delabs Circuits

Showing posts with label Test-Measurement. Show all posts
Showing posts with label Test-Measurement. Show all posts

Wednesday, May 03, 2017

Test Measurement and Test jigs

Test Tools are needed for Troubleshooting and Repairing Electronic Gadgets, Equipment, Electrical Panels and Machines. Precision Instruments are required for calibration of field and machine control electronics. These are also required by the R&D engineer for design and development of new products and trying out new concepts.

Test and Measurement

Test Measurement and Test jigs - delabs

In Production testing, Production Engineering, Quality Assurance QA-QC etc. You need to build Test Jigs, Configure Automated Testing depending on the size of project or budget allocated; yet it has to be made flexible, scalable and modular. These require instruments or blocks that can be adapted and reconfigured or even interface with a computing network for automated testing, reporting and analysis.

Special Electronics come with every tool or gadget these days, A Slide calipers has a LCD display, Digital Readouts on mechanical instruments can help measure even sub-microns easily. Analytical and Chemical Instrumentation is another specialized niche. Then we have medical instrumentation which is more demanding in quality and requires sensors that are small, very sensitive and safe.
Instrumentation goes into all these and beyond. The day we find water on mars, It is only because of a precision instrument at the helm of things.

These are basic measuring circuits you can build for your home lab. I have documented a lab DMM i had built for my use many years ago. the circuits may have errors, build it only if you understand.

Sunday, February 12, 2017

Tektronix Test and Measurement Equipment

Tektronix electronic test, measurement and monitoring equipment. Tektronix, Inc. is a United States corporation best known for its test and measurement equipment such as oscilloscopes, logic analyzers, and video and mobile test protocol equipment. Tek is the nickname by which Tektronix is known to its employees, customers, and neighbors.

Tektronix: Applications XYZs of Oscilloscopes

Oscilloscopes are indispensable tools for anyone designing, manufacturing or repairing electronic equipment. In today's fast-paced world, engineers need the best tools available to solve their measurement challenges quickly and accurately.

Tektronix Test and Measurement Equipment
MSO/DPO Series Mixed Signal Oscilloscope Virtual Product Demo

The company traces its roots to the electronics revolution that immediately followed World War II. The company's founders C. Howard Vollum and Melvin J. "Jack" Murdock invented the world's first triggered oscilloscope in 1946, a significant technological breakthrough. Tektronix, Inc. - Wikipedia

Additional Reading
Tektronix Oscilloscopes Museum

This site contains photos, specs, material and stories about tube built Tektronix oscilloscopes up to the late 60´s. The reasons of outstanding quality and inspired engineering of these classic scopes formed the basis of the worldwide reputation of Tektronix.

Thursday, April 16, 2015

Oscilloscopes in Test Measurement

The usefulness of an oscilloscope is not limited to the world of electronics. With the proper transducer, an oscilloscope can measure all kinds of phenomena.

Type 465 Tektronix oscilloscope

Type 465 Tektronix oscilloscope. This was a popular analog oscilloscope, portable, and is a representative example. - XYZs of Oscilloscopes - Tektronix

Introduction to Oscilloscope - The single most important diagnostic tool used by experimental physicists is the oscilloscope. Certainly all scientists and engineers should be familiar with this common instrument, shown in the Fig. 1. An oscilloscope (scope for short) can be used to "see" an electrical signal by displaying a replica of a voltage signal as a function of time.

Introduction to Oscilloscope
Oscilloscope - Wikipedia

Oscilloscopes are used to observe the change of an electrical signal over time, such that voltage and time describe a shape which is continuously graphed against a calibrated scale. The observed waveform can be analyzed for such properties as amplitude, frequency, rise time, time interval, distortion and others.

Tektronix Reference Materials

There are many older Tektronix instruments that, with a little care and restoration, are just as useful as the latest and greatest. Knowing what you have or need, and how to use it, are often more important than having the "very latest".

Oscilloscope at Willamson Labs

As important as knowing what is going on inside, is knowing how to make effective measurements using an integral part of the oscilloscope: the Scope Probes. The probe and how it is used, can make or break the usefulness of the oscilloscope.

Basic Function of an Oscilloscope

Interactive Demo - The oscilloscope is an electronic instrument widely used in making electrical measurements. The main component of the oscilloscope is the cathode ray tube (CRT). The CRT is a vacuum tube in which electrons are accelerated and deflected under the influence of electric field.

