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RC circuit thing

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i remember doing an experiment with capacitors and resistors to make an RC circuit that would delay the turning on of an LED. ive forgotten how to make this circuit and i havent been able to recreate it by myself and after seraching google for RC circuits and similar seraches i have found nothing...little help? :)

edit: sorry i didnt mention that i got this RC thing but it takes time to turn on and off, i cant remember if there was an RC circuit which would onyl take time to turn on, not off.
 

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Hello!
I believe what you are looking for is a "Monostable Delay On" circuit using a 555 timer. Basically, when you apply power, the output is low until the calculated time has elapsed. When that has elapsed, the output will remain high.

This was off a Google search, you can search for stuff like "555 + Monostable Delay On". Here is the simple website I found that may be of help:
https://555-timer.clarkson-uk.com/operation/delay.html

And there's a nice little calculator down there for you too!
-Omar
 
no i specifically dont want to use a monostable,i would prefer to use the circuit i posted with the delay to turn off too, i probably should have mentioned that. thanks anyways tho!
 
Your circuit could be modified to turn off quickly if you turned the switch around the other way so that the common goes to the 50K.
Then connect the unused normally closed contact on the switch to 0V and connect a schottky diode across the 50K with its anode towards the cap.
 
Try this

I do a lot of them too. Use the 555 and if you want on delay just select your resistor and capacitor for the time, or use a potentiometer but dont connect pin 7 (discharge) to anything. The resistor will slowly fill the capacitor and when it gets to 2/3 the source voltage pin 3 will go low and stay low until you connect discharge. So make sure your LED positive side is connected to high because pin 3 after trigger value will go low. Is that what you needed ?
 
What I see in your diagram is Crocodile3D showing a 6V source charge via a 50K ohm resistor to the base of a transistor. That diagram will bring the LED to full bright via time, using the 555 it turns on and off and stays in that state. Hope that helped. Jim Now I see what you wanna do, how about a normally open switch I call it a "shunt" between the positive and negative of the capacitor. Use a 50K in series with the switch to turn off at the same rate it charged up. I went back and edited that..... Im just a novice myself but I learn a little more every day. Jim
 
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Hey jim,

I apreciate you working that out for me, but I posted this thread over 3 years ago and I can't even remember what I needed this for! None the less thank you for your efforts and you are right, we do learn a little more everyday, so don't consider your work wasted as you have learnt a little more from it :)
 
Thats hysterical ! I had no idea, I better start checking the dates from now on huh? Glad ya got what ya needed, I was just gonna log in and start a thread because Im "venturing" into microphone elements and how to get them to drive another type of component, any help you have is of course much appreciated. I think it has to do with the mic element charging a very small capacitor which then turns on a small transistor then a bigger component, I dunno.... Jim
 
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