TSP #21 - Tutorial and Experiments on Energy Harvesting ICs
47K views
January 3, 2013 1:44 PM
In this episode Shahriar investigates some state-of-the-art energy harvesting ICs from Linear Technology. The LTC3105 is a highly efficient 400mA Step-Up DC/DC Converter with Maximum Power Point Control and 250mV Start-Up. After exploring the IC’s internal block diagram, the evaluation board for this energy harvesting chip is presented. Various experiments, including the calculation of efficiency, maximum power delivery, start-up behavior and MPPC are presented. As a last experiment, a two stage energy harvesting setup using a solar panel and a super-capacitor capable of charging an iPhone is demonstrated.
The second IC of interest is the LTC3109 which is an Auto-Polarity, Ultralow Voltage Step-Up Converter and Power Manager Energy Harvesting chip. The block diagram and the evaluation board of this IC is presented. The ultra-low voltage capability of the circuit is demonstrated through the use of a Peltier cooler thermo-electric component to generate a 5V output voltage. As a final experiment, several ice cubes are used in conjunction with the thermo-electric generator in order to harvest enough energy to charge an iPhone for 30 seconds.
The Signal Path
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TSP #20 - Tutorial on the Theory, Design and Measurement of Nyquist Digital to Analog Converters
32.9K views
December 9, 2012 11:40 PM
In this episode, Shahriar presents the theory, design and characterization of Nyquist Digital to Analog Converters (DACs). After a brief overview of DAC operation and theory, the schematic of an 8-Bit R-2R DAC is presented. The R-2R DAC, which is driven by a dsPIC30F6014A Microchip microcontroller is capable of producing ramps and arbitrary waveforms uploaded through an RS232 interface. The static integral non-linearity (INL) and differential non-linearity (DNL) is measured by using a Rigol DM3068 Multimeter through a Matlab interface program. The dynamic performance of the DAC is characterized using an Analog Devices AD6645 105MSps 14-Bit ADC evaluation board coupled with a USB FIFO interface board. By using the ‘Visual Analog’ software, the spectrum of the DAC output as well as the signal to quantization and distortion ratio (SQNDR) is calculated. Finally, the impact of component mismatches, operational amplifier non-linearity and timing uncertainty on the INL/DNL and SQNDR (ENOB) of the DAC is examined.
TSP #19 - Teardown, Repair and Calibration of a Keithley 220 Programmable Current Source
51.5K views
November 26, 2012 12:16 PM
In this episode Shahriar investigates the cause of failure of a Keithley 220 Programmable Current Source. Despite being manufactured in the mid-1980’s, the Keithley 220 is still a very popular programmable current source. Alongside the repair efforts, the schematic of various analog, digital and power supply boards are also presented. By interpreting the failure mechanism, the fault is traced and corrected. The Keithley 220 is then calibrated and the calibration procedure of the sub-100nA range is explained. Finally, the performance of the calibrated unit is verified using a Rigol DM3068 Multimeter.
The Signal Path
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TSP #18 - Teardown and Repair of a Fluke 196B Handheld ScopeMeter
76.1K views
November 20, 2012 8:43 AM
In this episode Shahriar goes through the teardown and repair process of a Fluke 196B Handheld ScopeMeter. This unit, which has been purchased as a “dead” unit from eBay, is examined for faults. During the teardown, various PCB components, architecture and design is presented. The performance and functionality of the unit is verified with a few brief experiments. Finally, the schematic and block diagram of the Fluke 196B is explored for the finer details of its design and operation.
TSP #17 - Rigol DSA1030A-TG3 Spectrum Analyzer Review and Experiments
75.4K views
November 18, 2012 11:40 PM
In this episode Shahriar extensively reviews the Rigol DSA1030A-TG3 Spectrum Analyzer. A wide variety of experiments are performed using the Rigol spectrum analyzer to serve both as a tutorial to use the instrument and to demonstrate its capabilities. Some measurement results are also performed using other calibrated instruments to verify the accuracy of the spectrum analyzer. The Rigol DSA1030A-TG3 can be purchased directly from Rigol Inc.
The Signal Path
http://www.TheSignalPath.com
