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How can I indicate a USB charge with an LED?
I've seen some USB ports/chargers out there that have an LED that lights up when you plug the cable in. Is there a simple way to do this? I need the LED to light when the USB cable is plugged in, not when the charger is on. So I could plug in the adapter and nothing would happen, but when I drew current to charge something, the LED would light up. I can't figure out how to do it, so I'm asking you for some aid. Thanks
Discussions
5 years ago
To check the lever of more or less anything you need a comparator. essentially an OP amp.
There should be ccts around to do what you need. Search the web fro circuits.
Answer 5 years ago
I have looked far and wide for one, but still can't find anything. Do you have any idea how I could use one?
Answer 5 years ago
This helped me to understand how they work. Hope this helps !
www.dummies.com/how-to/content/electronics-components-how-to-use-an-op-amp-as-a-v.html
5 years ago
Well I have seen many RC helicopter chargers include a LED in the male end of the USB cable. You can show it has power by simply crossing the 5v and ground across a led and a resistor(100-220Ohm)
As per Charging indicator, Have you already chosen the chips you will use to charge? I would recommend checking out this Charging IC It is one commonly used in Li-po chargers, and provides the option for a status LED ( Look at the Data Sheet) Unfortunately you are limited to 500ma charging rate; hope that's enough juice !
Answer 5 years ago
I would really like about an amp to an amp and a half. I'll take a look at the chip though, thanks for the idea.
Answer 5 years ago
Then I would Second Rickharris with the OP-Amp. Good Luck !
Hope to see what your making ! :D
5 years ago
well, I guess you could use some clips to use the conductivity of the material as USB input switch. I made this image, metal dashes are in own charger
Answer 5 years ago
I was considering that, but that shows when the cable is plugged in, whether or not current is actually flowing through the cable. But thanks, I may do that anyway.
5 years ago
Where is the LED, on the USB port ?
Answer 5 years ago
The LED could be anywhere, it doesn't matter, I just need it to light up when I plug the cable in.
5 years ago
To check the lever of more or less anything you need a comparator. essentially an OP amp.
There should be ccts around to do what you need. Search the web fro circuits.