replace female barrel jack with female micro usb for charging

Question

I have a Sylvania bluetooth speaker and the female barrel jack is broken. i want to put a female micro usb in instead as its more convenient to charge. but i cant seem to find a pinout to do so or anything as the such. the current jack is a 3.5mm and has 3 pins on the pcb. i understand the positive and negative but the insertion detection is what im confused on. so what pins from the micro usb would i solder to the 3 from the barrel jack on the pcb ? thanks.

Gough Lui · Answer

Insertion detection basically acts as a switch to "cut out" the battery and run on external wall supply only. It's normally only used in older disposable-battery operated appliances so that one leg of the battery is switched through the barrel jack. More modern appliances, especially rechargeable ones, tend to have internal battery/power management ICs.

If you trace the PCB, you may find that one of the three legs (the switched leg) is not connected to anything. Just make sure the V+ is soldered to the pin corresponding to the tip and the GND pin is soldered to the pin corresponding to the sleeve - https://cdn.sparkfun.com/assets/a/6/c/e/3/51141da0ce395fe67e000005.jpg

The corresponding pin-out on the microUSB connector - https://www.sunrom.com/media/content/811/micro-usb-pinout.jpg

- Gough

Gough Lui · Answer

The detection pin is marked on the image above. Trace the circuit by eye or with a multimeter but if all three pins are being used then you might need to better understand the circuit to reverse engineer it.

However, you could always replace the jack with another and just buy a USB to barrel jack cable. They're not quite so common but you can find them on auction sites.

- Gough

replace female barrel jack with female micro usb for charging

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