bq21040 Li-poly battery charger, Solar Cells and USB connector

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Hi All

 

I am planning to use the bq21040 as it has a wide voltage input from 4.5V to 28V.

 

Ideally, Vin will always be 5V, but there could be a possibility that Vin be solar cells rated between 12v to 24V.

 

The PCB have a USB connector connected to the bq21040.

 

Are there any confederation to keep in mind when Solar panel is connected to the micro USB connector using a custom cable and outputting 12V-24V?

 

The bq21040 will be configured to output 500mA to 800mA. 

 

Please note , the USB will not be connected to any device such as a PC, when connected to a solar panel.

 

Thanks

 

 

 

 

Thanks

Regards

DJ

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djoshi wrote:
I am planning to use the bq21040

That's a TI (Texas Instruments) product - nothing to do with Atmel or Microchip.

 

(in fact, Microchip do some charger chips - so it's actually a competitor product!)

 

For documentation & support with TI products, you need to go to the TI website!

 

http://www.ti.com/product/BQ21040 - note 'Technical documents' and 'Support and training' ...

 

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djoshi wrote:

Are there any confederation to keep in mind when Solar panel is connected to the micro USB connector using a custom cable and outputting 12V-24V?
 

We know what happened to the Confederates. Just ask General Lee.
You would want to ensure the input voltage is limited to less than 28 volts by using something like a zener based circuit that disconnects the input in case of overvoltage.

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The problem with using a standard connector in non-standard ways is what happens if someone thinks its just a USB connector and plugs it into something that can not take 24v!!!

I would suggest providing a separate solar panel input connector of a unique type rather then trying to re-use the USB connector! 

 

Jim

 

Click Link: Get Free Stock: Retire early!

share.robinhood.com/jamesc3274

 

 

 

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The problem with using a standard connector in non-standard ways is what happens if someone thinks its just a USB connector and plugs it into something that can not take 24v!!!

I would suggest providing a separate solar panel input connector of a unique type rather then trying to re-use the USB connector! 

+24!

"Experience is what enables you to recognise a mistake the second time you make it."

"Good judgement comes from experience.  Experience comes from bad judgement."

"Wisdom is always wont to arrive late, and to be a little approximate on first possession."

"When you hear hoofbeats, think horses, not unicorns."

"Fast.  Cheap.  Good.  Pick two."

"Read a lot.  Write a lot."

"We see a lot of arses on handlebars around here." - [J Ekdahl]

 

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ki0bk wrote:
... if (sic?) someone thinks its just a USB connector

Murphy's law clearly states that there is no "if" about it ...

 

surprise

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillatorhttps://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...