Digital Analog Power Junction

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.

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.   

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

• Discussion of Sequential Timer - A
• Discussion of Sequential Timer - B
• Sequential Timer Specs.
• Two Stage Sequential Timer.
• Li-Ion Battery Charger.

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.

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

• Discussion of four Channel Alarm.
• Four Channel Temperature Alarm.
• RTD Pt-100 Four Point Alarm.
• Timer and Counter Modules.

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.

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

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 Image 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 18 Years. (2018)

Read more »

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.

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.