Keithley 2281S 20V 6A Precision Power Supply & Battery Simulator Review, Teardown & Experiments

In this episode Shahriar reviews the Keithley 2281S-20-6. This is a Dynamic Battery Simulator and Precision DC Bench Power Supply with TFT LCD display uses a model to emulate the response of a battery over its discharge cycle. Since the model can be based on the average current of the product that the battery will power, you can estimate battery life and analyze product performance over the life of the battery:

The review is organized as follows:

00:00 – Introduction.
00:35 – Instrument overview, interface, GUI, functions & design.
04:08 – Teardown, architecture, components and build quality.
10:03 – Precision power supply benefits, short-circuit hunting.
14:56 – Time-domain capabilities, pulse measurements, graphing functions, triggering.
20:59 – Battery Test capabilities, measuring super capacitors, measuring ESR, battery discharge.
26:20 – Creating a battery model during a charge cycle, battery capacity measurements.
27:29 – Creating a discharge battery model using the Keithley 2450 SMU.
29:32 – Battery Simulator function, battery models, modifying battery limits, stress testing DUT.
36:14 – Concluding remarks.​​​

TNP #16 – Teardown, Repair & Analysis of a few mm-Wave (26GHz – 40GHz) Amplifier Modules

In this episode Shahriar takes a close look at a few mm-wave amplifier modules which have failed. The amplifiers cover a few frequency ranges up to 40GHz. The measure S-Parameters reveals a serious problem with the amplifiers. The teardown of the module is presented along with microscope closeups of various devices and integrated circuits used in its construction.
A broadband amplifier is also examined with a simpler problem. A broken DC power connector is replaced which brings the unit back to life showing 18dB of gain with better than 25GHz 2dB bandwidth.​​​

TNP #15 – The Impossible Amplifier

Could I have found the greatest amplifier on April 1st?​​​

TSP #205 – Keysight FieldFox 50GHz Handheld Microwave Analyzer / RTSA Review & Experiments

In this episode Shahriar reviews the Keysight FieldFox Microwave Analyzer which is capable of both 2-port network analysis as well as spectrum analyzer with real-time capabilities. Keysight’s FieldFox portable analyzers are equipped to handle tough working environments during routine maintenance, in-depth troubleshooting, and anything in between:

This review is organized as follows:

00:00 – Introductions.
01:22 – Instrument overview, design, interfaces, built quality.
04:38 – LCD screen, remote interface, GUI usage.
05:04 – S-Parameter personality, calibration, tuner experiment, reflection phase shifter measurements, etc.
15:35 – Power Sensor personality, PA load-pull experiment, reflection power measurements.
21:12 – Spectrum analyzer personality overview, built-in synthesizer, output spectrum quality.
24:42 – mm-Wave transmitter measurement, detecting impairments, spectrum analyzer capabilities.
29:00 – I/Q analyzer personality, RF envelope versus time capabilities.
31:33 – Real-time spectrum analyzer personality, 100% POI performance.
33:23 – PathWave VSA compatibility, mm-wave constellation demodulation example.
36:32 – Noise Figure personality, Friis equation demonstration, NF uncertainty calculator.
46:50 – Concluding remarks.​​​

TNP #14 – Teardown & Analysis of a Somewhat Dangerous LiPo-Based Mini Spot Welder

In this episode Shahriar takes a look at the a battery-based spot welder which have become fairly popular recently. Due to being mass-produced, some poor corner-cutting schemes can render these devices dangerous. The teardown of a random unit is presented. After improving the safety of the unit, a sample weld is done. The maximum deliverable energy of the unit is also measured.