Lenovo Miix 2.8 and the power source

More research here…

Earlier i posted about the 5V source next to the micro USB port. Today i found out that the 5V source is active as soon the OTG adapter is connected even if the Lenovo is powered of. So if connected to the OTG cable the Huawei E3331 is still active even if the Lenovo is powered off. Additional the 5V Pins I figured out on the Motherboard are powered toghether with the OTG source with 5 Volts. There is so far no external power source connected. This is weird.

The internal 3.3V source switches off when the lenovo is shut down. So to prevent the modem sucking off the battery i have two options.

Buying a step up converter that makes out of the 3.3v from the sensor connector a 5V source. Second option is to connect a small relay or IC from the sensor source to switch a permanent 5V source from the OTG USB source. Research going on but the options increase in further research.

Schreibe einen Kommentar

Deine E-Mail-Adresse wird nicht veröffentlicht. Erforderliche Felder sind mit * markiert.