High Resistance Meter

I don't remember if this circuit worked properly. But a few were made and i might not have shown the modifications that were done to make it work. This was meant to be a portable, low cost, insulation tester for an electrician. If you try it out and debug it it may work well.

A negative voltage is derived by shifting gnd with two diodes, i feel this did not work very well. Two pins of CD4028 pins are also used to boost the reference to get two extra ranges as 4051 has a 100E on resistance.

The 555 clock makes 4029 counter count. But the clock can be clamped to gnd by a TL062 window comparator. The clock is frozen when the input value to comparator pin 5-2 is within a lower limit and upper limit "window" pin 3-6.

The 4029 counter BCD is decoded to decimal by 4028 which drives the LEDs, keep LED drive within 3mA or chip will be loaded. Use high efficiency extra-bright LEDs.

The 4029 BCD also controls a shunt resistor array with CMOS switches 4051. The voltage across shunt is a sample of leakage current. This is compared in the window comparator to freeze the Clock and LED display to give a reading of the leakage current or Insulation Resistance.

Femto OS - RTOS for Atmel AVR ATmega

The Femto OS is a very concise portable real time - preemptive operating system (RTOS) for embedded microcontrollers with minimal ram and flash, say 2KB .. 16KB flash and 128 .. 1024 bytes ram. The main target is the Atmel AVR architecture, such as the ATtiny or smaller ATmega series.

Femto OS - RTOS for Atmel AVR ATmega

Femto OS is specially made for small embedded devices. For example, the 'Smallest application' is the application called 'Bare' compiled for the ATmega8. It solely runs a 16 bit led counter on the idle task hook. It consumes 258 bytes of flash and 10 bytes of ram.

- Ruud Vlaming

Read More -

• Femto OSA tiny multitasking operating system for microcontrollers
• AVR Studio 4 is the Integrated Development Environment (IDE)

Ham Shack of W5JGV – Ralph

My Start as a Ham - Ralph's Story - "I suppose my interest in things electrical began when at a very young age I poked a metal hairpin into an electrical outlet. To this day, I vividly remember the amazing flash and bang that resulted! Of course, I wanted to know why that happened. It was a few years more before I learned to read, and found out about electricity."

Ham Shack of W5JGV - Ralph

Then ralph has many projects with educative information. A RF Ammeter the Easy Way. A 400 Watt 60 Hertz Power Inverter. These are interesting to study.



Experimental KW HV Switching Power Supply

The design of switching supplies is a bit more involved than traditional "big iron" transformer power supplies. When taken step-by-step, however, it is quite possible for an amateur to design and build a working high power switching power supply. This article describes a high power, high voltage switch mode power supply designed to operate a KW level RF power amplifier.

Home brew Litz Wire

The Litz wire was fashioned by taking two parallel strands of #18 AWG wire about 115 feet long and twisting them together in a clockwise direction with an electric drill until the twisted wires had about two turns per inch. The twisted wire was then cut into four equal length and laid side by side.

delabs Notes

All Mains Inlet Sockets should be Shuttered, so that such a thing does not happen again to any child again. Another Law, No Mains Socket should be less that 5 feet above the ground level.

EMerge Alliance - Safe Low-voltage Power

Then we should all move to a 24V home voltage standard, Read more at my Tech blog..

Embedded 8051 TCP-IP WebServer

Web51 is a complex project of connecting an Intel x51 compatible processor to a Realtek RTL8019AS network controller. The result is a very low-cost Ethernet interface. Since a well-known x51 architecture is used, even small and medium-scale businesses can now network their devices.

Project is free. Almost all source codes are available.

Web51 - Project start page



Charon module

Twisted Pair Ethernet 10 Mbit 802.3,Serial TTL level compatible line RS232 (RxD, TxD, RTS, CTS), 32 kB RAM, 64 kB FLASH, 2kB EEPROM.

Murray's Website is missing so here are the related resources.

 

ET have produced a remarkable board in the WEB51. It is based on the popular Atmel AT89C51RD2 microcontroller, and features the RealTek RTL8019AS full-duplex ethernet controller chip.

You get a huge 64K In-System-Programmable FLASH memory for code and web content, backed up by up to a further 4 optional, I2C addressable EEPROM memory chips.

The ET-WEB51 TCP/IP Ethernet Web Control Board comes preloaded with TCP/IP software that allows you to control outputs, sense inputs and write text to an LCD. All this across the Internet via a standard browser.

"From controlling appliances on your home network, to monitoring industrial processes on the other side of the Earth, the ET-WEB51 can do it all."

Embedded 8051 TCP-IP WebServer

littleBits – Snip Snap and Build Electronics

littleBits is a growing library of pre-assembled circuit boards that snap together with tiny magnets!

littleBits - Snip Snap and Build Electronics

littleBits are simple, intuitive, space-sensitive blocks that make prototyping with sophisticated electronics a matter of snapping small magnets together. Each bit has a simple, unique function (light, sound, sensors, buttons, thresholds, pulse, motors, etc), and modules snap to make larger circuits.

My Notes -

A kid started with "Meccano Set" in the early days. Then there came "The LEGO" now we have littleBits doing it for DIY Electronics Learning. Shown below is a Meccano Kit.

mbed - Rapid uC Prototyping

The mbed Microcontroller is made for prototyping, and comes in a 40-pin 0.1" pitch DIP form-factor so it's ideal for experimenting on breadboard, stripboard and PCBs. It is a uC ScratchPad for trying out new ideas.

mbed - Rapid uC Prototyping



The mbed Compiler lets you write programs in C++, and then compile and download them to run on the mbed Microcontroller. The mbed Compiler is a Web-App in the Cloud, you don't have to install or setup anything to ignite your first mbed project idea. Any OS, Any Where, your software is online and ready to use. You will need a computer or netbook with a Browser.

