Author Topic: Charging conundrum  (Read 805 times)

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Offline rthorntnTopic starter

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Charging conundrum
« on: October 10, 2019, 11:42:16 pm »
Hi,

I'm planning to have a bright LED that runs from battery, I also want a Adafruit Feather M0 WiFi to power from the same battery (unless USB is plugged in) and use the Feather charge circuit to to charge said battery, so I'm pretty sere I need to disconnect the LED when charging, what would be the circuit to do this, a relay, is there anything available off the shelf?

Thanks for looking.

Cheers
Richard
 

Offline andy3055

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Re: Charging conundrum
« Reply #1 on: October 11, 2019, 01:21:29 am »
Not sure about all the details of the equipment you are dealing with. Could you use a simple 2-way switch on the +ve lead?
 
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Offline rthorntnTopic starter

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Re: Charging conundrum
« Reply #2 on: October 11, 2019, 06:10:22 am »
Thanks, it's one of those Cree LED's on a PCB with a driver PCB from AliExpress.

When charging I would want to disconnect the LED automatically.

From here: https://learn.adafruit.com/adafruit-feather-m0-wifi-atwinc1500/

"We also tied the battery through a divider to an analog pin, so you can measure and monitor the battery voltage to detect when you need a recharge."

I wonder if that helps?
« Last Edit: October 11, 2019, 06:58:32 am by rthorntn »
 

Offline JackJones

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Re: Charging conundrum
« Reply #3 on: October 11, 2019, 07:23:19 am »
You don't have to disconnect the LED while charging. You could make a load sharing circuit, they are quite simple. Here's an example:

« Last Edit: October 11, 2019, 07:27:10 am by JackJones »
 
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Offline rthorntnTopic starter

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Re: Charging conundrum
« Reply #4 on: October 11, 2019, 08:56:08 am »
Thanks, the Feather board has a MCP73831/2 onboard, does that make a difference?

The battery is primarily to run the LED lamp but it should also run the Feather when there is no USB connected, when USB is connected the feather should charge the battery, come to think of it having the lamp run while charging will completely negate the charge current, the lamp is 1W.
« Last Edit: October 11, 2019, 08:58:14 am by rthorntn »
 


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