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.
Archive for the ‘Electronic Design’ Category:
2024-03-24 Signal Distortion From High-K Ceramic Capacitors
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/
2024-03-15 Ferranti Argus “Hearing Aid” Computer
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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2024-03-08 FWBR Ripple Calculator Online
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
2024-02-27 MOSFET Driver
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.
2024-02-21 Website for Electronics – Very Comprehensive
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#
2024-02-17 BJT, FET Curve Tracer
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#
2023-12-05 1500 pF Capacitors “Age Down” In Value – Out Of Tolerance?
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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2023-11-14 Amsec, Gary Lorenz, John Darjany – history of campus card
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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2023-11-06 Reproduction Antique Radio Tubes and sets
I’ve been discussing the restoration of a hundred y.o. radio, and I thought about the retro light bulbs that look like incandescents but use LED filaments. Someone should make some old tubes that are actually using LEDs that look like the filaments, but just for decorative purposes. The glass envelope would look like the tube;
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