader (Sunset Lamp) | | LED Sequencer | * Sunrise Lamp using 120VAC 60 Watt Lamp | | * 10 Stage LED | * 12 Volt Lamp Dimmer (using a pot) | | Sequencer | * Automobile Interior Light Fader | | * 18 Stage LED | * Interfacing 5 volt CMOS to 12 volt loads | | Sequencer | * Low Voltage , High Current Time Delay Circuit | | * 9 Second LED | * High Current Regulated Power Supply | | Relay Timer | * Thermostat for 1KW Space Heater (SCR controlled) | | * 9 Second | * Thermostat for 1KW Space Heater (Solid State Relay controlled) | | Digital | | | Readout Timer | Miscellaneous | | * Two Transistor| | | LED Flasher | * Neodymium Magnet Single Pole Motor | | * 1.5 Volt LED | * The Perpetual Swinging Pendulum | | Flashers | * Triangle and Squarewave Generator | | * LED Photo | * Transistor Schmitt Trigger Oscillator | | Sensor Circuit| * Descrete Set/Reset Flip Flop | | * Fading Red | * Discrete Bistable Flip Flop | | Eyes | * High Current MOSFET Flip Flop With Debounced Pushbutton | | * Descrete LED | * Monostable Flip Flops (one shot) | | fading circuit| * Ignition Coil High Voltage Circuit | | using 5 | * Ignition Coil Buzz Box | | transistors | * Capacitor Discharge Ignition Circuit | | * PIC controlled| * Generating Long Time Delays | | Fading Eyes | * Flashing Neons (NE-51 / NE-2) | | * 12 Volt Lamp | * Sequencing Neons (NE-51 / NE-2) | | Fader (LEDs or| * 555 Tone Generator (8 Ohm Speaker) | | incandescent) | * Generating Negative 5 Volts from 9 Volt Battery | | * LED Battery | * Touch Activated Lamp | | Condition | * Game Show Who's First Indicator Lights | | Indicator | * Salt Water Battery | | * 3.6 Volt (cell| * Transistor, Diode, IC outlines | | phone) LED | | | Battery Meter | Circuits Controlling Relays | | * 8 Stage LED VU| | | Meter | * IR Receiver Toggle Switch | | * Battery Equal | * Decoded IR Toggle Switch using the PIC12F629 | | Charge | * Relay Toggle Circuit Using a 555 Timer | | Indicator | * Relay Toggle Circuit Using a 556 Timer | | * IR Remote | * Relay Toggle Circuit Using a Single Transistor and Push Button | | Control Tester| * Relay Toggle Circuit Using a MOSFET and Push Button | | * IR Remote | * CMOS Toggle Flip Flop Using Push Button (CD4013) | | Control Tester| * CMOS Toggle Flip Flop Using Laser Pointer | | using a IR LED| * 555 Timer Monostable Circuit Using Pushbutton | | * AC Line | * Generating a Delayed Pulse With a dual 555 Timer | | Powered LEDs | * Light Activated Relay (toggled) | | * Line Powered | * Photo Electric Street Light | | White LEDs | * Power-On Time Delay Relay Circuit | | * LED Traffic | * Power-Off Time Delay Relay Circuit | | Lights | * Electronic Thermostat Relay Circuit | | | * AC Line Current Detector | | Analog / RF | * Pinewood Derby Finish Line Lights | | Circuits | * Pinewood Derby Finish Line Using a Computer - Scores times and | | | places. | | * Temp Indicator| * Controlling relays with logic voltages | | (Window | * ..........................................................................| | Comparator) | | | * Light Level | | | Indicator | | | (Window | | | Comparator) | | | * Mechanical | | | Wall Clock | | | Quartz | | | Synchronizer | | | * TRF AM | | | Broadcast | | | Receiver | | | * Superhet AM | | | Broadcast | | | Receiver | | | * AM Broadcast | | | Loop Antenna | | | * LED Decibel | | | Meter | | | * Whistle On - | | | Whistle Off | | | * Long Loopstick| | | AM Radio | | | Antenna | | | * Micro Power AM| | | Broadcast | | | Transmitter | | | * FM Beacon | | | Transmitter | | | (88-108 MHz) | | | * Op-Amp Basics | | | - | | | The text | | | information | | | for the basic | | | Op-Amp | | | operation, 2nd| | | order filters | | | and bandpass | | | filters was | | | obtained in | | | part from the | | | paper back | | | book "Design | | | of Active | | | Filters, With | | | Experiments" | | | by Howard M. | | | Berlin, 1977. | | | * 3 Transistor | | | descrete | | | Op_amp | | | * Active 2nd | | | Order Filters | | | * Bandpass | | | Filter (Single| | | Op-Amp) | | | * Low Power | | | Op-Amp - Audio| | | Amp (Intercom)| | | * Crystal Radio | | | Circuits | | | * Simple Op-Amp | | | Radio | | | * Low Frequency | | | Sinewave | | | Generator | | | * Low Frequency | | | Wien Bridge | | | Sinewave | | | Oscillators | | | * Simple 3 | | | Transistor | | | Audio Amp (50 | | | milliwatt) | | | * Improved 3 | | | Transistor | | | Audio Amp (80 | | | milliwatt) | | | * RC Notch | | | Filter (Twin | | | T) | | | * Analog | | | Milliamp Meter| | | Used as | | | Voltmeter | | | * hFE Transistor| | | Test Circuit | | +-------------------------------------------------------------------------------------------------+ Semiconductor Data Sheets TI Semiconductors National Semiconductors Motorola (search) (search) NTE Datasheet Archive Java Script Calculators Resistor Color Code Calculator - Graphical resistor color code calculator by Danny Goodman. Uses pulldown menus and a realistic picture of a resistor. 