Arduino Pro mini (3.3V) power supply

Hey y’all,

This is my first time using this form so please excuse my ignorance.

I’m trying to power a Arduino mini pro but I’m having trouble getting it to turn on. I have a set of ac terminals and I’m using a resistor bridge and a capacitor. The reading from my oscilloscope shows that I am getting almost exactly 5v. Have any ideas?

Thanks,

-Charles

Use USB to power it up, you can plug usb in your laptop and on the other side cut it out and get Vcc and GND. You will need multimeter to determine Vcc and GND. Easiest way to power up Arduino Pro Mini.

If you have Arduino UNO or Nano then you can use its 5V & GND to power up Arduino Pro Mini.

You should power up with another source to check whether your board is working or not. If its working then clearly your bridge setup is not working correctly.

Thank you for your quick response!

The thing is is that that is all my project will have access to. It will be in an underwater pool light. I actually have turned it on and uploaded a sketch to it using my Arduino Uno as a power supply and arduino isp.

Thanks again,

-Charles

chuckdeak:
I’m trying to power a Arduino mini pro but I’m having trouble getting it to turn on. I have a set of ac terminals and I’m using a resistor bridge and a capacitor. The reading from my oscilloscope shows that I am getting almost exactly 5v. Have any ideas?

Where can I see the schematic of your setup?

Here is a simple schematic. The cap is a 100000 PF rated for 100v and the diodes are 1n4007’s

Link for photo:

https://1drv.ms/u/s!AhYNli_yeVwegaUGoi6FlakcZHbcpQ

chuckdeak:
Here is a simple schematic. The cap is a 100000 PF rated for 100v and the diodes are 1n4007’s

100000 pF would be 0.1 µF, quite useless as a reservoir capacitor.

You would want as a minimum, a 1 mF capacitor (that is, 1 millifarad, commonly referred to as 1000 µF), but this really is a poor approach to powering the Pro Mini.

You need to tell us exactly what AC voltage your underwater pool light is using and (XY problem!) what you are really attempting to do as you are almost certainly going about it the wrong way! :grinning:

Ok I believe it’s about 15v ac. I should probably figure that out. Either way I’m getting a 4.9v output. I’m thinking that the amperage I’m getting out of it is a problem seeing as it struggles to power a small led. Besides the frequency is there anything else you need?