Pinguino - Arduino-compatible for PIC

Pinguino is an Arduino-compatible open source hardware electronics prototyping platform. It supports different 8- and 32-bit microcontrollers, all with built-in USB module

New library : I2C 16-bit I/O expander #Pinguino can now drive Microchip MCP23O17 / MCP23S17 16-bit input/output port expanders with i2c interface, interrupt output and cascadable for up to 8 devices on one bus.

Pinguino - Arduino-compatible for PIC

Pinguino Software is an Integrated Development Environement (IDE) which gives everyone the ability to write, compile and upload programs on a Pinguino board.

Pinguino comes with a USB Bootloader. This small program running inside the microcontroller is responsible for transferring your application from your PC to the microcontroller memory and handing over the control to this program afterwards.

Optical Sensor for Viscous Liquid

This was built for a Varnish Impregnation Unit. It could be Epoxy or some liquid used in Coil-Capacitor Vacuum Impregnation Process. This was fixed behind a Glass Window, when the liquid reaches this level, the circuit senses it and works like a limit detector. Hence the name Optical Proximity Switch. It is fairy simple in design. It worked after a few trials.

This was a custom design. We always should cost custom designs more, there is more time and materials used up. Only when some quantities are made, you can make it break even. Costing should also involve a R&D component, this is needed to build the in-house lab. Many good firms today, owe their present performance to the research effort and investment done by their predecessors.

InfraRed Detector for Proximity Switch « delabs Schematics

Amicus an Arduino Like for Microchip PIC

Amicus is a multifunction development system inspired by the popular Arduino board, however, the Amicus board uses a Microchip PIC microcontroller instead of an Atmel AVRtm type.

Amicus an Arduino Like for Microchip PIC



Extension boards add functionality to the Amicus, these boards are known as shields. A shield is a PCB that fits over the Amicus board and provides extra functionality, such as Ethernet, Motor control, LCD, Smartcard, GPS, GSM etc…

Amicus is supported by an integrated development environment (AMICUS IDE).

• Proton Basic source code editor - with colour syntax highlighter
• Compiler - Full version of Proton Basic for the PIC Microcontroller with full integration to MPLAB for debugging, if required.
• Programmer - automated programming of the Amicus Board - no external programmer required.

Stereo Audio Music Players

40 Watts Hi-Fi Music System - Stereo Music player with Tuner, 1986, LED VU meter and Analog VU meter.



This was done as repairing home electronics was my hobby in school days, I learnt by building Amplifiers based only on transistors from the Old Philips Circuits and Books. The above one is TDA2020 20 Watts Per Channel, with LED input level meter and moving-coil output meters.

Home Made Circuits

It would have a 5 pin din input and RCA speaker output, input for phono, tape, etc. The Speakers had a woofer, tweeter and midrange with passive crossover network.



Stereo Adapter for Portable Music Player

Low Cost Stereo Adapter 20 Watts for Portable Music Player 1984, Bass Treble and Presence.



This was a TB810 based 10+10 Watts Stereo Amplifier with LM381 or 2 Preamplifier, The portable player docks in a wooden cabinet. There was no IR, Wi-Fi or Bluetooth in those days, so the device would interface with amp thru a stereo ear-phone socket-jack system with a shielded cable. Bass, treble and Presence as per an old phillps audio amp book.

PIC Project by Myke Predko

"The application itself consists of the 16F84 PICMicro (with power, reset and clocking 'core') with two LEDs and a button. One of the LEDs is lit by the PICMicro while the other is lit when the button is pressed. "
PIC Project by Myke Predko
 


The Experience he Gained -

"There is one point to make about the layout that you should always keep in mind when developing a circuit with a microcontroller or other programmable device; you should always design the circuit in such a way that the chip can be pulled easily. This means that there should be space at either end for prying the chip up out of its socket or, as I like to do, slide a small screwdriver underneath the PICMicro and "pop" it up simply by twisting it. I know a lot of people that end up cursing themselves because they've forgotten to remember this basic operation"


The Experience of the remote Hobbyist is very important for a Kit Maker or Gadget Maker. We tend to feel .."everybody thinks like me". Each person has his own faculties, tools and experience. Most importantly - the method of teaching which has to adapt to each student. Hence it is important to have a spread of different things and methods, for a enthusiast to choose from. - delabs

The Micro Stop - RS232 and microcontroller schematics and C code, a lot is free! RS232 DVM-001 Voltage Input Board in Kit Form or Fully Assembled and Tested

123 PIC MCU Experiments for the Evil Genius by Myke Predko

Supercap and White LED and Energy Harvesters

This is a educative and simple example to help learn about supercaps and white LED. It will also help you understand component behavior. If you are learning electronics, try this one out.

The goldcap-Dynamo Lamp idea is a DIY Tutorial by Kainka on Electrical Energy Harvesting. What may be this EH Thing ?



Energy harvesting (also known as power harvesting or energy scavenging) is the process by which energy is derived from external sources (e.g., solar power, thermal energy, wind energy, salinity gradients, and kinetic energy), captured, and stored for small, wireless autonomous devices, like those used in wearable electronics and wireless sensor networks. - EH at Wikipedia
 
Then the Cycle Dynamo may not be the ideal choice for furthering this research. The reason being, this is quite a powerful source of energy, especially when going downhill!

Electric Double Layer Capacitor - EDLC

We need a more fussy source of Electricity. Like the waves of the sea, that could splash onto Large plates of Springy Beryllium Copper Cantilevers, which moves an Array of Magnets in coils (Reverse of Solenoids). This gives Random Spurts of High Energy Pulses which have to be Harvested.

