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Sunday, October 06, 2019

Millivolt Source with Digital Potentiometer

Here is a Millivolt Source i built for Calibration in the early days. It uses only CMOS Digital and Mixed Chips from Intersil and CD40xx Series.

Digital Potentiometer - del50003

In this Circuit, digital potentiometer, connect pushbutton switches to fast and slow with one end to +7.5V, when you hold the button down the analog voltage will ramp up-down, fast or slow, this will enable you to make a digitally controlled millivolt source or power supply.

Millivolt Source

Later i tried a unit with 8748 part of the code in my uC section. This is with Ramp-up and Ramp-down using only two buttons. This works even now, The support below is an HRC Fuse Holder made of Phenolic or Epoxy Resin. The mV Terminations are on Top.

80C39-8749 MCS-48 Examples and code

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.

Wednesday, October 02, 2019

National Semiconductor

National Semiconductor was an American semiconductor manufacturer, that specialized in analog devices and subsystems, formerly headquartered in Santa Clara, California, USA. The products of National Semiconductor included power management circuits, display drivers, audio and operational amplifiers, communication interface products and data conversion solutions.

Wiki of National Semiconductor

National's key markets included wireless handsets, displays and a variety of broad electronics markets, including medical, automotive, industrial, and test and measurement applications.

On September 23, 2011, the company formally became part of Texas Instruments as the "Silicon Valley" division.

An Exquisite Evaluation Board from National Semiconductor.  SD356EVK Evaluation Kit Board for LMH0356 SDI Reclocker

LMH0356 - NSC

The LMH0356 Serial Digital Interface (SDI) reclocker is designed to recover a clean clock from a serial digital video signal which may be contaminated by jitter and to resynchronize the input video data to the recovered clean clock. The LMH0356 SDI reclocker accepts signals conforming to standards SMPTE 259M (C), SMPTE 292M, and SMPTE 424M.

Intersil Hot Ideas 1983 Mixed CMOS Revolution

These helped me build Intelligent Instruments in the 80s. Intersil was with GE earlier, innovators of   advanced CMOS before anybody else. They made the smartest chips when the Microprocessors were being examined Skeptically by engineers. (At that time Microprocessors needed many support chips and consumed huge power only later CMOS uC came).

Intersil Hot Ideas - 1983

Intersil Hot Ideas - 1983

Today i found out that another company of that time called Datel is back, it was first a part of GE like Intersil then went to Murata now after decades it is back home.

"Datel was established in 1970 and has been a long time leader in providing high precision data acquisition components, including data converters, power supplies, DC-DC converters, and digital panel meters. "

Friday, September 20, 2019

Digital Signal Processing - DSP

When you are trying to arrive at a complex Embedded Systems and Communications solution, You will think of a DSP. Now that computers and embedded devices are used in most electronic devices, DSP is a way you can process, transform, analyze and generate fast analog data, in Real Time.

Real Time ideally is instantaneous or in sync, in tandem. Not an Zepto Second lost. But in the real world many analog inputs or result outputs can be processed a lot slower. So it is more like, How 'real time' you want, how cost-effective a real-time solution can be provided. If the analog input is slow and the system inertia is high and the user response time is limited by his persistence of vision, you need to make a system just a bit faster, even Microseconds delay may be fine. In yet another case it may be pico seconds.

Digital Signal Processing - DSP

A web page in a browser delays a few milliseconds, you will not notice; but when you talk over the phone a small delay, echo or glitch can be unpleasant.

In a weather station the wind speed, atmospheric pressure and relative humidity are measured as analog signals using special sensors. This is then converted to digital data and fed to an embedded system or computer. The computer software analyzes the data and arrives at some predictions based on past patterns. This system in its simplest form, may not be DSP, but it is the beginning of this science, the first step.

Sunday, September 15, 2019

Process Control Education - Instrumentation

A Resource of Value for Industrial Engineering. Here is an Online Textbook for learning advanced process control concepts.

The Process Control Education Web Site

The Reference includes Sample Process Control Course, Instrumentation for Process Control, WEB-Based Educational Resources for Process Control and Process Operability.

 The Process Control Education Web Site

The material above can also be found on the -Process Control, 2nd Edition, McGraw-Hill, 2000 - ISBN 0-07-039362-1 a textbook by T. Marlin.

delabs Notes - 

Industrial Automation enables Higher skill levels for workers and reduces danger of accidents too. Now the emphasis is for Energy Efficient Industrial Production, not only to save Energy Costs but as a Social Responsibility.

Industries should not pollute water bodies and the atmosphere, this brings us to new process control area of Air and Water Quality Measurement and regulation.