Sunday, March 15, 2015

National Instruments - Test and Measurement

For the past 30 years, National Instruments has been a technology pioneer and leader in virtual instrumentation - a revolutionary concept that has changed the way engineers and scientists in industry, government, and academia approach measurement and automation.

LabVIEW, Data Acquisition, Modular Instruments, PXI, Programmable Automation Controllers.
Here is a page from an old NI Catalog. RS-232 Tutorial of NI. drag-drop image to read.

National Instruments - Test and Measurement

One which is useful for beginners is the LabVIEW Student Edition - LabVIEW easily connects to any device be it hardware or outside applications like Microsoft Excel. You can depend on this seamless development experience as you write your program.

Wednesday, January 21, 2009

Instrumentation and Automation - 02

In Test and Measurement and Industrial Process Control a common factor is instrumentation. The measuring aspect is common to both. T&M instruments are used in Testing, Research,Automated Testing, Troubleshooting and Servicing.

Instrumentation and Automation - 02

Process control Instruments are used in Production Lines made of Machines in a Factory. It could be Counters and Timers used for Textile or Steel Industry. It can also be Temperature and Pressure Controllers used in Oil Refining or Food Processing.

So you see a difference. We have handheld Test Instruments like DMM and Scope and We have Handheld Instruments for Gas Monitoring or Humidity too. In automated testings we have rack mount test instruments. In Control panels we have Rail Mount carrying DIN standard Instruments.
  • On-Off controls or level trip relays can oscillate if hysteresis dead band is very small or absent.
  • Hysteresis is like on at 300 off at 304 like in heaters or air conditioners. If you on-off at sharp 300 there is a chatter or oscillation. This is called dead-band in temperature control. In above example 304-300=4 is the dead-band.
  • LF356, TLO71 and CA3140 are FET input Op-Amps, the bias is in pA, The caps for sample hold with these opamps are low leakage ones.10uF tantalum for long time, low resolution data. Long hold times with 12 bit data (analog) use 1uF plastic multilayer and clean-IPA + coat PCB with epoxy.
  • Design the product in such a way that neither the pot terminals or pot switch is used for mains voltage, instead use the pot switch or variable resistance for signaling and the mains can be switched with Relay or Thyristor.
  • If you need a 10.00K resistor 0.1% and you only have 1% in the market, you can trim lower values to higher values by removing the paint of the resistor and scratching the black metal film till you get the desired value. (this is only for testing or prototype development, R&D, not for manufacturing).
  • 7107 and 7135 of Intersil can be tested in-circuit, check Vref for 100mV or 1V reference, then short Vin and Vref the reading should be 1000 counts for 7107 and 10000 counts for 7135. ground plane should be good, no ground loops, PCB only glass epoxy and low leakage caps to be used, then reading will be stable, use some coating on soldered PCB.
  • An electrically Noisy environment can be simulated with a hair drier, or hot air blower. Another way Looping the NC (normally closed) contacts of a 230V Electrical Contacter-Relay can make it oscillate, this makes a lot of Sound and more important is the Electrical noise rich in EMI-RFI. This helps basic testing of timers, counters, uP, uC and embedded systems as they may malfunction in noisy environment.
  • A Single Pole 12V 100mA relay in a feedback loop, with its contacts, can make a Electrical or Electromechanical Oscillator. This can test your ground loops and digital circuit decoupling caps. It simulates power spikes which may reset some counters.
  • When a Machine with many stages or even an entire production line has to be automated, a PLC system is easiest to configure. It has digital inputs for limit switches and proximity sensors, it has analog inputs for any other parameter sensor. The PLC output modules can drive Electrical Contactor circuits with 230V Signal or 4-20 mA for an AC drive. The tacho-generator voltage feedback or pulses feedback from a motor can be fed to PLC inputs too.
  • Automation is used to enhance the quality and quantity of the product, also where there is danger to operators or workers. This moves the worker up, into the maintenance and management of materials, machines and systems.
  • Industrial Automation is essential to enhance the manufacturing worker to deliver consistent, repeatable and timely delivery of products. Absence of automation makes quality and deliveries unpredictable and stresses worker on monotonous jobs. When the worker is creatively employed with his machine on automation, it is the best scenario.

Solderman Talks 1702 AD
"Over-Automation is an utopia which is incorrect. This is because if you have no workers in any factory, there are no consumers in that city. No consumers means no sales of goods, no building of houses, no buying of automobiles. All strata of People correctly employed, reasonably paid, seeds consumerism, promotes the economy and markets. Automate everything, economy grinds to an halt."

