dapj Tech

An online EE Resource centered around Electronics Engineering Technologies. Product Design, Instrumentation and Automation.

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Friday, October 02, 2020

PLC based PID Controller

Below is a Electrical Control Panel, It has a Strip Chart Recorder which is electro-mechanical, It has a PLC Inside. A handheld PLC Programming unit. The computer is showing the Ladder Logic Program. PLC is based on a embedded uC. The DIN Controllers are Analog + Digital circuits.

Process Control Application Notes

So you see it is a Electrical Control Panel with Electronics and the PLC Ladder Logic means, Software too.

PID Controller PLC

Electrical Control Panel Wiring

This is a PID Controller based Control Panel using a PLC. The Computer is a 386 40MHz with 40MB HDD. The printer Epson dot matrix, The worktable is an inhouse design made of steel and plywood, capable of withstanding heavy loads.

You can also see a Stripchart recorder for the temperature logging and PID curve study. This controls a Steam Valve with 4-20mA output.   

Design Service and Custom Projects

Some old examples of open custom designs. these were made to educate the customer and also study the capability  of online communication and and collaboration tools for such activity.

Two Stage Sequential Timer Docs - 

The circuit is a two stage sequential timer with auto reset. It can turn a Solenoid On/Off after a Sequence of delays that are preset. This is also a basic example of timer usage in automation.

Design Documents

All Timers are 1 - 30 Secs Analog with Presets to adjust with a screwdriver. The Switch, Solenoids and Power supply has to be via terminal blocks or plug-jacks. The PCB may be upto six Square Inches for standard DIP components but with SMD it may be smaller.

delabs Design Service and Custom Projects

Four Channel Temperature Alarm Docs

The temperature in a pipe is monitored with four RTD Pt-100 Sensors, The type of probe could be Extruder RTD probes with Bayonet or Compression Fitting, Get it from Omega. To keep costs low you can choose small thin film RTD sensors, they will be fast but on rough usage may break.

Design Documents
The time taken to measure the temperature at the 4 points will be less than 4 seconds. An optional display of the measured temperature as shown above can be avoided by using a DMM to adjust the setpoint.

The Analog Timer Module can be set from 0- 30 minutes. If out-a remains high even after set time a out-b alarm goes on to sound a buzzer and flash a LED light.

Thursday, October 01, 2020

The Timeless Performer 555 Chip

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

Thursday, September 03, 2020

delabs PDF Circuits

I am now Organizing and Updating my main product design sections. Many Useful Websites and Nice Firms have gone over the last few years. I had to update to remove many broken links and improve navigation. These parts of my websites partially represents my Test-Measurement and Instrumentation firm i ran for some years. It also contains many of my designs and circuit innovations from my early days.

2020 -  The HTML pages are now Responsive from Computer Tablets, Notebooks to Large Monitors. All sites are SSL means https: Private and Secure.

delabs PDF Circuits

In 1999 most of my circuits in the OrCad and PDF Formats were uploaded as zip files in free websites of Netscape and Tripod. Then i got suggestions, Feedback and Thank you letters from all round the world. Later some support, encouragement from enthusiasts and engineers in the US and Europe made me improve the Websites "CMS" and content organization. I am now updating my Plain old HTML Pages for the 4th time in 15 Years.

delabs PDF Circuits

Some parts of delabs/dapj use the CMS Technologies of The LAMP Stack  that arrived later. The New Tech Blog areas link  many EE firms and Resources all over the world. The tech cladistics i developed and used to organize my content is intensive.

Please note these technical pages are for Electronic Enthusiasts and Engineers around the globe for Reference and to improve basic Design capabilities.

These pages or ideas of delabs technologies and dapj tech cannot be copied, replicated or used for content development online or offline print materials.

Instrumentation and Industrial Design

EE Design Library

This is a curated list of EE Pages from delabs websites and blogs. It is an attempt to organize delabs created ee reference pages in one place.

Analog Product Design - Here are design aspects of circuits using Op-amps and Comparators. Discrete Semiconductor Circuit design like using Transistors and Diodes. RLC parts.




