HarryA

Will the first circuit here do what you want to do? Fading LED circuit. I tried it in the simulator but I have not got it to work yet; poor connection 🤨

You say: " one wanted the current to rise lowly from 5 volts to 10 volts each ten seconds," Is 5 volts off for the lamp? Also you all say: "had its light intensity decreasing to zero volts:" That statement is confusing; which is going to zero the light intensity or the applied voltage?

You can get technical support here: https://www.monolithicpower.com/en/products/ev1909-tl-00a.html

Promac TV Universal Remote Codes & Program Instructions

If you search on the internet for "Automatic electric bell using wifi "you will find numerous articles on the subject: like: https://www.youtube.com/watch?v=jkG9sUWc1CA

https://search.yahoo.com/search?p=2381BG-2-6&fr=opensearch

What does not work? The LED fade or the mp3 player? What do you wish the push button to do? A: Push the button once and the LED fades on and off until you push it again. B: The LED fades on and off while you hold the button down. Releasing it the fading LED stops.

I am not sure what you need but here is code that fades a LED up and down. It does not block your code by using Delay(), You can paste it into your Loop{} or call it as a function. You may wish to play with the int period value and the +/-5 value. Do note which i/o pins you can use with this PWM code. //use pins 3, 5, 6, 9, 10, and 11 on the UNO const int ledPin = 3; //whichevery pin you choose Do not forget the resistor! int period = 10; //how fast to fade the LED:100 = 1/10 sec. etc unsigned long time_now = 0; //have not read the time yet int brightness = 0; //start with LED off boolean IncreaseBrightness = true; //start with increasing brightness void setup() { pinMode(ledPin, OUTPUT); Serial.begin(9600); //you may have this; used here for testing } void loop() { // non-blocking delay if(millis() > time_now + period) //get current time and compare { time_now = millis(); //for next time //fade LED up or down if(IncreaseBrightness) { analogWrite(ledPin, brightness +=5 ); if(brightness >= 255) IncreaseBrightness = false; //max ouput to LED = 255 } else //must be decreasing brightness { analogWrite(ledPin, brightness -=5 ); if(brightness <= 0 ) IncreaseBrightness = true; //min ouput to LED = 0 } } //some code...testing displays values..... Serial.print("brightness "); Serial.println(brightness); }

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.

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

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.

It looks good to me. I would go with it. Are you building something interesting?

See: Introduction to PMIC - Part 1

Why not read books that interest you? For example:: Digital Design and Computer Architecture

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