Piezoelectric Energy Harvester – Mide Technology

That is for you to dare and do ........ Now let me give some things you can read, before you start this epic Adventure...

Electric double layer capacitor an eFlywheel

Now Move ! There is so much Abundant Energy to be Harvested. You can Even Setup a Roadside Electric Trike Recharging Station. - Gomier Electric Tricycle

We need more contests, An LED Lighting Contest and a Sponsored Elekrik Vehicle (Non-Car) Super-Contest.

LED Light Bulbs in LED Lighting

LED Lighting is not another Florescent Lamp or CFL, it has a Luminous future. Some Manufacturers have hurried a bit and made some below average quality products. We can say many are on Beta Stage. Let us not spoil its reputation or market, due to these guys.
Keep improving, there is no other alternative. Edison lamps i like, but are power hungry. CFL's are fragile and fail often. LED is important, we need to make it happen. Every designer and manufacturer has to be reliability concious and be very serous about it. If we cannot do a good job, let us not do it at all.
LED Lamp with Voltage Boost - Here the circuit is boosting the voltage, The current feedback is used to maintain brightness as battery weakens.- ELM - White LED Head Lamp
Illuminating LED Page of Garry Petrie - This page has all the basics you need to know, read this page well to prime your DIY Bench into a LED Lamp Factory. - The Perfect Light
Cant Make 'Em then you Gotta Buy 'Em. - Try this - Control your moods with colors from a LED Bulb. Ideal for Meeting rooms and Brainstorming sessions. - delabs
Naxos PAR-20 Color LED Light Bulb 8-Watt
Featuring three Luxeon K2 LEDs, this high-power RGB LED PAR-20 bulb (E26 'standard' socket) can be controlled with a remote controller!

• 15 different color modes
• Neutral white, Warm white
• Dimming control, Flash mode
• Strobe mode, Fade mode, Smooth mode

Quick look at Some stuff i use – made

Its a Paper Mache Ball on Ferrite. The Base is a DIN Bezel. Many parts are Electromechanical and Electronic Metal Hardware. Plastic Caps and Reed Relays too.


Thanks Weller for making the Best Soldering Iron

Prototyping to prove a Design Concept

Before simulation in EDA tools. First stage of concept proof or design tweaks were made on BreadBoard, Stripboard or General Purpose PCB.

Even now it is used after simulation or directly. Many RF and Power electronics designs may have to be verified and modified on Pilot Production. Digital Designs and Software/Firmware checks don't need hardware prototypes, but need a proven framework to test it on.



Hobby and Education learning must use breadboards alongside simulation, even though educational eda tools are used. Breadboard connects us with the reality, the way it is. Then you will even simulate better. Robotics and Developing Mechatronics Solutions may need prototyping and modifications many times over.

Soldering and Shiny joints are everything in electronics. One dry solder, a cut track, a solder bridge or splatter near the IC can make a card malfunction.

Thin copper tracks taking high currents, HV and LV circuit isolation, Ground loops, RF Antenna Effect, Ground Plane and Guard rings are just some things to know on Component to Component Connections, that make a huge difference.

In Design Notes of Soldermans Basic Electronics you will find my learning notes in electronics. How this learning happened ?

I had setup my Hobby Science/Electronics Lab when i was in School, In college i was helping others learn practical electronics. I worked in Product Design and Engineering Departments when i was Employed. During this time my Electronics Lab was a Free Training Center, sponsored by my own pay. Then i started my manufacturing firm.

delabs Technologies

More reading  - Luciani.org Breadboard Hints - John Luciani explains how to prototype a circuit to try out a concept.

Gabotronics – Oscilloscopes and Embedded Kits

Designs and manufactures embedded systems. Specialized in 8-32 bits microcontroller projects, instrumentation and data acquisition, PCB Layout, custom electronic designs and engineering consultation. Based in Palmetto, FL.

Gabotronics - Oscilloscopes and Embedded Kits

COMA+ The All in One Instrument, will enhance the original specifications, like using a TFT display and using a few external ICs to simplify the design, like the ICL7135 multimeter IC, and a DDS to generate the waveforms, probably the AD9833.

Is it a Calculator, Oscilloscope, Multimeter, Analyzer….; No it is The Coma+ .

Some Features

• 2 Channel, 8bit 16MSPS Oscilloscope
• FFT on acquired data
• 8 Channel Logic Analyzer
• Arbitrary Signal Generator
• Frequency Generator
• Multimeter:
• Volt Meter, 1 M ohm Input impedance

Coma+ - An Instrument that propels an Engineer to a Superconscious State, It is under development. It was preceded by Coma an instrument capable of performing multiple tasks, data acquisition, signal generation and multimeter.

AVR Assembler Tutorial – Gerhard Schmidt

Learning AVR Assembler with practical examples, Want to learn how to program AT90S AVR processors in assembler language? This is the page for you!

AVR Assembler Tutorial - Gerhard Schmidt

Erlernen der AVR-Assemblersprache mit praktischen Beispielen. Wollten Sie schon immer Assemblersprache von AT90S AVR-Prozessoren erlernen? Das ist die Seite zum Lernen!

Four simple programming examples with extended comments as first steps of a practical introduction to assembler programming: Sense and requirements, Simple programming examples

Converting a digital value to an analog voltage using a buffered R/2R network, including wave generation like sawtooth, triangle, sinewave forms and a small tone player application.

DG4FAC - Gerhard Schmidt

School Bus Conversion to Steampunk

He has many achivements to his credit; From converting a Thomas Saf-T-Liner, a flat-nosed diesel school bus into a family camper To a DIY Op-Amp Hot Tub Temperature Controller.

