Single MOC3011 optocoupler triggers two SCRs.
Student-Hobbyist Electronics Projects Tutorials
by Lewis Loflin
Follow @Lewis90068157
Introduction - The purpose of these pages is to introduce the student and hobbyist to electronics projects.
I've been a part-time adjunct professor at a local community college teaching electricity and electronics.
Today I do this for the shear love of electronics.
I have 50 years experience in electronics, from vacuum tubes to modern solid state and industrial controls. I tend to teach from a general science viewpoint.
This site has been up for about 20 years and covers a number of subjects broadly how to use the Arduino microcontroller and semiconductor components such as transistors, MOSFETs Zener diodes, op-amps, etc.
These are presented as information only - you assume all risk. Most voltages are under 24-volts. Read this safety warning.
See my You Tube Videos page lists the over 206 videos on My YouTube Channel.
Here are quick navigation to the many parts I cover. These build on each other.
IR2110 High Voltage H-Bridge Driver
Click image for larger view.
H-Bridge Motor Controls
An H-Bridge, in general, is a 4-switch (often a type of transistor) circuit used to control the direction of a permanent magnet DC motor. Through the use of a microcontroller, speed and direction can be controlled.
- Build H-Bridge Motor Control with Power MOSFETS Updated
- Arduino Controlled IR2110 Based H-Bridge HV Motor Control
- Arduino Constant Current H-Bridge Motor Control
- All NPN Transistor H-Bridge Motor Control
- Arduino Constant Current H-Bridge Motor Control
- Build a Bipolar Transistor H-Bridge Motor Control
- Tri-State H-Bridge using CD4093B CMOS Circuit
- Simplified CMOS-MOSFET H-Bridge Circuit
- TA8050P H-Bridge Motor Control
- IGBT Based High Voltage H-Bridge DC Motor Control
- High Voltage IGBT H-Bridge Circuit Video
- More circuits using mixed transistors.
- Tri-State H-Bridge Uses Optocoupler Voltage Isolation
- Driving Darlington Transistors with Optocouplers
- H-Bridge Schematic with MOSFET Outputs
- H-Bridge Schematic with Darlington-MOSFET Transistor Outputs
- H-Bridge schematic with Darlington-IGBT Transistor Outputs
- From Basic Digital Circuits to H-Bridge Motor Controls
Videos:
Arduino CCS H-Bridge with Large DC Motor
Program Code Arduino CCS H-Bridge Motor Control
Transistors used in these Projects
I present many transistor tutorials, including testing and comparing devices.
There are broadly two transistor types: MOSFET and bipolar. There is a third type known as an IGBT, a hybrid of MOSFET and bipolar. Another subtype of the bipolar transistor is the Darlington, used for high power gain.
There are important differences besides varying voltage and current ratings. Their operation differs: a MOSFET is voltage controlled; a bipolar transistor is current controlled.
An IGBT is voltage-controlled but acts as a bipolar transistor. We explore these circuits in detail.
- MOSFET transistor and IGBT transistor tutorials:
- Test Power MOSFET Transistors, IGBTs Results
- N-Channel Power MOSFET Switching Tutorial
- P-Channel Power MOSFET Switch Tutorial
- More Power MOSFET H-Bridge Circuit Examples
- High Voltage MOSFET Switching Circuits
- Insulated Gate Bipolar Transistor IGBT Circuits
- Issues on Connecting MOSFETs in Parallel
- Bipolar transistors:
- Basic Bipolar Transistor Driver Circuits
- Build a Bipolar Transistor H-Bridge Motor Control
- ULN2003A Darlington Transistor Array with Circuit Examples
- Tutorial Using TIP120 and TIP125 Power Darlington Transistors
- Driving 2N3055-MJ2955 Power Transistors with Darlington Transistors
- Understanding Bipolar Transistor Switches
- Design 10-Amp 2N3055 Based Power Switch
- Common Collector Opto-Isolated Bipolar Transistor Switches
- Compare 2N3055 MJE10005 Transistor Power Switches
Transistor Driver Circuits
Broadly using low-voltage digital controls often can't directly operate high voltage and high power transistor circuits. So we use various forms of driver circuits.
Small transistors can drive larger transistors. Opto-couplers can provide voltage isolation and can drive other transistors. We have circuits such as the TC4420 integrated circuits that can do both.
There is a separate section on optocoupler circuits below.
- MOSFET-Transistor Drivers with TC4420 and TC4429, IGBTs, etc.
