We are building a system that needs to have 2 kinds of USB Switch: one momentary (normally closed) and another that is not momentary (like this). We are thinking about doing something like this:
where SW2 will be used as a normally closed switch, R1 will have some value just to avoid short cuircuits and M1 will be a MOSFET, not sure what (we don't really have an electronics background, it's just to complement an embedded systems course project). Before the USB female VCC we are thinking in putting a LED (perhaps). I don't know if I got the MOSFET pins right, but the idea it's this:
- If SW1 it's open, nothing goes to USB-F
- If SW1 it's closed and SW2 it's open, then we "short-wire" the VCCs
- If SW1 it's closed and SW2 it's open, then it's logic 0 in the MOSFET which will make that nothing goes to USB-F.
Now here are some questions:
- Is there any better way to do it?
- Do you see any problem with this system?
- What happens if SW1 it's open and we close SW2?
- Can SW1 and SW2 be those simple switches that only have rating of 20-50mA? I'm a little worried about that because this sources can give up to 2A and I don't know if all of those amps pass through the switches (even if the mosfet requires low power).