Look at Mr. Jake von Slatt, How he done things. This is what we learn from him …

Jake's School Bus Conversion and Other Projects

Jump into the problem and solve it, See the way a Creative DIY Enthusiast solves an automation problem at home. The Job gets done this way, such seasoned people are rare. Now the idea is …

Think - Deliberate - Draw - Build - Test - Install

We all get stuck at the 'Deliberate' step, If its team work, a few should leave the desk and the conference rooms and start Prototyping and Simulating. This helps understanding a tough problem. Better still find a fast and simple solution.

Then there is that Sensational Site That Jake Built - The Steampunk Workshop. This is where it all Happens.

LC Meter PIC 16F84 - Phil Rice VK3BHR

An inductance / capacitance meter by Phil Rice VK3BHR, Almost as published in Amateur Radio magazine, April 2004.

A Surprisingly Accurate Digital LC Meter

Phil Rice - vk3bhr - Home Page

"The AADE web site gave details of how their design worked and a circuit diagram. This led me to propose a design using their oscillator, but in a slightly different way. Like theirs, mine would measure the free running frequency of an LC oscillator, then successively apply a known capacitance then the unknown inductor (or capacitor)."



LC-Meter nach VK3BHR mit PIC 16F84

Der hier vorgestellte Nachbau des LC-Meter von VK3BHR, Phil Rice, verwendet einen PIC 16F84 und eine Punktmatrixanzeige. Der Messbereich geht in etwa von 0 bis 10 mH für Induktivitäten und von etwa 0 bis 100 nF für Kapazitäten.

Wide Skill Spectrum by Building a Robot

These valuable learning materials are partly derived from Robot Builder's Guide of Fred Martin, the course notes at the Massachusetts Institute of Technology.

Wide Skill Spectrum by Building a Robot

Basic Mechanics— Describes basic mechanics, friction, and the simple machines that comprise the building blocks of more complex machines, like robots.

Sensor Design -  Without sensors, a robot is just a machine. Robots need sensors to deduce what is happening in their world and to be able to react to changing situations. This chapter introduces a variety of robotic sensors and explains their electrical use and practical application.



Robot Control - The most common kind of robot failure is not mechanical or electronic failure but rather failure of the software that controls the robot. For example, if a robot were to run into a wall, and its front touch sensor did not trigger, the robot would become stuck (unless the robot is a tank), trying to drive through the wall. This robot is not physically stuck, but it is "mentally stuck"

delabs Notes

When you build a robot, you are dealing with Mechanical, Electrical, Electronic and Computer Technologies with the Interfacing.

The improvement in the Wireless Communication, Low Power Hi-Speed Semiconductors coupled with compact gigabytes of Flash/HDD may help build a Creative Robot with a smart brain.

Applied Magnetics by Barry Hansen

Barry Hansen enthusiasm for Coilgun Designs has created an EE education portal.

See the RLC Simulator and Inductor Simulator. By building a Gauss Gun which is like a Solenoid, Electromagnetic Relay or 3 phase contacter, you can learn electromechanics. This may be like a sequential solenoid which makes things move.This leads us to the Linear motor.

Applied Magnetics by Barry Hansen

There is also a very interesting learning article. PID in Control Systems in reading a DIY levitator design In Popular Electronics May 1996 - James Cicon.

Why build a coilgun?

It demonstrates many basic concepts of magnetic machines. A coilgun is foremost an example of a solenoid. These appear practically everywhere, from car door locks to doorbells.

(Youngsters Should do Basic Electricity Experiments with the Supervision and Guidance of a Technician, Engineer, Experienced Enthusiast or an Amateur-Radio Operator

My own interest into electricity-magnetism came with a failed Doorbell in my Schooldays, from collecting gramophone and chemistry lab parts i got escalated to the Iron-n-Copper Age - delabs)

ABACOM LochMaster - BreadBoard projects

A Schematic design has been made, either from experience coupled with testing out application note blocks together. It could also be trying out an idea from a Magazine. If you have simulation tools, you may want to simulate parts of the design and iron out some flaws.

Now if this design is small or made of tested blocks and maybe verified by a seasoned designer. Then you can move to pilot production of 7 Nos.

If you cannot afford the risk and the cost of iterations. Sometimes making the PCB may delay the design so much, that the "Time to Market" will be too long. Then you lose out to the competition.

So... or Hence or even Thus ... A quick Breadboard or Stripboard testing not only validates your schematic, but improves your design skills by making you more familiar with the components and their behavior. The real world limitations and the non-ideal electrical specifications of passives, semiconductors and chips too. This brings us back to the word Didactic. We should always have both the feet on the Ground.

I wrote this note above inspired by the LochMaster, few years ago.

ABACOM LochMaster - BreadBoard projects

LochMaster 4.0 is a developers tool for BreadBoard projects. It has useful functions for designing, documenting and testing project
boards.

G8NQN - Martin - Keadby North Lincolnshire UK

Amateur Radio Station operated by Maerin Bancroft. The Online Website includes a Technical section with drawings and building instructions for many projects.

G8NQN - Martin - Keadby North Lincolnshire UK

He has links to various sites that cover the RAE exam theory in detail, this section can be used as a reference for those taking the RAE at a training centre.

CI-V Interface Controller

As you can see the circuit is very simple, and uses the Max 233 CPP RS232 interface chip to control the data flow, this interface works very well with programs like Ham Radio Deluxe etc, and I am now using this interface on a daily basis.



So far I have only built this circuit on a small piece of Veroboard, but that's where all good projects begin, I am not going to waste time going into the construction of this interface due to its simplicity, however if you want any details please email me you can find my email address on QRZ.COM, (or join my forum) link to that on the homepage.

SpikenzieLabs - Kits and Projects

It is nice to see many building solutions over the Arduino base like this Prototino. Both hardware and software of Arduino are Extensible. This gives opportunity for New tools and Solutions over this compact system Framework.

