Relay Logic Brain Teaser

[Gerry 13]

How is this supposed to work? As I see it (starting from rest): push the button, A comes on release the button, A stays on, B comes on B makes C come on C makes D come on D makes A go off A off makes B go off B off makes C go off C off makes D go off So the OUT is only on while the PB is pressed (plus the time for 4 relay armatures to move)

[Keith Menges 0]

You're right, Gerry. I tried to shortcut this with common pushbutton contacts. Each of the latches needs it's own pushbutton contact for this circuit to work. My bad. Keith

[speakerman 4]

Hey Keith; It just looks like you need to split up the wiring for A and C, and add one isolated N/O PB contact to activate C on the second push through an active B. The B and D circuit needs to stay linked, as the only path to D through C while the button is pushed is through an active B contact. Then the flow will be as follows: push the button, only A comes on release the button, A stays on, B comes on push the button again, B makes C come on (at this point, the button could be released and the flow would continue) B and C make D come on D makes A go off A off makes B go off B off makes C go off C off makes D go off The thing I like about this circuit is that once the button is pushed the second time, the relay chain will continue no matter how short or how long the button is held, as the seal in hand-offs ensure that last relay to go off will always be D. Cheers! Speakerman Edited 12 Feb 2008 by speakerman

[cHud 25]

You better hope he doesnt read this thread

[panic mode 246]

hi chakorules, how prepared is your team?

[Chris Elston 78]

Nice picture! I didn't know you helped out a team too! Here is our robot video Those of you that don't know what me and Panic are talking about it, you can watch this years game animation here: http://www.youtube.com/watch?v=yViRWaSODIc So you can understand what the robot was built for.

[arj3090 5]

Is this a DC or AC circuit? It does matter because in DC you can use diodes.

[arj3090 5]

Here is a solution that works with DC. It only uses 2 relays each with 1 NO/NC contacts and 2 diodes. The PB must have 1 set of NO/NC contacts ... Now that I look really close, I think it has a race condition when pushing the button the second time. The frustrating part is that I did this about 10 years ago with a couple automotive relays to switch a device on and off from a pulsed out. BUT, I lost the drawings! PBLightDC2004.bmp Edited 21 Feb 2008 by arj3090

[BobLfoot 301]

Hey Chako too bad you can't get robot A and robot B to work cooperatively and say A throws and B catches or better yet get the timing down so the robot catches it's own ball. This would eliminate the hunt and re-cue time and mean more laps.