Hi. I made a kind of motion sensor circuit. Unfortunately when I progressed from breadboard version to etched copper board version, the sensor standby current jumped from 37 microamps to 3 milliamps!
I've included a photo of just my third circuit design and etching attempt.
There is an Arduino and servo in the circuit but both are completely powered down. I even severed the servo power connection to make sure no power was leaking.
Please help.
And the schematic?
I see some dodgy-looking solder joints - dry joints?
I have 'beep tested' all the tracks and components. The resistors don't beep but I'm guessing they won't anyway. Please remind me how to add an image?
Use the "reply" button on the bottom, attach your image as you did and publish your post, after use "modify" on your post to edit it back and add the link of the image you attached :
Ciao, Ale.
If your circuit is the same then this will not happen. You have to work out the difference between what you have now and what you had then. Don't say it is the same because it is not.
How can you be sure that the 37μA is correct?
Could there have been an intermittent connection on the solderless breadboard?
Was the circuit actually functioning at the instant you took that current measurement?
Do you have any other evidence, such as a manufacture's datasheet, or circuit analysis to suggest that 37μA is in fact the correct current?
Maybe if you posted your schematic, we could analyse your circuit and determine which current is likely to be the correct value.
My next etch solved the current issue (not sure why) and it was back to 37uA. This is PIR sensor operation plus maybe a bit of leakage around the rest of the circuit. However, then I found the my circuit didn't work properly when in full operation! To my surprise, through a 12x magnifying lens I saw pitting in the copper that my naked eye could not and the tracks seemed very thin also. Forgetting about the board in the etchant for about an hour would have caused that. I will try again!
bodkin77:
My next etch solved the current issue (not sure why) and it was back to 37uA.
Glad you got it working.
For another time, be sure to clean the board properly after soldering - IPA and a stiff brush is good. Flux residue can be conductive, and when playing with that low current, it can be a problem.
// Per.
bodkin77:
My next etch solved the current issue (not sure why) and it was back to 37uA.
Sounds like a poor etch.
Something that you cannot see perhaps?
