Hi Tassos -
If you can find a source for power resistors, that might help.
You could skip the 7805 altogether, and feed Vin through a dropping resistor from +12. If the resistor dropped Vin to, say, 5 volts, you would need (7V/0.15A) = 47 ohms. This resistor should be rated for at least 2 watts; 5 watts would be better.
Sometimes small incandescent bulbs can be used in this role. Something like a #47 bulb might work . Or you might find an automotive interior bulb that has the right filament resistance - you'd have to experiment a bit since the bulb ratings are given for 12V service and you would be using it at about half that voltage.
Good luck,
-hb
Hi, I'm having trouble powering the MBED using the Vin input. I use a 12 DC power source and a 7805 regulator to feed the Vin (7805 gives ~ 4.8V). The 7805 gets instantly extremely hot (MBED is pretty cool though). Using a 7808 the same happens only this time the MBED gets hot!!.
Using the USB to power the MBED (without external supply connected) everything is cool. I measured the resistance between Vin and GND on the MBED (all other MBED pins in the air) and I saw something like 1.3K? Is there some thing wrong with the MBED or have I managed to fry it up?
I've been searching the forum but haven't seen something similar (in any case if there is a similar topic I would appreciate it if someone could provide the link).
Tassos.