And a quick follow up question too. What if Instead of a regular diode,
I add in another LED as my "charging" indicator. I would have to
increase the charging voltage to take into account the larger voltage
drop correct?

Thanks,

Josh Koffman

Josh Koffman wrote:
>
> Hi all. This is going to be a bit odd, but I haven't had much sleep
> lately, and I just want to make sure my thinking is correct. I am
> designing a simple continuity tester, with a rechargeable battery. I
> would like the battery to be charged through the same two terminals it
> uses to test with. Because the indicator is an LED, I can't just connect
> up a supply, because that would reverse bias the LED and cause no
> current flow. How about this design though?
>
>         -----|>|-------                 diode
>         |             |
>         |             |
>         --|<|--/\/\/\-|                 LED + resistor
>         |             |
>         |             |
>        ---            |
>       -----           |                 rechargeable battery
>         |             |
>         |             |
>         o             o                 test/recharge terminals
>
> my theory is that in regular operation, the current will go through the
> LED and light it in the event of a continuous circuit. If I apply the
> proper polarity recharge voltage to the terminals, it will reverse bias
> the LED, but forward bias the other diode, and charge the batteries.
> Question is, will it work? What diode should I use so that I might
> minimize the voltage drop?
>
> Thanks,
>
> Josh Koffman

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