Analog System Lab Kit (STEM Product) - Review

Table of contents

RoadTest: Analog System Lab Kit (STEM Product)

Author: mloik

Creation date:

Evaluation Type: Development Boards & Tools

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: Velleman K8055n Usb Experiment Interface Board Kit

What were the biggest problems encountered?: There were no real problems encountered. Use of the board did require some software downloads (PSPICE), a power supply, and an oscilloscope. So students would probably not be taking these boards home with them over the weekend.

Detailed Review:

I have reviewed the ASLK Pro from Texas Instruments, developed by TI India, and manufactured by MikroElektronika (www.mikroe.com).

 

I should note that I classified this "Development Boards & Tools" above, but it would be better categorized as "STEM Learning Tools" (that was not a pull-down option.)

 

The analog board is designed to be a learning tool for EE students. The learning objective is to gain experience with the fundamentals of op-amps and related circuits in signal processing for the design of instrumentation. The creators have cleverly included several of TI’s chips as the basis of the analog circuits, which both demonstrates how the analog circuits work and how the chips can substitute for the circuits in modern designs.

What’s in the box? In addition to the analog board, there is a 101-page manual, a heavy-cardstock quick-reference schematic of the circuits on the board, a hefty supply of linear and log-linear graph paper, and a small supply of components (DuPont connectors: 10 male-male, 10 male-female, 30 female-female; two 1N4448 diodes, one 2N3906 transistor, one 2N3904 transistor, and one BS250 transistor).

 

The manual is well done. It includes an Introduction that provides an overview of the board, software required, and a description of the experimental course that can be conducted using the board. There are 14 sample experiments. In each, the student is directed to create sample circuits, simulate various operational characteristics, plot data, present data to an instructor, build the analog circuit, and measure voltages/currents to determine circuit operations. The experiments start simple and become more complex. The manual recommends PSpice or TINA for the simulations. The manual points to some online videos that were produced to facilitate student learning that should be watched before doing the lab exercises. I agree that it would be useful to watch them ahead of time, but I found Khan Academy videos on op-amps that were more helpful. Following the experiments there is an Appendix that describes the Is used in the ASLK Pro analog board, an introduction to macromodels, a short primer on how to connect a PC to a buffer amplifier circuit to use the audio card as a limited oscilloscope output (the components required to build the buffer amplifier are not included), connection diagrams, and a bibliography.

 

The experiments include:

Negative feedback amplifiers

Regenerative feedback & monostable multivibrators

Integrators & differential circuits

Analog filters

Self-tuned filters

Function generators

Phase-Lock Loops

AGC & AVC

DC-DC Converters

Low Dropout Regulators

LDO integrated circuits

Evaluating DC-DC controllers

Gain Stage Amps

Digitally programmable wave generators

 

The analog board measures 27 cm long by 22 cm wide by 0.3 cm thick (10.63 × 8.66 × 0.12 inches). It has rounded corners and rubber-like feet to avoid slipping. The components are snugly fit into the board but I could see the screw-tab power terminals coming lose after some time of use. I examined the solder points on the back side of the board with a dissecting microscope and the joints are neatly made.

The analog board is subdivided into sections. The board requires external +/- 10 V power (not included) and an external oscilloscope for measuring waveforms. The bottom portion of the board is dedicated to two each of inverting, full, and basic op-amps, and three analog multipliers. There are also two digital-to-analog converters. There are multiple resistors and capacitors for each op-amp, allowing multiple configurations and values when conducting experiments. One needs to simply move a DuPont connector to select a resistor or capacitor with a different value. Likewise, there are various inputs and settings available (via dip-switches) for the two DACs. The rest of the board includes two potentiometers, a DC-DC converter, an LDO regulator, and sockets for the diodes and transistors. Finally, there is a powered 5 row by 25 column breadboard for including additional components or for building the buffer amplifier for the oscilloscope.

 

I used an Eventek DC power supply and a Digilent Analog Discovery 2 to try out a few of the experiments. The power LEDs lit at 4 V but the op-amps require +/- 10 V. One of the nice features is that the op-amps are powered by traces within the board. I did Experiments One, Two, Four and Eight in detail. I think about half of the student’s time would be spent creating and simulating circuits, and the other half for making measurements with the ASLK PRO. Interestingly, I think Experiment One is not as easy to understand as Experiment Two. Each one takes about 1.5 hours for the hands-on board work, which would leave time in a typical 3 hour laboratory period for a short introductory lecture, discussion of simulation exercises done before class, and lots of trial and error time. This last point may be quite important when students are getting used to using the board and constructing the circuits.

I fondly recall using analog boards as an undergraduate to conduct electrical circuit analogy experiments on biological membranes. I think it was essential to use an experiential hands-on approach to learn the foundational principles of circuits. Even in today’s digital world, I still think analog boards like this one can be a very successful way to demonstrate fundamentals of electrical circuit design and operation. I gave "Software" a 5/10 because there was no software provided; one uses external oscilloscope software and PSPICE for simulations. I gave "Ease of Use" an 8/10 because the manual is a bit ambiguous about what to connect in the first lab. A short online demonstration might help here. "Price to Performance" got a 9/10 because I'm a bit concerned about how long the pins and other connectors might last in a teaching lab. Would I use this board in my class on sensors and embedded networks? Yes, particularly if the boards were provided as lab equipment by the institution. Given the retail price I found online (about $150 US), it is the cost of another textbook. Students could work through the experiential lab exercises in pairs, thus reducing institutional costs to buy these boards for their labs. Nonetheless, the ASLK PRO could be the basis of one or two companion courses on analog circuits and introduction to signal processing.

Anonymous
  • Hi DAB,

     

    Thanks. In my haste to get the review done, I did not take any screen captures of the signal vs frequency relationship. But maybe once the dust settles over the next couple of weeks I can go back and re-do that. Great idea to add those images, thanks.

     

    Best,

    Michael

  • Hi Gene,

     

    Thanks for the kind words. Sorry for the late response though. January and February are very busy times at work.

     

    I agree that analog boards are very useful for learning purposes. I look forward to the next time I teach Sensors & Networks so I can get my hands on them again.

     

    Best,

    Michael

  • Nice review.

     

    Did you conduct any frequency or noise distortion on your amplifier?

    I would have liked to see some scope captures showing signal response verses frequency to see if your design introduced any waveform distortions of frequency spectra artifacts.

     

    DAB

  • Michael,

     

    Great write-up/road test. I agree that even in today's digital world there is still a place for analog.  And I would add that a lot of digital design can be boiler plate, but good analog design is usually only accomplished through experimentation and understanding of the 'art', that must be learned.

     

    Well done!

    Gene