EE Design Library

 Electronic Design  - Things related to Electronic Design in all its aspects. That includes the prototyping, mechanical, electrical and PCB. Product Safety, EMI-RFI, Reliability and Robustness.

Embedded Systems - This Section is related to Microcontrollers and Related Resources. Microcontroller, SOC, FPGA, ASIC. From 80C31 to the Latest  chips will be the scope of this section.

Power Electronics - The design of Power Supplies, DC to DC and AC to DC Convertors, SMPS, High Voltage and High Current equipment. Mosfets, Thyristor, Schottky Diodes, Ferrite Magnetics and Chokes are the various components used.

Components Materials  - Electronic Components and Engineering Materials. The parts, kits, tools that are used in designing and manufacturing electronic products. The Mechanical Nuts-Bolts and Raw Materials used in Electronic Manufacturing.

EE Design Library - Electronic Product Design Resource.

Measurement is everything, and an Oscilloscope is a EE Stethoscope.

delabs Technologies - Product Design - Industrial Automation and Instrumentation. delabs Technologies uses the brand names delabs and dapj in its Web Services and Resource Sites. These together form an Electronics Informatics and Product Design Technologies Web Consultatory.

Electronic and Instrumentation Tables

Tables, charts, quick reference cards, booklets and handbooks; are the most versatile tools of learning and putting the learning into applications. These should not have a lot of language or flowing text. These are - to the point, easy to remember, graphical, colorful (memory aid).

Electronic and Instrumentation Tables

Just like a circuit diagram, flow chart or ladder logic can graphically interface with a human mind, Tables and Charts easily embed into ones memory.

Electronic Tables and Charts

Sunday, August 09, 2020

MCS48 Code for 80C39 Microcontroller

80C39 is a Cmos Version of 8048 the one that preceded 8031-8051. MCS48 is the set for that, MCS51 is the current set.

Here is an example project for 80C39-8748-8749 microcontroller. This code was written by me, and it works. But the documentation is not complete or may have errors.

80C39-8749 MCS-48 Examples and code.

Process Controller code here 80C39 Code for MCS48. The circuit for these are on this page along with other circuits.

This may be difficult to put together now. But the code and hardware is near compatible to 8051 uC. Now there are may types of ADC and uC.

The circuit of the Analog Front End was a V-F Converter

Analog Front End was a V-F Converter

This was supposed to have Analog in and Analog out. Some parts of the circuit may be in the 80C51 page. This has ramp-up and ramp-down settings for the Increment and Decrement buttons. This helps setting setpoint quickly. There is also debouncing for the pushbutton.

Tuesday, August 04, 2020

Electronic Engineering Resources

Sponsored EE Resources - This section is being added to financially support the delabs internet resources spanning many domains and blogs. Request a Sponsored listing here using the delabs Contact Form.

Electronics Engineering and Technologies

Sponsor or Donate - You can donate using PayPal to support the work of delabs and dapj. When you donate USD 100 and above you will be listed in the delabs page with your Website or Blog.

Sponsor or Donate to delabs

Your Company or Business also will get a free listing for Five Years as a Sponsor in our Electronics Resources Directory, in an appropriate category. This listing will also be mirrored at Electronics Resources. Request the Sponsored Listing using our Contact Mail form.

Some Electrical and Mechanical pages closely related to Electronic Manufacturing and Industrial Engineering will also be listed here. Each Subject page is also a Stub for listing and recording the specific subject related writing and posts of delabs in various other blogs and sites.

Categories of EE Websites of Firms and Resources

Sunday, August 02, 2020

Power Electronics and Mains Power

Updated pages, and integrated new pages with some explanations. These are related to mains power and power electronics.

Power and Energy - Mains Voltage and Power Circuits

Electrical Power can be used for most anything. It also can be stored and used later using Batteries. Alternative Energy Solutions like Solar, Wind and Tidal are providing new sources of Energy.

Fossil Fuels are running out and we have to become more energy efficient. Notebooks and Tablets are fast replacing desktop computers. Network servers and Cloud Solutions still use more power than needed. We have to use power for Productive and Creative activities.

Wastage of too much power leaves a mark, a carbon footprint, we also should shift to the low safe voltage standard of 24V. This will make conversion and distribution safe and solar energy friendly.