Prototino an Arduino clone for Prototyping 

One Idea can be an Arduino with a CPLD and Universal I/O driver for robotics. This can come with a Visual IDE which is close or better than the old Visual Basic 6 in usability.



An Youngster can just Drag Drop Components and Link them to build his Robot or Home Automation Solution. Robotics Designers can have the option of looking at the code/hex if needed.

SpikenzieLabs - Kits and Projects
6135 de Maisonneuve West, Suite 12, Montreal, QC H4A 2A3, Canada.

Step Down Capacitor - No Heat

Sometime in the eighties, I had to change a blind timer design due to non-availability of a component. A high resistance relay 600 ohm coil was not in supply, 150E was available. The Power to timer was derived from a resistor, I put a 0.47uF 630V and it Worked !. This design of mine, deriving a low voltage from a capacitor shown on right adaptation became popular. I used a 0.47uF 440V AC or 630V DC Plastic Capacitor.

Schematics of delabs: Mains Voltage Indicator

This circuit has been drawn from my memory and i have not tried it out again, just see if it is ok and then try. You should use the fuse of 100mA a slow blow if you want but it is very important. This circuit has to be enclosed in a plastic sealed enclosure to avoid contact.

Mains Voltage Indicator with a LED

Mains Current Indicator with a LED

You should use the fuse of 1A a slow blow if you want but it is very important. You can design the shunt R3 and Fuse rating as required by your load. Note that this circuit is to be put in series with the load like an ammeter. If you put it across the supply like a voltmeter it will fuse out or burn out. This circuit has to be enclosed in a plastic sealed enclosure to avoid contact.

Schematic to Reality a nice Perspective

Without Audiophiles and Ham-Radio enthusiasts, the field of Electronics would be Dreary and Gloomy.

From Schematic to Reality

Here is a nice page with refreshing illustrations, this page helps initiate a Electronics Newbie in the complex science of Schematic Reading.



Phantom Power and Microphone Interconnect Basics

What's that you say? You don't know your AC from your DC' Audio is considered an Alternating Current, a.k.a. "AC." (So is 120-volt "wall" power.) But electronic circuits need Direct Current (DC) to turn them on, from batteries or power supplies.

The Electric Web Matrix

DIY Pages and Know-How for those who love vacuum tubes, computers, and hearing music in its pristine form. There is an Audio and Electronics section is for the DIY computer audiophile.

My Notes - Even though i had Electronics Junk in my lab, when i was at school. (I used to call it Nuts-n-Bolts) The first project i saw being built by a friend was a Guitar Pickup using Germanium Transistors/Diodes. This was my first semiconductor schematic reading. Get into electronics now with a Audio Project, or ....

Alternative Energy Projects - MTM Scientific

Here are some neat projects for your study, free learning material. Solar Oven Cooker, Anemometer Circuit, Simple Data Logger.


The MTM Scientific, Inc. Experimenter Corner

Highlights are How to Measure the Power Output of Solar Panels and the Time Controlled Relay Switching Kit.

They also sell a Battery Amp Hour Meter and a Crystal Diode set which contains 1N34A diodes, 1N60 and D9B for learning electronics. They are Germanium Diodes.

An interesting Energy solution is the Hand Cranked DC Generator Plans. It describes how to build a hand operated electric power generator using a standard DC gearhead motor.

Solar Tracker Circuit Kits helps you servo position your Solar Cell Array, you can build a device which will automatically follow the sun across the sky.

Alternate Energy Plans by Lee Bell

At the PackRat WorkShop Lee Bell has archived Power-Energy Ideas, Mechanical Howto and Robot Designs too. A Practical Man, His drawings are a language by itself. He has created a useful resource which will keep a DIY Enthusiast busy for many months.

Alternate Energy Plans by Lee Bell

"I already had a marine deep cycle type battery and an alternator that someone had traded me a while back in exchange for a 1hp dc treadmill motor. He was building a windmill and the car alt needed too many rpm's for what he wanted to do. I think it's a standard GM type." - Lee Bell



delabs Notes

Alternate Energy, storing and managing your own small power source, are an invaluable asset for Home or Small Business.

Depending on oneself, not only develops skills but also keeps you in form always. Building an energy source cost-effectively, requires you to put in a lot of learning and building efforts.That itself may become your future Small Business

Remember Fossil Fuels are Running out fast, Only Internet Communications and Alternative Energy will keep Business Blooming.

The lifestyle has to change, The future Generations are going to face the Heat, or is it Bitter Cold ! Even Freezing ?

Coal and Steel with Steam brought about the First Industrial Boom. Then Oil created unprecedented Magic, the Second Technological Revolution. This will not last long. If only Rover found Oil in Mars, this post was not needed.

Single Digit Voltmeter with LM311

I wanted to design a logic probe as a tutorial, but there were many good ones in the web so i have tried to design a single digit voltmeter. This circuit is a design, i am unable to test it now, later if i test it and find mistakes i will update this page. You can help me by pointing out the errors.

Single Digit Voltmeter with LM311

First bear it in mind that it is a single digit voltmeter which is 0-9 counts only on the positive side, that is it can measure +0 to +9V DC +/- 1V error. That may not be practical for the cost of the components above. It may be used as a toy logic probe. The reason for the circuit is not for usage, but to give design ideas. The methodology used is Gut Feel - Thumb Rule method.

First i explain the simple part, D1 a seven segment common cathode LED display is chosen as CD4511 is a sourcing driver. 4511 can be latched so it has been used here, it decodes binary 4 bit decade info to seven segment output. The four bits are derived from CD4029 up-down clock pulse counter. LM311 is a analog comparator with single supply capability which is the A-D interface.