4,5,and 6 Band Resistor Color Code Calculator - Graphical 4,5 and 6 band resistor color code calculator including tollerance and tempco. Another Resistor Color Code Calculator - This one uses check boxes instead of pulldown menus and also calculates the equivalent value of two resistors in parallel. My own creation. Ohm's Law Calculator - Java Script to solve Ohm's Law for Voltage, Current, Resistance and Power. Enter any two unknowns and solve for the other two. Voltage Divider Calculator - Solves voltage, current, and power dissipation problems for two element resistive voltage dividers. L or C Reactance Calculator - Java Script to calculate capacitive or inductive reactance and resonant frequency. For ideal devices only, resistance not included. RC Time Calculator - Java Script to solve R and C values for given values of time or instantaneous voltages. RL Time Calculator - Java Script to solve R and L values for given values of time or instantaneous current. 555 Timer - Frequency and Time Interval Calculator - Calculates positive and negative time intervals for the 555 timer based on R and C values. Also contains descriptions and operation of each input and output of the timer and schematics for the two basic modes of operation (monostable or "one-shot" and astable or "rectangular wave oscillator"). Also contains a pictorial diagram of the timer connected as a LED flasher and a table of connections for the 556 timer (dual 555 timer). LED Series Resistor Calculator - Finds the series resistance needed for various series LED combinations and supply voltages. Several JavaScript Calculators by John Owen. - Audio op-amp filter, Op-amp circuit, Decibels, Zener Diodes and more... Air Core Inductance Calculator - Calculates number of turns and layers needed for air core inductors. Gregorian Calendar - Displays any month from Oct 1582 forward. Links to Other Hobby Electronics Sites and Useful Information Don Klipstein's LED Website - Lots of useful LED information, FAQs, and sources for the brightest and most efficient LEDs. Circuit Archive - University of Washington Circuit Archive, lots of good circuits and links. Tomi Engdahl's Electronic Info - Links to a wide variety of analog and digital circuits. Imagineering Imagineering On-Line Magazine,The Design Corner, over 100 circuits in pdf format. Links for FM Transmitter Kits, Circuits, Electronics ... Tony's Website - Free electronic circuits, R/C Gadgets, and tutorials for the hobbyist. Site in operation since 1995. Steve Walz's FTP Site - FTP Resource Site, 1000 Files in 50 Directories. Wenzel and Associates (Circuits) - Technical Library, Hobby Circuits. Samuel M. Goldwasser Homepage - Silicon Sam's Technology Resource - FAQs, Links, Troubshooting & Repair, Laser info, Circuits. Deep Cycle Battery Frequently Asked Questions Wonton Soup Recipe This recipe was copied from a local Chineese take out place. Costs $5 to buy it, and only $2 to make it. +-------------------------------------------------------------------------+ | | Electronics | | | Educational Sites | | | | | | * Making Electric | | | Circuits And | | | Electronics | | | Projects. Making | | | Electric Circuits | | | And Electronics | | | Projects. Includes | | | theory, circuits, | | | tutorials, and hobby| | | projects. | | | * PIC Microcontroller | | | Tutorial This | | | tutorial explains | | | the basic process of| | | writing programs for| | | the PICs and | | | "burning" those | | | programs to the | | | device. A | | | do-it-yourself | | | programmer can be | | | downloaded from | | | David Tait's PIC | | | archiveThe file you | | | need is | | | PIC84V05.ZIP. The | | | file contains DOS | | | software and | | | programmer schematic| | | that will work with | | | PIC16C84, PIC16F84 | | | or the newer | | | PIC16F628, but will | | | not program the full| | | 2K ROM. It's limited| | | to 1K. There is | | | newer PIC programmer| | | software for Win95/ | | | 98/xP at WinPic that| | | will program the | | | complete 2K ROM | | | (16F628) using | | | Tait's existing | | | hardware. | | | | | | * Play Hookey Basic | | | ideas about op-amps,| | | analog circuits, | | | optics, computers | | | and digital logic. | | | * Electronics | | | Tutorials A good | | | comprehensive site | | | with detailed | | | examples and book | | | recommendations. | | | * The Art of | | | Electronics | | | (Purchase the book) | | | 1125 large format | | | pages, 80 | | | component-selection | | | tables,1500 figures,| | | extensive practical | | | advice, | | | back-of-the-envelope| | | techniques, | | | exhaustive | | | 4000-entry index. | | | * LTSpice Version IV | | | LTspice IV is a | | | powerful free analog| | | and mixed signal | | | circuit simulation | | | and schematic | | | capture tool | | | offering unmatched | | | performance, speed | | | and ease of use. | | | LTspice is updated | | | with new features, | | | performance | | Commercial Electronic Sites, Kits and | enhancements and | | Projects | device models on a | | | regular basis. | | * Ramsey Electronic Kits Ramsey Electronics | * DC Circuits | | has been providing the neatest electronic | Department of | | products and kits for nearly 40 years! From | Physics, University | | AM & FM Transmitters, Hobby Kits, Video | of Guelph. | | Cameras, Time & Weather Products, Amateur | * 555 Timer Circuits -| | Radio Gear, Mini-Kits, or just Neat Stuff | All the electronics | | * Electronic Kits Store Offering a wide range | info you need to | | of educational electronic kits, robotics | know about the 555 | | kits, and electronic hobby projects. | Timer. With over 80 | | * TheLEDLight.com Luxeon LEDs, LED bulbs, | circuits. | | fixtures, flashlights, lanterns, clusters, | * All About Circuits -| | arrays, and more... | Electrical | | * Lighting Components LED Corp. LED lamps, | Engineering and | | light bulbs, clusters and lighting | Electronics | | components. | Community. | | * JDR Microcontrollers Books, Kits, Test | | | Equipment and more. | Electronic Component| | * Alltronics Electronic Kits | Suppliers | | * KitZ Electronic Kits | | | * Electronics USA - LED Digital and Binary | * 4 Star Electronics -| | Clocks, LED Timers (Up and down counting), | Obsolete Electronic | | LED flashlights, and a few other items, as | Components. | | kits or assembled. | Thousands of items, | | * Almost All Digital Electronic Kits | germanium | | * Kits-R-Us Electronic Kits | semiconductors, | | * Microchip Technology Inc. (PIC) Controllers | obsolete ICs and | | * Online Components Worldwide shipping and | memory, relays, | | over 350,000 part numbers in stock. | switches, | | * Pad2Pad.com Custom Printed Circuit Boards. | connectors, | | Free layout software and assembly service if| displays, and more. | | needed. | * Mouser Electronics | | * Express Printed Circuit Boards Download PCB | * DIGI-KEY Corporation| | software to layout your project, E-mail the | * Allied Electronics | | resulting file and receive delivery of | * Jameco | | finished circuit boards via Federal Express | * Radio Shack | | in 3 working days. | * Electronix Express -| | * C. Crane Company LED Flashlights, windup | Components and test | | radios, and other specialty items. | equipment for | | * This link space is available | schools, colleges | | * This link space is available | and industry. Very | | | nice site. | | Newsgroups | * Bill's Surplus Parts| | | For Sale- Resistors,| | * sci.electronics.basics | capacitors, | | * sci.electronics.components | semiconductors and a| | * sci.electronics.design | few other items. I | | * sci.electronics.repair | don't have a large | | | inventory, just more| | * ............................................| than I need. | +-------------------------------------------------------------------------+ Go to top For help with circuits not listed here, please post a message with details to one of the electronic newsgroups, either sci.electronics.basics or sci.electronics.design Many readers of those groups will offer ideas and a few specifics at no charge. For help with specific circuits on this site, or some minor modification, please email the details and I will try to resolve it. I can also build completed circuits shown here for a small fee depending on time involved. Please do not attach large files over 200K to email messages. I still use a dial-up connection with minimal bandwidth, and cannot download large files over 200KB. ++ ++ web counter web counter Copyright 1996 - 2016 (Bill Bowden) ---------------------------------------------------------------------