Power Electronics & Energy Systems

Power Electronics & Energy Systems

Tables related to Power Electronics

Discrete devices and other circuits

Friday, July 03, 2020

Theory- Electronics and Instrumentation

Learning electronics in theory by studying books is the conventional way, this method may help in History and Maths. Maths needs a paper and pencil for practicals and history needs a well equipped Library. In these modern times, the web has made access to wide range of learning information easy, which is true Knowledge Empowerment. The greatest gift a Child can get from the Parents or School, is Knowledge.

Electronics Theory and Tutorials  

Process Control Instruments - These are some instruments i manufactured when i used to run my own industrial automation business.

Theory- Electronics and Instrumentation - delabs

Now many Virtual Electronics Workbench Software and Interactive Tutors are available, these aid learning. We have to design, build and apply some electronic ideas in 3D Hardware, for complimenting the Book, Academic or Web learning.

Practical and Theoretical study in electronics has to be in Tandem, this is possible only when Industry works with Universities to create real talent and skills in students. The applied technology is evolving, hence the academic education must be relevant when the student gets into his first job.

The Evolution of Temperature Control

A closed loop controller is the heart of an Industrial Automation System. Right from an On-Off Hysteresis Controller to a Auto Tune PID Controller, we find solutions of different complexities. Each solution might suit a particular system; depending on the requirements of Ease-of-use, Cost and Process Type.

The Evolution of Temperature Control

A PC based multiplexed scanner controller with data-acquisition cards and I/O Cards can be solution for Laboratory or Research. This is used when real time control is not required or where the control failure will not lead to damage or loss.

A PLC or Microcontroller based controller should be used with a Analog Controller Protection or Over temperature Trip-Alarm.

Thursday, July 02, 2020

Electromagnetic Relays and SSR

Solid State Relays - These designs were improvements i made on the Application Notes of Motorola Semiconductor (freescale) and Thomson CSF (stmicro) Thyristor Data. The parts are still available, now made by other firms. You can also find similar equivalents.

Solid State Relays - SSR

They are called SSR as there are made of semiconductors and have no moving parts to wear out. They do generate heat depending on load and switching. Thyristors are used in most as they are rugged, mosfets and IGBT may also be used for various applications.

Electromagnetic Relays and SSR

In this section you will find SSR designs and PCB layouts which you can study. These were made and sold by me years ago. So the PCB layouts have gone thru some revisions and they worked quite well.

Friday, May 08, 2020

Electrical Control Panel Wiring

Control panels are a part of industrial automation. It contains many DIN standard instruments both in the front panel and inside back rails along with the wiring. They are called panel mounting and rail mounting. Cable management is a Science in these equipment.

Just like rackmounts hold big instruments or computers, control panels small or big have to hold DIN Instruments, switches and annunciators to make it easy for the operator. The maintenance work also is simple from the backside. It can be kept near the machinery which it controls.

Electrical Control Panel Wiring

Some Control panels go into Control Rooms at a distance away or at a greater height from the shop floor. This way they can monitor and give instructions while managing a larger process like processing of chemicals and at the same time safeguarding the instrumentation and computers with controlled environments.

Some example circuits of panels here Electrical Control Panel Wiring

delabs Technologies

Temperature Measurement and Control

Temperature Controller 48-96 - A 1/8 DIN Indicating Temperature Controller. This is a Analog Controller built around ICL7107.

Temperature Measurement and Control

This is a 48-96 DIN Temperature Controller, it is mains operated, it is in a Industrial Plastic Housing. It is not meant for very harsh environments. Suitable for Control Panels in Control Rooms. It has a accuracy and linearity of 0.5%. It had options of on-off or time proportional control

Temperature Controller 48-96

J and K Thermocouple with 4-20 mA

Temperature is the most common process parameter, Pressure seems to be next. Flow, Humidity, Strain, Torque, Level, RPM, Distance and many more follow.

When a physical parameter let us say distance is measured, we first need a sensor that converts it into electrical values, digital, pulses(events/limit) or analog. The sensor used for length is a Linear encoder and it creates the electrical information for the DRO to Display.