To avoid resistors for each of the LEDs the LEDs are turned ON-OFF at 10KHz 50% duty cycle. The Nand Schmitt Trigger CD4093 is used as in IC4D as a 10KHz Clock which drives T1 transistor with a resistor R5. On turn on IC4D one input is high which is pin 12 pulled up to +5 and another Pin 13 is Low as C4 is in discharged condition in NAND gate both inputs high, gives a low output, the other combinations the output is high. So the output goes high, this starts charging the cap C4 which soon makes both inputs high, which in turn makes output low starting the discharge of C4. This is now evidently a endless loop, hence it is a oscillator. R*C = T .... 0.01uF * 10K = 100uS or 10KHz as F=1/T approx or better still multiply by 1.1 ?. I am not good at formulae but i manage with a calculator.

The supply and ground pins of CMOS chips have not been shown, see datasheet or earlier circuits.

IC4A is also a oscillator but slower which is good enough, it is slow so that a measurement can be made nearly every second. The IC4A slow clock is read by 4029 which produces a count-down binary nibble at Q1....Q4, This is converted to crude analog with R1...R4. The voltage generated is compared with the voltage you are measuring by LM311 which generates a Latch pulse to 4511 to freeze the reading where both voltages match.

Method of Operation :

IC2 is a Counter in Decade-Down mode and IC3 is a BCD to Seven Segment Decoder which Drives the Display D1. The Circuit is wired in such a way as to keep counting the Pulses from the Clock IC4A. The IC4A which is wired as Schmitt Nand Oscillator Clocks the Counter. Now to understand how this Counter and display works see this Interactive Tutorial Simple Digital Counter. For every pulse at Pin-15 of 4029 the Counter Counts down from 9-8-7-6.... and so on. But the Display is Latched by IC4C, So the Display is static even when counter is running. So while testing counter you can remove IC4C and keep LE Pin-5 of 4511 low to ground. For testing this Circuit you can use the manual clock with a pushbutton (single step) or a slow clock rate 1 Hz as in the Tutorial Simple Digital Counter.

The Transistor T1 and Oscillator IC4D is to chop the power to display at a fast rate, this avoids the adding of seven resistors. This is not required, but it saves power and reduces parts count. IC4B is is like a ON indicator, it is a spare gate.

The BCD value at output of 4029 Q1-Q4, four bits, a nibble, is converted to an analog mV value across R6. The resistors R1-R4 which are connected to Q1-Q4 have weighted resistor values for the BCD 1-2-4-8. By ohms law you can understand that the analog value across R6 is approximately proportional to the BCD value. This circuit is just a single digit A-D converter, not even as good as 4 bit converter. Which means approximate value of analog at R6 will do.

Now lastly LM311 is a Comparator, it compares the Analog BCD reference at Pin-3 and the Attenuated Input signal at Pin-2. Output Pin-7 goes high when Pin-3 voltage becomes less than Pin-2. This is made to a narrow latch pulse by C2-R12-IC4C. The latch pulse freezes the BCD data to display till the next latch pulse. R8-R9 attenuate the 0-9 V DC input to a 1/100 value. The zener Diode Z1 is for protection.

I guess the LM311 circuit should work off a single supply, but a dual supply may be required as voltage levels may be near zero. You must be able to see a staircase waveform or ramp across R6. Narrow Latch pulses at Pin-5 4511 on every ramp cycle.

Phoenix Science Experiments

Phoenix allows you to develop science experiments  by connecting  sensor / control elements to a computer and access them through software.

Phoenix Science Experiments

Phoenix depends heavily on Python language. The data acquisition, analysis and writing simulation programs to teach science and computation.

Different sensors elements can be interfaced and accessed by few lines of Pythoncode. Phoenix utilizes the power of personal computers for experiment control, data acquisition and its mathematical analysis.



PMDK is an easy-to-use, low cost micro-controller development system. The hardware consists of an ATmega16MCU, LCD display and regulated DC supply. All the I/O pins of the MCU are available on sockets.

The instrument is designed using locally available low cost components and the design is freely available for commercial production. Design supports hardware plug-in modules for expansion. Phoenix is developed using Free Software tools.

The serial and USB versions can be easily interfaced to a PC. They can also be programmed through the serial/USB ports after uploading a bootloader program to ATmega16.

Amateur Radio and Calculators for Electronics

John Owen has made Enriching Electronics Pages at vwlowen.co.uk. There are many Ham Radio projects too.

Amateur Radio and Calculators for Electronics

A highlight is the "Build A PICAXE Weather Station." This is quite Exhaustive and Detailed.

Starting Electronics - a simple first project.

Here he teaches in simple tongue, The method and steps to towards the first project and that too, with the Sacred SG555 Timer.

Collection of calculators, ready-reckoners

Here is where he dazzles, He has developed very useful Calculators to make your Numbers Game a Piece of Cake.

MiscEl - Many Electronic Calculations

A swiss army knife for the Electronic enthusiast. This single program packs many applets that help you overcome the Formula Amnesia and even Poor Math Skills.

MiscEl - Many Electronic Calculations

The program contains a lot of pages with different electronic calculations. Each page contain one or more different calculations.



Science calculators are on Geometry and Periodic table. Some Electronic Calculators are shown below

• TinyCalc Can do the same as the entry line in Calculator, but is very small when pulled out.
• Ohms law Ohms law, impedance of capacitor and inductors, complex power
• Waveforms Calculates RMS, mean, PEEK, DC, FFT for different waveforms.
• Thermo sensors Calculates for PT100, NTC and all types of thermocouples
• Series/parallel Calculate/design series/parallel connection of resistors, capacitors and inductors

Radiocalc or dBcalc - Conversions RF Engineering

Besides classical functions and dB conversions, RadioCalc includes a converter of Power to field strength commonly used for EMC/EMS test-set-up. Also impedance can be represented as a function of reflection coefficient (somehow like an electronic Smith-chart). This and many other functions are obtained by clicking into the arrow of the "Conversion off" window.

