On Saturday 04 March 2006 15:29, Stuart Brorson wrote: > > Em Sex 03 Mar 2006 21:32, John Luciani escreveu:
> > > The gschem logic symbols seem to have embedded Vcc and GND connections > > > (at least the ones that I was looking at). Since I am working on a > > > board that has 3.3V and 5V logic this is a problem. A project I am planning requires three supplies. One supply from the computer's main power supply "Standby" current to power some 7474's (after I step it down... acts as a simple collection of status bits) and one or two other parts. The other two supplies come from the primary switched +5v and 12v rails, to power everything that should only be turned on when the rest of the computer is on, like the 12VDC->9VAC invertor, status LEDs, one or two pieces of 74xx logic, etc. Obviously +12v isn't a big deal, but confusing or overwriting the 5v-switched and 5v-standby supplies would lead to unpleasant side effects like loss of settings, or wasted power, etc. Nothing that would cause damage, just annoying. Personally I think power pins should be made visible, but exactly how they're shown is a matter for debate I'm sure. A separate slotted symbol might be a good idea, as long as it's clear which package each such symbol goes with. -- "Sometimes paranoia can be helpful. Usually it isn't, and when you learn that, life improves." Vanessa Dannenberg