- Introduction TC4420-TC4429 MOSFET Drivers
- Use TC4420 MOSFET Driver for Simple H-Bridge Circuit
- TC4420 MOSFET Driver Various Circuits
- TC4420 MOSFET Driver Replacement Circuits
- Optical Isolation of H-Bridge Motor Controls
- Opto-Isolated Transistor Drivers for Micro-Controllers
- Basic Bipolar Transistor Driver Circuits
- Test Power MOSFET Transistors, IGBTs Results, Observations
- High current TTL MOSFET Driver Circuit
- Insulated Gate Bipolar Transistor IGBT Circuits
- Optocouplers for TTL-CMOS Logic Level Shifting
- Insulated Gate Bipolar Transistor IGBT Circuits
- VOM1271 Photovoltaic MOSFET Driver Circuits
- Bidirectional Solid State Relay Circuits
- Simple Solid State Relay for Low Power LED 120V Lamps
- Build High Power MOSFET Directional Switch Relay
Test Reuse Surplus Personal PC Power Supplies
Power Supplies
Power supplies come in three types for the hobbyist: build, buy, or salvage. I address all of this.
- Test Reuse Surplus PC Power Supplies
- AC Power Supply Rectification
- Build an Adjustable 0-34 volt power supply with the LM317
- Transistor-Zener Diode Regulator Circuits
- Tips for the LM78XX Series Voltage Regulators
- Bi-Polar Power Supplies
- Connecting Series-Parallel Batteries
- Basic Power Transformers
- Connecting Transformers in Series-Parallel
- Voltage Buck-Boost Transformer Connections Tutorial
- Connecting Industrial Control Transformers Examples
Safety issues:
- Warning About Electrical Shock and How to Prevent It
- Load Lamp Safely Allows Safer Electronic Testing
- Build Autotransformer-Variac AC and DC Power Supply
- Build Autotransformer-Variac AC and DC Power Supply YouTube
Switching Power Supplies
- Operation switching power supplies and transformer connection tutorials:
- Generating High Voltage with an Inductor
- Arduino Buck Switching Voltage Regulator Demo Only
- Switching Regular Configuration Review
- LM2575 Simple Switching Voltage Regulators
- Voltage Buck-Boost Transformer Connections Tutorial
- Test Reuse Surplus Personal PC Power Supplies
Opto-Coupler SCR and Triac Circuits
SCRs and Triacs are used to control AC and DC power systems. With a microcontroller such as Arduino using a zero-crossing can control AC power to control light levels, AC motor speed, and resistive heating elements..
- Basic Triacs and SCRs
- Solid State AC Relays with Triacs
- Diac Waveform Generator, Trigger Circuits
- SIDAC Operation and Trigger Circuits
- Light Activated Silicon Controlled Rectifier (LASCR)
- Light Activated SCR Based Optocouplers Circuit Examples
- Comparing Photo Triac, Photo SCR Opto-Couplers
- Silicon Controlled Rectifier Review and Circuits
- Silicon Controlled Rectifiers Connected as Power Triacs
- Simple Triac-SCR Test Lab for You Tube
- AC Zero Crossing Detectors for Arduino
- Zero-Crossing Detectors Circuits
- Hardware Interrupts Demo and Tutorial for Arduino
- In Depth Look at AC Power Control with Arduino
- Arduino AC Power Control Using Interrupts
Click here. Optocoupler list continues below.
A zero-crossing detector produces a pulse at the beginning of every half-cycle in an AC sine wave. For 60Hz, this is 120 pulses per second. Then we use a microcontroller to phase control the power.
- Arduino AC Power Control Using Interrupts
- Hardware Interrupts Demo and Tutorial for Arduino
- In Depth Look at AC Power Control with Arduino
- AC Zero Crossing Detectors for Arduino
- Zero-Crossing Detectors Circuits
- LM555-NE555 One-Shot Multivibrator AC Power Control
My experimental flashtube test setup.
Xenon photoflash tubes create a bright flash in cameras, strobe lights, etc., in conjunction with SCR, SIDAC, and DIAC circuits.
Caution: xenon flash tubes are high-voltage devices, often 300V DC.
- Understanding Xenon Flashtubes and Circuits
- Unijunction Transistor SCR Photo Flash Control Circuit
- SIDAC Controlled Flashtube and Pulse Circuits YouTube
- Simple 12-14 Volt DC to High Voltage AC Inverter for Flashtubes
- Neon (NE-2) Circuits You Can Build
- Simple DIAC Based Relaxation Oscillator Pulse Generator
- Diac Waveform Generator, Trigger Circuits
- New: How to use SIDACs and Their Operation
- SIDAC Operation and Trigger Circuits
- Understanding Unijunction Transistors Theory Operation
LM317 power constant current control.
