Tip: It is advisable to disconnect the diode, because it discharges a Lost 2 off the batteries. (Be careful when opening: under the name plate is a screw). Thereafter, the switch actually has no sense ...
Tip 6V> 5V: To reduce the excessive voltage when using 1.5V batteries, you can work with 2 old plus 2 new batteries (clear anyway ...)
Tip: If any USB devices behave unexpectedly with Mini-B 5-pin socket for plugging in the adapter: connect the mini-B 5-pin connector pin 4 to pin 5 (GND). (Type A: mass (OTG device works as a host), s [...]..