Mixed Circuits Analog with Digital

Digital Interface to Analog Circuits is an example of Mixed Signal Design. Generating Digital Control Signals from the Analog sections in instruments is also done by Mixed Signal Circuit.

A/D Convertors and D/A Convertors are like Mixed Signal Chips. A Digital Potentiometer that controls an analog signal amplitude with a digital byte or word, figures in Mixed Design Circuit.

Analog Designs have to handle Linear Signals, Like 2.03 V and 35.3812 mA. Waveforms of all shapes from Straight Line DC Levels to the Jittery and Multi-Frequency Audio Waveforms.

Mixed Circuits Analog with Digital

350 MHz Mixed Signal Oscilloscope HMO3524 by HAMEG Instruments

HMO3524 by HAMEG Instruments

Mixed Signal IC or ASIC are chips that are mainly Digital on the Core but have peripheral I/O within the chip to interface with the real world outside, over Analog Signals. Sensors and Actuators use signals in the analog language. The CPU with its Math Power, speaks Digital Words, its behavior thus can be patterned by a Software Program.

Fluid or Water Level with Reed Relays

Some Circuits on above pages are..
  • Voltage to pulse converter using opamps
  • Analog Section of 8751 based flowmeter
  • Voltage to pulse converter impulse counter
  • 16 channel analog multiplexer
  • 8 channel analog mux with sample hold
  • Digital Control for 8 channel analog mux

Monday, March 30, 2020

Basic Electrical Circuits

Electrical Engineering encompasses Everything in Electronics. Communications, Computers etc. are further specializations of Electronics. So it is best to Identify Electrical Circuits with Electrical Designs which excludes Active Devices. It can include Electronic Products in the form of wireable modules.
So House and Factory wiring, Appliances like Ovens, Toasters, Power Generation and management; all these are electrical. Motors, Generators, Connectors, Relays, Contacters and Circuit Breakers are Electrical Components.

See a diagram i made for a Sequential Process Control Unit, custom built for Vacuum Impregnation;

Sequential Process Control - Vacuum Impregnation

A Radio or Power Inverter is Electronic. When an Inverter or Electronic AC-DC Motor Drive is used in a Control panel or Power Supply system, that integration is shown as an Electrical Circuit. I feel Simple Consumer Electronic Circuits using Diodes, Transistors, SCR, Capacitors and Resistors can also be taken under electrical circuits; when they are used in Mains-Power or Household Appliances. Solar Energy related circuits also can be studied under Electrical Power Circuits.

In Electronics RF-Microwave and Communications is a specialization area, Computer Hardware, Software, Internet form another major domain. Networking and Wireless data communication overlaps both the above.

Power Electronics and Instrumentation are fundamental domains needed for many. Industrial Automation with Process Control Instrumentation is unique, but is supported by the fundamental domains. Many more finer areas like Robotics and Medical Electronics have a much sharper focus.

Basic Electrical Circuits - delabs

delabs Technologies

Embedded Microcontroller Systems

Analog devices like transistors and diodes lead to opamps and analog computing. This takes more parts but with fast devices can be real time. Then came Logic and Digital Circuits, here also big systems will take too many parts. A very Old hp Logic Analyzer instrument, could be HP1607A, had more than five large PCBs, Toggle Switches and numerous 74Fxx TTL Chips. I tried to revive it, it could not be fully restored.

Embedded Microcontroller - delabs

Then came the solution the Microprocessor. Here the entire system goes into the firmware and a Hardware Tool Set in the Microprocessor made up of Logic and Math is sequentially used to perform the same operation that would require innumerable Gates in a plain hardware digital circuit. But as it performs the operations one after another, it takes time and is defined by the CPU Clock Speed.

Embedded Microcontroller - delabs

When the External RAM and EPROM and other peripheral devices moved into the main package, MicroController were born. When more external devices merged with the MicroController. It formed a nearly complete computer, this is known as the SOC.

Mains Voltage and Power Circuits

Mains Power means the 230 V AC 50 Hz or 110 V AC 60 Hz in some countries, The lower power line like 5A is used for small lamps and fans. The higher power line 15A is used to drive the High Power Electrical Appliances like Heaters and Motors. This is a single phase supply.