Constant Current or Current Limiter Circuits
The TL431A, The LM317, and LM334 are power and inexpensive current regulators used for lighting LEDs, controlling battery charger current, etc.
The LM317 and related parts are used in low-voltage DC power supplies.
New January 2024.
- Using TL431A Li-Ion Battery Charger Tutorials
- TL431 Over-Voltage, Under-Voltage Detector Circuits
- TL431A Constant Current Source Working Circuits Demo
- Power TL431 Constant Current Source Circuits
- TL431, LM317 Battery Charger Circuits Schematics
For YouTube videos on this section see My You-Tube Electronics Videos
- Experiments with TL431 Shunt Regulator
- TL431 Precision Current Regulator Circuits
- TL431 Based Current Limiter Constant Current Source Circuits
- TL431 Shunt Regulator Circuits
- TL431 Sink Mode Constant Current Circuits
- Battery Charger related:
- Arduino Solar Panel Battery Charge Controller Switching Circuit
- TL431A Lithium-Ion Cell Charging Circuits
- Charging Multi-Cell Lithium-Ion Battery Packs
- TL431 Battery Charger Voltage Detector Circuits Schematics
- TL431 Battery Charger Voltage Detector Circuits Schematics
Video: Arduino Battery Charger uses CCS and TL431 Comparators
- Arduino Constant Current H-Bridge Motor Control
- Constant Current Source Theory Testing
- Arduino Controlled Power Constant Current Source
- Constant Current Circuits with the LM334
- LM334 CCS Circuits with Thermistors, Photocells
- LM317 High Power Constant Current Source Circuit
- LM317 Constant Current Source Circuits
- LM317 Adjustable Voltage Source Current Boost
- LM317 Constant Current Source for Lighting LEDs
- 3 Amp LM741 Op-Amp Constant Current Source
- Current Limiter Allows Safe Testing of Zener Diodes, LEDs
- Photo Detector Devices:
- LM334 CCS Circuits with Thermistors, Photocells
- Photodiode Circuits Operation and Uses
- Photodiode Op-Amp Circuits Tutorial
- Photo Voltaic Tutorial MOSFET Output Solid State Relays
- YouTube:
- Photodiodes and How they Work
- Photodiode Op-Amp Circuits
- Using Photovoltaic MOSFET Drivers
SN74HC14 based square wave generator with differentiator circuit.
- Digital Circuits:
- Simple Schmitt Trigger SN74HC14 Square Wave Generator
- Introduction to RC Differentiator Circuits and Uses
- SN74HC14 Square Wave Generator uses SN7476 JK Flip-Flop
- Three Output Digital Pulse Generator
- Basic TTL Tri-State Buffer Circuit Examples
- Tutorial NOR Gate SR Latch Circuits
- Tutorial NAND Gate SR Latch Circuit
- Tutorial OR-NOR Circuits Monostable Multivibrator
- Tutorial of XOR and XNOR Logic Gates
- LM555-NE555 One-Shot Multivibrator AC Power Control
- Basic TTL Tri-State Buffer Circuit Examples
- Astable CD4047 High Voltage Power Supply
- CD4047 Monostable Multivibrator Circuit
- Simple 2 Transistor LED Flasher Circuit
- Neon (NE-2) Circuits You Can Build
- Build 12AV6 Vacuum Tube AM Radio
- Coils for Highly Selective Crystal Radio
- You Tube Videos
- 12AV6 Vacuum Tube Radio with LM386 Power Amplifier
- Grid-Leak Detector Low Voltage Vacuum Tube Radio
- Astable CD4047 High Voltage Power Supply
- CD4047 Monostable Multivibrator Circuit
- LM2575 Simple Switching Voltage Regulators
- Simple 2 Transistor LED Flasher Circuit
- Generating High Voltage with an Inductor
Arduino Microcontroller Projects presents many tested projects and examples for Arduino. The emphasis is hardware control which suggests one has an electronics background. Having a background in digital logic and binary code is also helpful. The projects will explain this as needed.
What differs here is I avoid the use of Arduino-only code and code libraries to port the basic code algorithm to Python, PICAXE basic, or Microchip PIC C.
See Arduino Projects Hobby Projects Tutorials.
