In this episode Shahriar presents a meticulously prepared set of educational lab kits on Power Conversion by Texas Instruments. These kits include Buck, Boost, LDO and Buck-Boost power conversion courses complete with a beautiful set of lab instructions and PCBs. Each kit describes up to 7 different exercises which demonstrates various aspects of power conversion characterization and design challenge.
In particular the Buck Lab kit is examined. The PCB is populated with two different Buck DC-DC converters which are carefully described in the lab kit. The first experiment of the lab kit is performed which involves measuring system efficiency under various load conditions and switching frequency. The inductor current, MOSFET switching voltage and output waveform are examined on the oscilloscope.
In this episode Shahriar demonstrates the principle of operation of a purely passive Weston watt-meter manufactured in the 1950’s in Newark, NJ, USA. This watt-meter makes no use of active devices (tube or solid-state) and yet is able to measure real-power both at DC and AC.
The teardown of the unit shows the construction of two coils interacting to advance the needle on the display. One coil produces a magnetic flux proportional to the current input and the other coil produces a magnetic flux propositional to the voltage. The interaction of the flux moves the needle proportional to the total power which is the product of current and voltage. The instrument is then used in conjunction with a power supply and electronic DC load to verify its functionality.
In this episode Shahriar demonstrates the capabilities of a Waveshare 7.5-Inch tricolor e-Paper display. By combining the display with a Raspberry Pi Zero, the SPI interface of the mini-computer can be used to program and configure the e-Paper display using Python scripts. Furthermore, the Python script takes advantage of the available API of a few website to provide relevant information such as the current date, calendar, task list with due-dates as well as the current weather and weather forecast all in a clean user interface.
The complete Python code is presented and analyzed and the principle operation of the display is also presented. Do not forget to check Applied Science’s video on this topic as well. Finally, the individual pixels are examined under the microscope while the screen undergoes a refresh which demonstrated how various colors are displayed.
The complete code can be downloaded here. You can also buy the e-Paper display here and the Raspberry Pi Zero kit here. If you are interested in using an ESP WiFi module with Arduino to interface with the e-Paper display, it can be found here. You can chose any picture frame to complete the project. The Task Manager and Weather APIs can be found here and here.
In this episode Shahriar demonstrates the effort for collecting affordable components and instruments in the past year to be able to generate mm-wave frequencies in the lab. The main goal is to generate synthesized CW signals beyond 26.5GHz and to be able to analyze them on the Keysight MXA Spectrum Analyzer.
Several instruments and components are which include the HP 83752B Synthesized Sweeper, HP 83556A mm-Wave Source Modules between 26.5-40GHz and 40-60GHz using doubler and trippler architectures, HP 8349B 2.0-20GHz amplifier, HP 11970 series harmonic mixers and OML DPL313B diplexer. Combining all these instruments along with various waveguide to coax converters mm-wave generation and detection is successfully demonstrated.
Finally, a full teardown of the mm-wave source module is presented which includes the preamplifier as well the waveguide module with very interesting design architecture.
In this episode Shahriar demonstrates a full analysis of a CDM324 24GHz Doppler radar module from IC Station. Opening the module reveals a series of microwave PCB components and several active devices. A complete analysis of the module is presented. The unit is then measured and the impact of antenna impedance and power supply voltage on the output frequency is measured. The phase noise of the output signal is also measured. Using a series of servo motors, the radiation pattern of the antenna array in both azimuth and elevation is also presented.
Using the radar module the speed of a computer fan is remotely measure using an oscilloscope and FFT function.
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The Signal Path (TSP) is an electrical engineering video blog for industry professionals, students and hobbyists. TSP is a non-for-profit website dedicated to provide free education spanning a wide range of electrical engineering topics. Equipment reviews, tutorials and repair videos are posted regularly.