Mains Voltage and Power Circuits

Single phase Supply in layman language means a Live, a Neutral and an optional earth. The earthing is a must in every building along with lightning protection. The Neutral is a close to earth potential, The live can give a shock to a man who is in contact with earth at some part of the human body. So great care has to be taken. This live wire or point can be easily checked by a quality standards approved Neon Tester.

Voltmeter and Ammeter

Three phase supply - there are three Live wires, used in factorys and apartments to power bigger loads and Motors. A 3 phase AC motor is very efficient and economical and most machines like Drills and Lathes are powered by AC Motors. 3 phase supply becomes essential for industry.

The voltage is transmitted and supplied to houses at a high level in comparison to low level of batteries. This High Voltage is not safe but Inevitable, as transmitting at lower voltage means greater current carrying requirements of wires and connectors. That leads to more copper or aluminum usage, more wastage of power due to I2R.

Earthing has to be good, use a Earth Leakage Trip Device. If earth wire gets snapped outside and some appliance is leaking, the metal clad appliances may give shock. Even if no appliance is leaking, the current thru y-capacitors of EMI Filters in Electronic Gadgets like computers are enough to make your Neon tester glow.

The Circuits related to Mains Power
delabs Technologies

Sunday, February 02, 2020

Analog Op-Amp Circuits

Operational Amplifiers - With a few Op-Amps and a regulated Power supply, many Instrumentation and Process control equipment can be designed. The Human Brain understands Numbers, Quantity and it regulation very well ! On the right you can see a analog controller based on opamps and discrete devices. A Heater, Fan and Motor is regulated, controlled and timed for a process.

Analog Op-Amp Circuits

Analog is about numbers, the circuits can be understood and designed mathematically or empirically. Designing and Building a True RMS Rectifier with Op-Amps, will help a designer digest many Op-Amp capabilities.

Analog Op-Amp Circuits

Things you ought to know about Op-Amps -

OpAmp part numbers from various semiconductor companies are designed for both General purpose and special applications. Some have to be cost-effective for consumer low-cost equipment, while others may be advanced in specs, closing in on an ideal Op-Amp.
Instrumentation opamps are used for accurate and low drift applications. These Op-Amps have stringent specifications and are used in the fields like Aerospace or Medical Electronics. A pre-amplifier for an FM Radio may need to be low-priced. Test Measurement needs Op-Amps which have near ideal specs in the area of measurement or application. CMOS low-power devices are used when designs are made for portable gadgets.
  • Outputs cannot be Loaded beyond the drive capacities, Note Resistors and Output Load.
  • Inputs draw a small bias current and will load the signal sources, compensate design.
  • Op-Ams AF-RF or Switching performance study with Slew rate and Bandwidth.
  • Power consumption of some Op-Amps are more and some very less, choose wisely.
  • Look for Standard Pin-Outs, Price, Popularity and study Abs. Max, AC and DC Specs.
  • Use Packages with multiple Op-Amps like LM324 to save board space and assembly time.
  • Op-Amps and its 1% MFR resistors should have a separate supply and far from hot parts.
  • Ultra Low Offset Voltage is required, when you wish to amplify a DC level of say 500uV.
  • Guard rings to be used for High impedance inputs and EMI-RFI Shielding for AF Amplifiers.
  • Glass epoxy PCB, clean surface, Pins and Tracks protected from Moisture and Chemicals.
  • Avoid Ground Loops, Have regulated Low ripple Power supplies. Dynamic Isolation.
delabs Technologies

Process Control Circuits for Automation

These are the circuits and boards of a Mini Temperature Transmitter for a Platinum hundred ohms temperature Sensor.

Industrial Process Control Circuits

Analog Design in Process Control is seen at the Sensor Signal Conditioning Stage. Controllers also use Opamps for Analog Computation Tasks. These are Real Time in the Truest Sense.

Process Control Circuits for Automation

A closed loop controller is the heart of an Industrial Automation System. Right from an On-Off Hysteresis Controller to a Auto Tune PID Controller, we find solutions of different complexities. Each solution might suit a particular system; depending on the requirements of Ease-of-use, Cost and Process Type.