- Arduino Reads Temperature Sensor Displays Temperature on LCD Display
- Arduino with MCP4725 12-bit Digital-to-Analog Converter Demo
- Simple 3-Wire MAX6675 Thermocouple ADC Arduino Interface
- Programming ADS1115 4-Channel I2C ADC with Arduino
- Arduino uses ADS1115 with TMP37 Heat Sensor to Measure Temperature
- Connect Arduino to I2C Liquid Crystal Display
- Videos
- Arduino with ADS1115 4-Channel 16-bit Analog-to-Digital Converter
- Arduino with MCP4725 12-Bit DAC
- Arduino PWM to Analog Conversion
- Arduino Analog Digital Conversion Voltmeter
- Rotary Encoder Using Arduino Hardware Interrupts
- Better Arduino Rotary Encoder Sensor
- Arduino DC-AC Power Inverter
- Arduino Stepper Motor Drive Coil Winder
- TB6600 Stepper Motor Driver with Arduino
- Arduino IF Statement Code Examples
- Arduino Projects Revisited Revised
- Arduino IR2110 Based H-Bridge HV Motor Control
- Arduino Measures Constant Current Source
- Arduino Controlled Constant Current Source
- Microcontroller controlled CCS New:
- Constant Current Source Theory Testing YouTube
- Constant Current Source Multimeter Trouble Shooting YouTube
- Arduino Controlled Constant Current Source YouTube
Hall Effect sensor are used in many modern application in the gas and electric vehicles, motors, and industrial controls. They are fun to use and knowledge of this device is essential in modern electronics.
All Hall sensors have an analog (ratiometric) voltage proportional to magnetic flux level. When combined with comparator circuits can form a Hall switch used in digital and computer control applications.
- Hall Effect Magnetic Switches and Sensors
- Using Ratiometric Hall Effect Sensors
- How Hall Effect Sensors Detect Ferrous Metals
- YouTube videos:
- Basic Hall Effect Sensors YouTube
- Hall Effect Sensor Circuits YouTube
- More sensor non Hall Effect
- Analog Thermocouple Operation, Amplifier
- Thermocouple Digital Interface
The Schmitt triggers used here are based on an analog comparator. These can use operational amplifiers (op-amps) such as the LM358 or LM741.
Or one can use the LM311 comparator or LM339 quad comparator. They have open collector outputs unlike the LM358 or LM741 op-amps.
A comparator "compares" two analog voltages and turns on-off based on their voltage levels.
Often considered "digital" at this point, we have, in reality, a one-bit analog-to-digital converter.
- Comparator Circuits:
- Comparator Theory Circuits Tutorial
- Comparator Hysteresis and Schmitt Triggers
- Voltage Comparator Information And Circuits
- Looking at Window Comparator Circuits
- Analog Battery Charger Uses Comparators
Microchip PIC Projects PIC18F2550, PIC16F628A, PIC12F683
Major updates 7-30-2024.
The website has been here almost 20 years and the entire Microchip PIC section is being updated. This is due to obsolete parts used in the projects, plus the addition of using PIC Basic Pro. I'll use the student edition combined with assembly routines.
Also included in that section is assembly language projects for the PIC PIC16F628A and PIC12F683. While cheap and versatile controllers there's a steep learning curve in using assembly.
Introduction to PIC12F683 Programming
- Main Pages for PIC:
- PIC18F2550 Main Page
- PIC16F628A Main Page
Start here: Introduction PIC12F683 Programming Circuits Tutorial
I own and have used the K150 programmer and the Velleman K8048 PIC Development Board.
The Velleman K8048 PIC Development Board is available from Amazon. It requires assembly (soldering) and uses a standard PC serial port (or USB adaptor), plus a 15-volt power supply is not included. It will program 8, 16, 18, and 28-pin PIC controllers.
Need help or have questions email me at lewis@bvu.net.
- Microchip PIC related videos:
- Using Velleman K8048 PIC Development Board
- How to Use K150 PIC Programmer
The PICAXE Microcontroller I use is the medium-range PICAXE-18M2. While built hardware-wise on a Microchip PIC controller, it has an easy-to-learn built-in proprietary basic. PICAXE is for students rather than serious, commercial applications.
I will no longer use PICAXE but Microchip PIC controllers.
- PICAXE Projects Reference Example Projects
- PICAXE Operates H-Bridge Motor Controller
- PICAXE Microcontroller Controls Motor Speed - Direction
Raspberry Pi to Arduino interface.
The Raspberry Pi can be programmed in Python like a Linux PC, or in C. I prefer C.
The operating system is often Debian Linux, which is also used for a Linux PC. The Openbox Desktop is used in both.
- Raspberry Pi Openbox Desktop 2019
- Setting up Openbox for Raspberry Pi
- Sensors using I2C serial connection.
- Interface I2C LCD to Raspberry Pi in C
- ADS1115 4-Channel ADC Uses I2C with Raspberry Pi
- MCP4725 12-Bit DAC Interface to Raspberry Pi
Because most computers today don't have hardware printer ports the following sections are for reference. Programming can overlap Raspberry Pi.
