Hello all,
I've recently designed a circuit for a device I'm making that runs on this battery:
https://www.adafruit.com/product/1317
This is a 3.7-4.2 volt rechargable battery with 150mAh and is meant to be recharged at around 100mA.
It has a protection circuit, so if you over charge the device or try and drain it too much it will shut off.
Because of this, I'm thinking I can design a USB charger that is simple and just provides a constant current and I'm currently working with a LM317 voltage regulator.
Here is the circuit I'm currently troubleshooting:
the vIN comes from the USB VBUS, the 2 negative feedback resistors cause a V output of around 3.7 volts.
When i test the current leading to the battery, I'm only getting 5mA.
I know that USB's can output 100mA and even more if required so after a couple days trying to figure this out I'm realizing I'm missing something important. Anyone have any ideas? Thanks
I've recently designed a circuit for a device I'm making that runs on this battery:
https://www.adafruit.com/product/1317
This is a 3.7-4.2 volt rechargable battery with 150mAh and is meant to be recharged at around 100mA.
It has a protection circuit, so if you over charge the device or try and drain it too much it will shut off.
Because of this, I'm thinking I can design a USB charger that is simple and just provides a constant current and I'm currently working with a LM317 voltage regulator.
Here is the circuit I'm currently troubleshooting:
the vIN comes from the USB VBUS, the 2 negative feedback resistors cause a V output of around 3.7 volts.
When i test the current leading to the battery, I'm only getting 5mA.
I know that USB's can output 100mA and even more if required so after a couple days trying to figure this out I'm realizing I'm missing something important. Anyone have any ideas? Thanks