Radiocalc - Convertisseur Radio Universel



Thanks to RadioCalc the different dB charts are obsolete by computing the ratios of Power (W) or Voltages (V) according to dB = 10*log(P2/P1) ou dB = 20*log(V2/V1).

Just for a trial : type 100/10 (or just 10) and push the dB button as the 'W' mode is chosen, the result will be 10 dB, then choose the 'V' mode by clicking in the V button (in the Quick dB window) push again dB, the result is now 20 dB.

From - Temcom - Consulting for test & measurement and electronics in France
(This was Earlier Radiocalc, i have now updated the link to the new site in France)

Electronic Inventory Online - Parts-n-Kits

High quality new & excess electronic components, such as: Batteries, LCD's, LED's, Power Supplies, Switches, Fans, Cables, Development Tools and more.


Electronic Inventory Online - Parts-n-Kits

eio is a versatile electronics surplus source associating information with the distribution of electronics, computer and optical materials. They have very good bargains in some categories.

Lumileds LXHL-MWGC Luxeon

LED Lighting, One Watt of Warm White light. 20 lumens at a Wavelength of 3300 K.

Shop at Electronic Inventory Online

Electronic Inventory Online, Inc.
22412 Normandie Ave. Unit #A Torrance, CA 90502 (USA)

delabs Notes

A Warm White LED is great Feng Shui for a Hobbyist's Desktop or Workshop. A DIY Table Lamp or a Lathe Lamp with these Warm LEDs create Positive Energy, for not just your Home but for the Entire Neighborhood. This idea, is in the form of riddles in Ancient Chinese Manuscripts, I hope the Yellow Emperor does not see this post.

Yellow Emperor - Known as an early inventor. He holds the patents for The South Pointing Chariot, Diadem, Football, Silks, Dyes and Grain Farming too. A Musical instrument called Guqin too!

Electronic Surplus - Obsolete Rare Components

They are Experts with hard to find electronic parts from audio ICs and devices, to transformers and relays. An inventory that is made up of obsolete and active items.

Electronic Surplus - Obsolete Rare Components

Surplus Electronics: Switches, Capacitors, Transformers, Connectors, Motors, Meters & Analog Indicators, Semiconductors and More.

Sell or Dispose your stagnant inventories or unused items to Electronic Surplus. This is a Green Solution, Recycle, it also helps small entrepreneurs do something new. Remember old parts may corrode and get infested if idle for long. Electrolytics and Batteries do not have a good shelf life.

"E.S.I. was started by Clyde Daniels back before 1930 when he was selling all types of material he then progressed to Military surplus after World War 2 when his son Dick joined him after serving on PT boats in the Navy and Dick mother Ida Maye completed the family operation."

Electronic Surplus Inc
8755 Munson Road #6, MENTOR, OH 44060

Electronix Express - For Schools and Industry

Distributor of electronic components, test equipment and tools. Custom electronics kitting and value-added services.

Electronix Express - For Schools and Industry

Some of the products they supply include Anti Static Products, Toolkits, Soldering related, Inductors, Logic Probes and Pulsers.

A Benchtop Multimeter,  4 ¾ digit, 40,000 count true RMS AC with Built-in USB & RS232 Interfaces.



Bench Digital Multimeter DM422B

Other features -• Data save and recall with software, Triple display, (main, sub-left, sub-right), 40 segment bar graph display, duty cycle, Temperature function.....

True RMS, USB & RS232 Model

Electronix Express
900 Hart Street Rahway, NJ 07065, USA

All Electronics - Pre-owned or New Parts and Equipment

This is a easy to use Electronics Component eStore. And so well sorted and Boxed. They also buy unused Inventory or surplus from You. They specialize in electronic and electro-mechanical parts and assemblies.

All Electronics - Pre-owned or New Parts and Equipment

From robotics, electric trains, surveillance, remote control models, antique radio restoration to Used Parts and Assembly; They have it all for the student, hobbyist or even that rare Inventor. Since 1967 they have this service, nearly a year after i was born. They are as old as Me.

All Electronics Corporation
14928 Oxnard Street, CA 91411-2611, USA

LM3914 - Versatile and Easy use Display

The LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a linear analog display. A single pin changes the display from a moving dot to a bar graph. Current drive to the LEDs is regulated and programmable, eliminating the need for resistors. This feature is one that allows operation of the whole system from less than 3V.

LM3914 - Versatile and Easy use Display

• Drives LEDs, LCDs or vacuum fluorescents
• Bar or dot display mode externally selectable by user
• Expandable to displays of 100 steps
• Internal voltage reference from 1.2V to 12V
• Operates with single supply of less than 3V
• LED driver outputs are current regulated, open-collectors

The circuit contains its own adjustable reference and accurate 10-step voltage divider. The low-bias-current input buffer accepts signals down to ground, or V^-, yet needs no protection against inputs of 35V above or below ground. The buffer drives 10 individual comparators referenced to the precision divider. Indication non-linearity can thus be held typically to ½%, even over a wide temperature range.

My LM3914 Circuits

Millivolt Meter using a LM3914 LED Dot Display

• Mains monitor LM3914
• LM3914 analog display

Circuits and Projects of LM3914


LM2941 Manual Fan Regulator & LM3914 Voltage Monitor - The LM3914 voltage monitor is also straight forward. As told I use only 6 of the 10 led outputs. A voltage divider on the input (R1-R2) decreases the 7-12V input to about 1.96-3.36V (x0.28). 

