charge/discharge capacitors

im doing a simple charge and discharge project with a 330v/160uF cap with a standard 5v usb power source on the mega.

when i set this up on my board it it charges the capacitor and when i press the second button the discharge the cap to light up the light for a second it doesnt do anything. i checked the cap and the light and its working.

Put a current limit in series with the LED, 270 or 330 ohm.
Make sure the LED is not installed backwards.
Connect the cap- to Gnd, and the 2nd button to the cap +.

can you show me fritz way? your cap description is a bit confusing.

If you have connected as in your picture you haven't got the 5V connected to anything.


Sorry, I don't do fritzing.

ok my bad that was a mistake on my part. but real life i connected it. ran a volt meter so power was going to the cap.

im having trouble reading schematics. i cant visualize it.

You're going to have a hard time with engineering as a career then.
Two buttons, a cap, a resistor, an LED, power, Gnd. That's a pretty simple schematic.

yea i gave up on a career. just not very good. but i thought i should learn it slowly over the years as a hobby.

Please check the picture i posted.

Has possibilities; can't see where all the wires go.


In that fritzing diagram I see no connections to ground anywhere except to the power rail, unless you made a mistake in the diagram, which would explain why it's not working.

check the most recent one....

the resister and cap is attached to ground.

The ground wire from the arduino is going to the wrong power rail on the breadboard (outer rail instead of inner rail).

The cap+ should connect to the wire that connects the 2 switches together.

The one in post #10 shows the ground attached to the topmost rail. Nothing else is connected to that rail...

Crossroads: The pin he shows as connected to the cap is electrically connected to the wire between the two switches - those switches have two pins connected to each side of the switch.

Which is another thing to look at - make sure the switches are the right way around :stuck_out_tongue:

the ground/power issue was just a mistake on the picture.

i put the cap where i think you told me but no go.

azzy what do you mean make sure the switches are the right way?

any help?



Turns was the damn breadboard that was giving out. I redid the entire schematic on a different breadboard and bam it worked the first try. i did it right i was able to press button 1 and hold it to charge it then second button to release the charge to run the led.

i even went as far as add more capacitors in parallel to extend the led light by a good 2.8 seconds. so now i got a mini capacitor bank.

so my next step is to put then in series and dump them and have my clamps observe the voltage spike.