Circuits in process control
Even today, the controllers at every stage of evolution, from the thermostat to Auto-Tune, are used in many countries, for many different industrial applications. No solution above is obsolete! The developing Countries still use electro-mechanical or semi-automatic means for control in some areas. and Process Type.

Closed Loop Control Systems

A Closed Loop Control System is the most important aspect of Maintenance, Regulation and Stability in any Live Process. Nature itself is self regulated in an intricate fashion, a keen observer can notice the subtle controls. In Human Created Industrial systems we have Process control as a complex science. We can start by understanding a Simple One.

Process Control Application Notes

When you fill a Bucket with water, You keep an eye on the Level of water, as you open the Analog Tap, which is an equivalent of a Motor operated Valve. Your Eye is an advanced Optical Sensor, which is able to sense the level by the computation in the brain, which in turn operates the muscles of your hand, thru the nervous system. The hand along with the Water Tap is is the Actuator. As the water fills up close to the top, you start reduction of the water flow and keep observing, then as it tops up, you tweak the tap to a trickle. When it reaches the limit you shut off the tap.

Closed Loop Control Systems

While you are half way filling the bucket, what happens if you take a short nap, or a friend comes by and you are get absorbed in conversation, the water overflows and goes waste. Then someone raises an alarm after the Runaway process happens. This is of minor consequence, but it is not so in the case of Temperature, Pressure and also many common systems like the driving of an Automobile. Remember the gears, brakes, accelerator to control and steer the car to the correct destination, a Runaway Process causes an accident.

Friday, January 03, 2020

Happy New Year - 2016 year of IoT

Happy New Year - 2016 - "Things to Make and Do" - delabs is recycling old greetings for 2020 as a part of our Green Initiative and cost cutting with low Carbon Footprint.

Only one important Message for 2020 - Save the Amazon Rain Forest

IoT - Internet of Things; WSN - Wireless Sensor Networks; M2M - Machine to Machine Data Communication; COR - Collaborative Online Robotics. 

Happy New Year - 2016 year of IoT

All these only mean Wireless Networked Intelligent Embedded Systems. They could be machines, appliance, robot or gadget. The brain is both on the device and in the Clouds.

Internet and Intranet of Things - IoT

When Intelligent Devices (embedded systems) are privately and securely networked, it is called the Intranet of Things. This is like a Home-Office-Business private closed Cloud. This is ideal for Home and Infrastructure Automation and even Big Business or SMB Automation........

A Practical 2018 Engineer

This was the New year greetings of 2018, the same holds good for 2020. 

Making Simple, Safe, Sensible and Sturdy Electronic Products should be the aim of any Electronic Engineer. A prototype should be developed to become a Cost effective Solution.

A Practical 2018 Engineer

Never ship Beta products or sell them at High Prices. New products if not tested and developed completely should be marked Beta and Sold at lower prices. When a manufacturer is on "The Rising Edge of the Learning Curve" (delabs phrase 1998) for a product line, he has to sell products marked beta at lower price or wait till the development is mature. I have learnt this from my own blunders.

In Software Beta markings are clear, even in Webapps they mention. Hardware Industrial products are never sold in beta state. Then the Gadgets boom led to many beta products being sold to consumers at regular prices. This should be avoided to protect the brand name and the reputation of that business segment itself.

Computer Data Interface - delabs

The PC is now an economic and common equipment at home or office. Due to Open source and GNU Linux, many professional programs and environments are easily accessible. To interface it to the real world is a step in learning Automation and Robotics.

Computer Data Interface - delabs

Computer Data Interface - delabs

In Automation we have both Industrial and Home. You can start with home automation, as industrial automation is more complex. But in Home Automation, Safety First should be emphasized, Any neglect in care of electrical hazards will neutralize any advantage of Home Automation.

Printer Port

Do not apply voltage above 5V to any pin of printer port, ensure earthing is good, use opto couplers for inputs and outputs if you are not sure. wrong use will damage motherboard, these circuits should be used only if your basics are very sound.

delabs Technologies 16:16 30-Mar-07

Analog Interface for PC Ports.
Control Interface to PC Ports.