- Solderman Talks 1702 AD

Thursday, January 15, 2009

Instrumentation and Automation - 01

  • If the waveform on the scope droops then you may need to use a 10X attenuating probe or mode. this attenuator is at the tip of the probe hence better measurement possible, also very high frequency signals may be best transmitted over a 50 ohm impedance matched line to the Oscilloscope. The History of Oscilloscope, Learn more about Oscilloscope from the Innovator of the Scope as a Measuring Instrument here is XYZs of Oscilloscopes.
  • Karl Ferdinand Braun - In 1897 he built the first cathode-ray tube...oscilloscope. CRT technology is to this day used by most television sets and computer monitors. The CRT is still called the "Braun tube".
  • Test a NPN transistor, DMM in 200K range. emitter negative probe, collector positive probe, it should show open. while still holding that way press wet finger on base and collector, it may show some reading, then it is ok. for PNP swap probes polarity and do the same thing. the wet finger when pressed applies a base current in uA.
  • Testing a Mosfet - Transistor Tester - Testing Transistors - Basic Testing of Semiconductor Devices
  • The most common reason of DMM failure is when a person tries to measure 230V AC with a DMM in current or ohms mode, with the probes in the wrong sockets. Use external attenuators and shunts.
  • A DMM in diode mode or resistance mode can be used to test IR diodes, take it under 100W lamp and measure, cover the IR diode and measure you will see a response in proper polarity.
  • If you put the DMM in 2V mode and measure the voltage across a ordinary LED near a 40W lamp you will see around 200mV. Turn off 40W lamp the mV will fall near 0. Even metal-can transistors with their top ground away will become photo sensors.
  • When you measure low voltages or high resistance like 1M with a DMM your body must not be in contact with the probe tips. Body resistance is low in comparison so error in reading or loading of mV from sensor, in sensitive and high impedance ranges.
  • Do not use an oscilloscope to measure 230V directly, use a transformer, differential probe or attenuator.
  • An oscilloscope 1M probe or a DMM 10M impedance can load circuits with nano-pico amps of bias.
  • Red socket and probe for positive and black socket and probe for negative
  • Is it oscillating ?.... We cannot say, it could also be DC, you need to see if a Clock is present. use a signal tracer or a DMM freq mode, or AC measurement. or build this When you do not have a scope you can build one for the PC.
  • Polarity and Zero Cross see the last circuit it is a polarity indicator, which will tell you to swap the leads. VRS Zero Crossing detector circuit, Zero Crossing Detectors, Comparators, Discover Circuits - Zero Cross.

Testing Tools Resources


Basic Electronics
Basics of Electronics
Product Production
Work Discipline
Testing Points
Learning Electronics
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Production Notes
Prototype Fabrication
Electrical Circuits

Scots Guide Electronics
Engineering - Wikibooks
Design Lab - Jim Svoboda
DC Circuits UOG
Socratic Electronics
Blobz Guide Electric Circuits

Product Design
Product Development
Constant Current Source
Good Voltage Regulators
Insulation Resistance
Digital Insulation Tester
DN Schematic PCB 04
DN Product Design 07

Hobby Circuits
VU Meter Circuits
LED brightness control
555 Incredible Chip
Process Control
liquid level measurement
Thermocouples and RTD
Design ADC Interface uC
Thermocouple Amplifier
IA Instrumentation 02
Temperature on DMM
Optical Proximity Switch
Analog Mux - Data Acquisition

Test Measurement
Instrumentation Automation
NI Test and Measurement
DMM Digital Multi Meter
Oscilloscope in T&M
IA Automation 01
Build Instruments
Tektronix T&M Equipment
Educators Corner – Agilent

Power Electronics
UPS Background
Transformer Connections
DN Power Electronics 03
DN Power Electronics 02
Half Bridge Convertor SG3525

Interfacing Microcontrollers
Embedded Process Control
80C31 8052 Microcontroller
Microprocessors and uC
Embedded Systems Design

Good Voltage Regulators
Relays and Contactors
Potentiometers Trimpots
Prototype Boards Types
Types of Capacitors
Types of Switches
Resistors How they Work
Coils Transformers SMPS
Mains Transformers Types
DN Components Selection 05

Tutor Gadgets
Count-Up Timer
Digital Logic Gates
Electronics Tutors

Teaching Instruments
Charles Proteus Steinmetz
Muntzing a Circuit Design
Teralab Electronics projects
Historical Instruments

Tables, Charts, Videos
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Resistor Color Code
Ohms Law
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High Resistance Materials

School - Analog Design
DN Analog Basics 06
DN Op-Amps 01
TI Semiconductors