The modules use both the RCWL-9616 and the BISS-0001 but it seems the schematics are all labeled BISS-0001. The parts values are different. He gives some good information about them. They operate at 3.5 and 3.98 GHz – the ones I have were advertised at 5 GHz. Also he shows his own version that uses a
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The 555 timer chip has been extremely popular for over 50 years. The 555 number was assigned by Hans Kamenzind; it was not named after the Three 5k Resistors. This 1 min YouTube short explains.
A good article about signal distortion in a Butterworth low pass opamp filter using C0G and X7R MLCCs. https://www.edn.com/signal-distortion-from-high-k-ceramic-capacitors/
In the “Original Series” chapter this very interesting Wikipedia article talks about the “hearing aid computer” that used the OC-71 germanium transistors which were used in hearing aids and could go only up to 25kHz clock rate. That was quite slow – tube computers could clock at 500kHz. Later models used faster transistors and could
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This may be helpful when choosing the amount of capacitance for a certain unregulated AC power supply – the kind that uses an old fashioned transformer. It calculates one variable given the others. https://www.chipbuilder.com/full-wave-power-supply-ripple-calculator.html
The gate driver circuit shown in the screenshot uses BC547s, which are limited to less than 200 mA current. Instead, if the two transistors were BC337 or PN2222A which can easily handle over 500 mA, they could charge and discharge the gate faster, and thus reduce the dissipation in the MOSFET.
This very comprehensive electronics website has many projects with useful devices. This example project is a transistor curve tracer. Go to the index and look at the many, many links. It seems to be at the ETH in Switzerland but some of the words are in ?Thai? https://www.changpuak.ch/electronics/Curve_Tracer_advanced.php#
This very comprehensive website has a transistor and FET Curve tracer. Also a simpler curve tracer for all components. Click on box to download the schematic, etc. https://www.changpuak.ch/electronics/Curve_Tracer_advanced.php#
James Chessman gave me permission to use his comment. “””I have encountered a phenomenon called “age-down” in ceramic capacitors tested on ICT (In-Circuit Test) machines. I was working for a circuit-board manufacturer, developing new test sets. I was seeing these caps consistently read high in new tests. And, pulling them out of the circuit they
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I finally found a bit of history about Gary Lorenz. He and I were high school friends. In 1972 he and John Darjany founded a company, Amsec, to make a “campus card system” for California Polytechnic University, Pomona. In 1974, Amsec was purchased by R.D. Products. A brief history of the campus card industry This
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