I am building 3V3/5V source for my breadboard. The actual voltage will be selectable by the switch. I would like indication, which voltage is actually selected by lighting green LED for 5V and yellow for 3V3. Treshold for 2N7002 is like 2V, so my idea is like that:
But there is problem, that both LED would be lit on 5V, can I somehow simply cut off the yellow (3V3) LED when the green one (5V) gets lit?
Is this schema valid (maby after some resistor adjust)?
EDIT: it is just small part of testing environment, meant to anable by jumper 5V or 3V3 output on VCC (or none, if jumper missing). There will be more such device on one PCB and there will be jumper array to configure each, so I would like indicate, what is actually on which VCCxx.
Mode of operation: set jumpers, switch power on, do something, switch power off, reconfigure all the thing, set jumpers ...
It is also possible, that the jumper will be off (SW1 not connected here) and the VCC would be else not connected, or externally driven to 3V3 or 5V. Those internal sources would be on anyway (and would provide power).
So desired result is:
- VCC around 5V (say 4.5-5.5) = green led on, yellow off
- VCC around 3V3 (say 3.0-3.5) = green led of, yellow on
- VCC unconnected or around 0V (say 0-0.5) = both leds off