Light Fast Linux Desktops with Openbox, JWM. Still useful for PCs and Raspberry Pi.
The following is useful for C programming examples using electronic hardware.
- Build Serial HD44780 LCD Display Connect to Parallel Port
- Hardware Review Connecting PC Parallel Ports
- Operation TB6600 Stepper Controller with PC Parallel Port
- Build or Buy Parallel Port Breakout Board?
- Exploring Digital Computer Electronics
- Add MPG123 Terminal Music Player to Raspberry Pi, Linux
- Basics of Alsamixer Audio Control for Linux
- Using FEH Wallpaper Setter Under Linux
- YouTube:
- Reuse PC ATX Power Supply YouTube
- More on Reusing PC Power Supplies YouTube
- Using the powerful Rox-Filer system in Linux
- Use FEH under Linux for a Wallpaper Setter
Python Programming PC Printer Port Hardware Interfacing. Uses Python and obsolete Linux distribution, info only.
Ebay search "Electronics Component Basic Kit". Many component starter kits from $16 to $25.
- Review Ohm's Law for Trouble-Shooting CCS Circuits
- Theory and Operation of Capacitors
- Basic Magnetics and Analog Volt and Amp Meters (pdf)
- Basic DC and Ohms Law (pdf)
- Basic Light Emitting Diodes (pdf)
- Astable CD4047 High Voltage Power Supply
- CD4047 Monostable Multivibrator Circuit
- Geiger Counter and Radioactivity
- Introduction to Geiger-Mueller Counters and Electronics
Popular Webpages & Corresponding Videos
- Hall Effect Magnetic Switches and Sensors
- Basic Hall Effect Sensors Video
- Opto-Isolated Transistor Drivers for Micro-Controllers
- Opto-Couplers Theory and Circuits Video
- H-Bridge Motor Control with Power MOSFETS Updated
- Build Power MOSFET H-Bridge for Arduino YouTube Video
- LM317 High Power Constant Current Source Circuit
- Adjustable LM317 High Power Current Source Video
- ULN2003A Darlington Transistor Array with Circuit Examples
- ULN2003A Transistor Array with Arduino Video
- Constant Current Circuits with the LM334, LM317
- Constant Current Source Tutorial YouTube Video
- N-Channel Power MOSFET Switching Tutorial
- P-Channel Power MOSFET Switch Tutorial
- Using Power MOSFETs with Arduino YouTube Video
- Zero-Crossing Detectors Circuits and Applications
- Zero-Crossing Circuits for AC Power Control Video
- In Depth Look at AC Power Control with Arduino
- Micro-controller AC Power Control Using Interrupts
- YouTube Video for Arduino AC Power Control Video
- All NPN Transistor H-Bridge Motor Control
- All NPN Transistor H-Bridge Motor Control YouTube
- Videos:
- Why Your MOSFET Transistors Get Hot Video
- H-Bridge Driving Large Motor Video
- Issues on Connecting MOSFETs in Parallel Video
- Simple Circuits for Testing MOSFET Transistors Video
- Off Site:
- Bristolblog an Alternative News Skeptic Site
- Web Master
- Tri-Cities VA-TN
- General Science
- US Constitution
- Christianity 101
- Religious Themes
Misc. opto circuits.
- Tri-State H-Bridge Uses Optocoupler Voltage Isolation
- Current Limiter Circuits for Opto-Coupler Input LEDs
- Optocouplers for TTL-CMOS Logic Level Shifting
- MOSFET DC Relays Using Photovoltaic drivers
- H11L1, 6N137A, FED8183, TLP2662 Digital Output Optocouplers
- Optocoupler Input Circuits for PLC
- Solid state relays with optocouplers:
- Photo Voltaic Tutorial MOSFET Output Solid State Relays
- Connecting Crydom MOSFET Solid State Relays
- MOSFET DC Relays Using Photovoltaic drivers
- Exploring Solid State Relays and Control Circuits
- Bidirectional Solid State Relay Circuits
- Build High Power MOSFET Bidirectional Switch Relay
- VOM1271 Photovoltaic MOSFET Driver Circuits
- Light Activated Silicon Controlled Rectifier (LASCR)
- Simple Solid State Relay for Low Power LED 120V Lamps
- Comparing Photo Triac, Photo SCR Opto-Couplers
- Light Activated SCR Based Optocouplers Circuit Examples
- Build High Power MOSFET Bidirectional Switch Relay
Web site Copyright Lewis Loflin, All rights reserved.
If using this material on another site, please provide a link back to my site.