Hiya, first post and all very exciting. Found the forum via google image search a few months back. I do know some electronics but there is some glaring holes in my fundamental knowledge. I've sort of picked up my knowledge from reading datasheets, 'patching' things together and hacking. Now on to business I hope.
Help! My brain has just gone jelly on me...
I'm trying to build an ON/OFF/ON switch that is triggered by +/- voltage. So when the supply voltage is at rest (0v) the switch is OFF and triggers no relays, at +5v one of the ONs is on it triggers one relay and when it' at -5V the other ON is on and it triggers the other relay. See picture below if I'm talking greek...
**broken link removed**
I thought I could use just diodes, but diodes work on current not voltage... opps.
Then I thought about a using NPN/PNP transistors to differentiate between the positive and the negative, or even use two VREGs to trigger each relay; but my brain couldn't get around and that's when my head became a jello mold.
Now if it helps there is a common/ground line and a 5v rail that can be used it needed. Also yes this could be none very easily with a PIC/AVR/etc, I'm looking for a vaguely solid state solution using a handful of parts.... unless it can't be done and that's why what ever is running out by ears now is raspberry flavored.
Many thanks,
Stu
P.S. Bonus points if you work out what I'm trying to hack
Help! My brain has just gone jelly on me...
I'm trying to build an ON/OFF/ON switch that is triggered by +/- voltage. So when the supply voltage is at rest (0v) the switch is OFF and triggers no relays, at +5v one of the ONs is on it triggers one relay and when it' at -5V the other ON is on and it triggers the other relay. See picture below if I'm talking greek...
**broken link removed**
I thought I could use just diodes, but diodes work on current not voltage... opps.
Then I thought about a using NPN/PNP transistors to differentiate between the positive and the negative, or even use two VREGs to trigger each relay; but my brain couldn't get around and that's when my head became a jello mold.
Now if it helps there is a common/ground line and a 5v rail that can be used it needed. Also yes this could be none very easily with a PIC/AVR/etc, I'm looking for a vaguely solid state solution using a handful of parts.... unless it can't be done and that's why what ever is running out by ears now is raspberry flavored.
Many thanks,
Stu
P.S. Bonus points if you work out what I'm trying to hack
