FX Sound Board Power Supply

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adam0102
 
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FX Sound Board Power Supply

Post by adam0102 »

I designed a Montessori material I call the "sound box" using the FX Sound Board (https://adamgerhardstein.com/portfolio/sound-box/). I'm considering some redesigns. One thing I'd like to change is the power supply. I need a rechargeable battery that will supply sufficient power and hopefully not drain too quickly (the power bank I used needed to be charged everyday). Also, I need the power mechanism to be very safe. I anticipate some teachers may plug the device in using a USB wall adapter (like a cell phone charger) despite warnings to not leave it plugged in. What would you recommend as the safest and best power supply? Thank you.

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adafruit_support_bill
 
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Re: FX Sound Board Power Supply

Post by adafruit_support_bill »

Powerbank type battery packs are available with a variety of battery capacities. You could just go with a larger one.

You could make your own powerbank type system using a high-capacity battery and one of our PowerBoost boards:
https://www.adafruit.com/product/5035
https://www.adafruit.com/product/2465

Or a somewhat more efficient solution would be eliminate the voltage boost and power the board directly from the LiPo cell with a charger board.
https://www.adafruit.com/product/5035
https://www.adafruit.com/product/4755

In any case, the charge controller will stop the charge cycle when the battery is full, so there is no danger to leaving it plugged in.

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adam0102
 
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Re: FX Sound Board Power Supply

Post by adam0102 »

Thank you! On the product page it says you can use the LiPoy backpack setup: https://www.adafruit.com/product/2124

What sort of battery life would that allow?

Also, one issue I had with my creation was that some battery packs go dormant if there isn't a large draw from them. Since the sound board has a minimum ongoing draw if the buttons weren't pressed regularly, the battery packs would shut down and not work when the buttons were pressed. So I had to buy a low current lithium ion power bank. Is that a problem with the setups I could make using your products?

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adafruit_support_bill
 
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Re: FX Sound Board Power Supply

Post by adafruit_support_bill »

You can use the LiPoly backpack, but the charge rate is very slow and best suited to smaller capacity cells. At the maximum 500mA rate, it would take at least 20 hours to charge a 10Ah cell. For high capacity cells, it is best to use a charger with a higher charge rate - such as the ones I suggested above. The bq24074 charger has a maximum charge rate of 1.5A. So it could charge the 10Ah cell in around 7 or 8 hours.

Most PowerBank type products are designed primarily for charging phones. They assume that when the current draw drops below some threshold that the charge is complete, so they shut down to conserve power. Our chargers and boost converters do not have that feature. They will continue to supply power at low current levels.

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adam0102
 
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Re: FX Sound Board Power Supply

Post by adam0102 »

One more question - which of these charger/battery combinations would allow me to plug-in to the sound board with a cord to both transfer files to the sound board and charge the battery? I'd like to install a round panel mount (https://www.adafruit.com/product/4217) on the outside of the box and connect it directly to the sound board. I don't want to have to open up the box and change the connection to charge the battery. Thanks

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adafruit_support_bill
 
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Re: FX Sound Board Power Supply

Post by adafruit_support_bill »

You can do that with any of the charger options, but you would need to make a custom cable for it. You would connect GND and VBUS from the panel mount jack to the charger, then from the load outputs of the charger to the Fx board. The data lines: D+ and D- would go straight through from the panel jack to the Fx.

This guide shows how to do it with a PowerBoost 500 C. But the same approach will work for the BQ24074 or the PowerBoost 1000 C. https://learn.adafruit.com/booster-cable

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adafruit_support_bill
 
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Re: FX Sound Board Power Supply

Post by adafruit_support_bill »

Actually the BQ24074 makes like a little bit easier. It has breakouts for the D+ and D- next to the USB jack. (Labeled on the back of the board).

Image

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