Novel white LED torch - LED bargraph readouts, here the LM3914 is used as the basis of a 10-step variable brightness current-regulated white LED torch!

Indikátor napětí autobaterie s LM3914 - This is actually a voltmeter that the size of the measured voltage signals using ten LEDs. The level of which will illuminate the first LED and the lights can be set to last.

Bauplan Schaltplan Bargraph Anzeige mit dem LM3914 - Analog displays have the undoubted advantage that you can get a reading very quickly perceives visually compared to digital displays.

Stereo Digital Camera Sync Shepherd - R7 sets the current through the LED's of the display. With R7 of 620 ohms, the illuminated display LED draws about 20 mA, which is about maximum for this display,

DIS*PLAYER: Theory and Construction -  This device drives ten LEDs in a linear display, with programmable endpoints and the choice of "dot" or "bar" modes of operation. Furthermore, it is possible to "chain" multiple devices for displays of virtually unlimited size. 

Wireless Home Power Monitor - Tweet-a-Watt

This is an Embedded Project using a XBee. Makes an Energy/Watt/Power Meter into a Wireless Intelligent Sensor.

These Sensors are Interfaced to a PC using another XBee. The Data Acquired can be Displayed(monitor), Logged (sql/csv) and Analyzed (graphs/reports). Then you can form a set of Green Resolutions and Implement them.

Tweet-a-Watt! A safe and simple wireless power monitor

Tweet-a-Watt starter pack

Monitor upto 1.5 KW, You have to own a Kill-A-Watt device to Add-On this Kit to Web Enable it. Each plug transmits the power usage at that outlet to a central computer receiver. The receiver can then log, graph and report the data.

OscilloScopes for the DIY Enthusiast

Here are some Hobby Scopes that might even be quite professional if you develop them further. They are virtual instruments. Making Scopes with tablets may be much more easy now.

The µSCOPE - A poorman's oscilloscope
The oscilloscope is still one of the most important measurement tools of the electronic engineer. With the advent of the often very reasonably priced USB scopes, such an instrument is now within reach of every body.



Digital oscilloscope - Build a simple Inexpensive digital oscilloscope. Single channel, about 100 MSPS. RS-232 based.

xoscope is a digital oscilloscope using input from a sound card orEsounD and/or a ProbeScope/osziFOX and will soon support Bitscopehardware. Includes 8 signal displays, variable time scale, math,memory, measurements, and file save/load.

xoscope - digital oscilloscope for Linux

MHZ100Q is a low cost FPGA-based high speed data acquisition system. Version 2 is a standalone board containing 2, 100MHz 8-bit A/D channels, preamp, 7th order elliptical antialiasing filters, and a Xilinx FPGA.

MHZ100Q - Open Source FPGA-based 100MHz A/D

A USB interface is implemented in the FPGA firmware. Power comes from the USB bus. Schematics, VHDL and Verilog source code, and signal capture and display software are available and being posted.

• Oscilloscopes in Test Measurement
• Open Hardware Design - BitScope
• Open Source Android Oscilloscope
• DSO Nano - Digital Storage Oscilloscope

The Incredible 555 Timer

The Incredible 555 : Here are some 555 circuits, The most versatile and simple chip of all time !

Some of my 555 Circuits are at my blog - 555-Circuits - delabs Schematics

The best part of the 555 is that it has an voltage detection. It has a Versatile Logic which is defined by voltage comparators. The ability to loop it like an opamp for feedback makes it the first "Programmable" Mixed Chip. In short it make an ideal building block.

555 The most Incredible Chip - At my Learning-Teaching Blog Solderman Basics.

Signetics made the 555, This is one IC that is like a E-LEGO, this along with Op-Amps and other components can make many interesting projects. On some pins like Control Voltage it responds to analog signals and on Reset and Output the signals are Digital like. The 7555 a CMOS version consumes lower power and oscillates at higher frequencies.

555 Timer Circuits at delabs



555 Timer based Circuits

• Pulse width modulation using 555.
• Fixed frequency variable duty cycle 555.
• 555 watchdog for uC and uP systems.
• OR gate with two 555.
• Drive SCR thyristor with 555.
• LM555 Voltage Doubler.
• 555 based Reset Generator.

CAn Remote Automation-Control with AVR

CARACA is a home automation project based on a net of interconnected programmable circuits suited to perform different tasks like switch on/off appliances, decode commands from Ir remote control units, control thermostats, measure temperature and more.

CAn Remote Automation-Control with AVR

Every node of the net communicate each other through a robust protocol (CANBus), and the status can be monitored by a PC possibly connected to the Internet.



Other Open Source Home Automation Projects

MisterHouse: Home Automation with Perl
MisterHouse is a Windows/Unix home automation program written in Perl. It can respond to voice commands, web browsers, time of day, serial port and X10 data, external files, etc and can speak via Text to Speech engines.

OpenRemote - Home of the Digital Home
Software for the Internet-enabled Home at openremote.org. An Open Community in the Home Automation and Domotics space. We believe an Open Source approach can revolutionize the way people create, install, and maintain software in the industry.

BricoGeek.com - Gadgets Gizmos and Arduino

A Geek How-To , Gadget and Arduino Community News site run by Oscar Gonzalez form A Coruña in Spain. From software programming, electronic projects and DIY Gadget Gizmo hacks.

BricoGeek.com - Gadgets Gizmos and Arduino

Arduino Nano is like the Arduino Mini, but smaller. Allows rapid prototyping on a breadboard.
Comes with chip version 3.0 ATMega328. ICSP connector for external programmer. USB mini-B connector for programming and serial communication. Integrated voltage regulator. Pins-spaced 0.1 "DIP for insertion directly on a breadboard