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Everything posted by HarryA

  1. You could use a microprocessor that has a a/d (analog to digital) converter. Use an op amp (operational amplifier) to increase 20mV signal for the a/d converter get reasonable results.
  2. I prototyped a couple of passive notch filter circuits including the one Tony posted. But neither were very good; two broad. If I can find an inductor between 150 to 200 mh I will try a parallel resonant band stop filter. This site maybe helpful: 8 Ways Of Resolving The Electric Guitar Feedback Problem
  3. What you need is a notch filter to remove only a narrow band of unwanted frequencies . There are pedal notch filters on the market but they are pricey. Search on "guitar notch filter pedal". Also see:: https://lambdageeks.com/notch-filter/#:~:text=A notch filter%2C also known as a frequency,while allowing other frequencies to pass through unaffected. About half way down the page he covers guitar pedals. If you wish to make one perhaps I could help you with it.
  4. It looks good to me. I would go with it. Are you building something interesting?
  5. Why not read books that interest you? For example:: Digital Design and Computer Architecture
  6. Perhaps you could convert the alternator output directly to dc without a transformer to 300vdc (or about) and use a 127-350 dc to 24 v dc dc/dc converter to get 24 volts. See: DC/DC converter 250V to 24V, 960W
  7. I do not see the connections to relay's NC contacts for each LED. The red LED most get its current through the NC contacts of the Green LED's relay. And the green LED must get its current through the NC contacts of the red LED's relay. Thus when one relay is active the other LED can not receive current through the the now open NC contacts.
  8. Hello, I am not very knowledgeable on wifi routers so I can not offer much help. This web site maybe helpful:Improve Your Wi-Fi Speed in 10 Simple Steps On my Frontier router if you type into the browser a certain number/code it brings up a rather sophisticated user interface which maybe helpful to you if you can find the code for your router.
  9. Perhaps a voltage comparator? See: Comparator You could use the 12 volts to trigger a relay that supplies a voltage to the timer? The relay should require more than 10 volts to trigger the relay to avoid the rewind? It is not clear where the 0.0009 volt and 0.1 volt signal comes from.
  10. When a post is made the forum software often displays key technical words in the post description. This would suggest that one could use that software to detect post that are legitimate from others. Of course the the devil is in the details. Invision's Zendesk maybe open to support on something like this as it would also be to their benefit. When I had a forum (Simple Machine's software) I spent a lot of time mutilating the software to get what I wanted.
  11. Practical Electronics for Inventors is a good book. Used copies are available. An online lab that is informative; you can download the pdf files from: Hunter College Lots of free info on Youtube.com
  12. First off one can not read the text on the second IC. They claim fake ICs come in two types; those that are commercial grade and sold as military grade. And those that are used from discarded equipment. The latter type may well have the correct text on them. I gather they do not manufacture fake ICs as they are too inexpensive to be bothered with.
  13. You need to supply schematic diagrams for the two circuits. If you need help with creating schematics ask.
  14. The Mega 2560 has 54 digital I/O pins plus 16 analog pins for a total of 70. You lose 2 pins for the display for either the PC display or LCD. You can have speech on the PC for free. You may need a larger LCD for numerous pins. Mapping the Mega pin numbers to the cable pin numbers would have to be predetermined. Some connectors use alpha characters (A - Z) I gather.
  15. If it interest you, I could program the micro-controller for you. That would give you an introduction to micro-controllers. The micro-controller is about 21$, a LCD about 13$, You would need a 9 volt battery, a battery connector, a battery to micro_controller connector, and a switch also. An assortment of colored wire would be helpful. Plus a plastic or metal box to pack it all into. If you are checking your cables near a computer you could uses the computer as a simple display device instead of the LCD. LCD : https://www.amazon.com/SunFounder-Serial-Module-Arduino-Mega2560/dp/B01GPUMP9C/ref=sr_1_1_sspa?adgrpid=1335907194272933 Micro-controller: https://www.amazon.com/ELEGOO-ATmega2560-ATMEGA16U2-Arduino-Compliant/dp/B01H4ZDYCE/ref=sr_1_2_sspa?crid=1L06F0IP302BX&keywords=Arduino+R3+Mega2560&qid=1684882151 wire: https://www.amazon.com/TUOFENG-Hookup-Wires-6-Different-Colored/dp/B07TX6BX47/ref=sr_1_3?keywords=colored+wire+spool&link_code=qs&qid=1684885902&sourceid=Mozilla-search&sr=8-3
  16. You could use an Arduino Mega 2560 as it has enough digital input/output pins for your 28 connections. Other micro-controllers may work but I only know the Arduino controllers. Do you need more than a simple one line display? "Yup pin 13 is okay"
  17. The D13005MD relates to the 3DD13005MD if that is any help. One would want to compare the two data sheets. It is not very likely one would have such a high power and high voltage transistor in ones stock. see: https://www.amazon.com/Generic-10PCS-D13005MD-3DD13005MD-TO220/dp/B0BRV663LX/ref=sr_1_37?keywords=d13005md&link_code=qs&qid=1684517602&sourceid=Mozilla-search&sr=8-37
  18. No, just simply add a capacitor to the AOUT terminal ahead of the speaker from your board. Can you trace pin 5 of the LM386 directly to the AOUT terminal ? There may or may not be a small capacitor and resistor connected to pin 5 also. UPDATE: It look like the board already has an output capacitor. The yellow 227C is a 220 microfarad capacitor. So you do not need to add one. see: https://www.ebay.com/itm/391354402991?mkevt=1&mkcid=1&mkrid=711-53200-19255-0&campid=5338766894&toolid=20006& Just connect your speaker to the output terminals.
  19. It looks like the unit you have is designed to work with a high impedance load like the input to the Arduino. Typically for a LM386 driving a 8 ohm speaker a 220 to 250 microfarad capacitor is used with the negative lead to the speaker. Try adding one to your unit. see the circuits here: https://www.ti.com/lit/ds/symlink/lm386.pdf?ts=1684218564218&ref_url=https%3A%2F%2Fwww.ti.com%2Fproduct%2FLM386
  20. Perhaps you could get information from dioo via email. https://www.dioo.com/#/ProductsDetail?id=889
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