Idea how to make a 2 input/3 output controller

jmr061 · Post by **jmr061** » Mon Dec 05, 2005 6:29 am

I am in need of the following:

I need a controller that will take two separate inputs (A and B) and have them control 3 outputs (1,2,3). What I want is A to power 1, B to power 2 and when both A and B are active it powers 3 but not 1 or 2. Max amps in this circuit would be 1 amp.

What this is for is a 911ep revision 1 arrowstick.

If you have any ideas it would help.

Thanks

Jason

tvsjr · Post by **tvsjr** » Mon Dec 05, 2005 7:17 am

I don't know of anything off the shelf that will do what you need, but you can certainly build it with some simple 2-level logic.

F(1) = AB'
F(2) = A'B
F(3) = AB

One 7404 quad hex inverter and one 7408 quad positive-AND would be all you need.

Note that this is 5-volt logic level stuff... handling the interface/amplification is left as an exercise for the reader.

kg4ere · Post by **kg4ere** » Mon Dec 05, 2005 7:22 am

jmr061 · Post by **jmr061** » Mon Dec 05, 2005 7:41 am

Yes I am aware a custom made unit will be required, this is why I made the post.

As far as the last post that is a revision 2 arrowstick not a revision 1. Revision 1 has separate wires for left, right and center out. There are only two switches left in the switch box to control the arrow stick pattern however, hence the reason for wanting to make a custom controller.

Thanks

Jason

Post by **HumHead** » Mon Dec 05, 2005 11:31 am

OK- I'm to lazy to try to put together and post a drawing, so I'll leave it up to the reader to draw this out, but this should be easily doable with either directly with DPDT switches, or with SPST switches driving DPDT relays. For now, I'll just describe it in terms of poles, and not worry about exactly how it is acheived.

1) Tie together the common contacts on pole A of both switches / relays.

2) Tie together the common contacts on pole B of both switches / relays.

3) Assuming that the lines are B+ switched, tie B+ to the pole A NC contacts on both relays, and to the pole B NO contact on the first switch / relay. Obviously, substitute ground for B+ if you are using ground switched control.

4) Connect control line 1 to the pole A NO contact on relay/switch 1

5) Connect control line 2 to the pole A NO contact on relay/switch 2

6) Connect control line 3 to the pole B NO contact on relay/switch 2

That should do everything that you want. The only catch is that control lines 1 & 2 will be tied to each other, without any voltage present, when control 3 is active. If that is a problem, just add diodes to the lines.

Hope that helps. It should all make sense if you draw it out and look at the logic.

Long live old school relay logic!

tvsjr · Post by **tvsjr** » Mon Dec 05, 2005 12:22 pm

Ach, relay logic? Guess I'm just not as old(-school...) as some of the people around here.

EVModules · Post by **EVModules** » Sun Mar 05, 2006 9:08 pm

If your input wires show ground at rest,

place A at 85, B at 86.

Put 3a diodes between 85 & 30 and another between 86 & 30 with the band side towards 30.

1 is connected to A directly
2 is connected to B directly
3 is connected to NC or #87a

SafetyLighting · Post by **SafetyLighting** » Tue Mar 07, 2006 6:26 pm

What happens to the Traffic Director when power is applied to all three input wires?

EVModules · Post by **EVModules** » Tue Mar 07, 2006 11:12 pm

I missed the part where it's for the Traffic Director.

You could use a module made to take a one-button momentary input which switches progressively from off, A-on B-off, A-off B-on, A-on B-on. Each momentary switched input cycles thru the 4 positions and is made for the Whelen Dominator Traffic Advisor. Very handy for limited space with just 1 button required.

tvsjr · Post by **tvsjr** » Tue Mar 07, 2006 11:22 pm

EVConcepts wrote:I missed the part where it's for the Traffic Director.

You could use a module made to take a one-button momentary input which switches progressively from off, A-on B-off, A-off B-on, A-on B-on. Each momentary switched input cycles thru the 4 positions and is made for the Whelen Dominator Traffic Advisor. Very handy for limited space with just 1 button required.

And Sean would be happy to hook you up with just such a module for the low, low price of...

EVModules · Post by **EVModules** » Tue Mar 07, 2006 11:47 pm

tvsjr wrote:
EVConcepts wrote:I missed the part where it's for the Traffic Director.

You could use a module made to take a one-button momentary input which switches progressively from off, A-on B-off, A-off B-on, A-on B-on. Each momentary switched input cycles thru the 4 positions and is made for the Whelen Dominator Traffic Advisor. Very handy for limited space with just 1 button required.
And Sean would be happy to hook you up with just such a module for the low, low price of...

... Only $34! It's small & sleek. About half the size of a deck of playing cards! Someday I need to open an online store...

SafetyLighting · Post by **SafetyLighting** » Wed Mar 08, 2006 12:30 pm

No Sean, I thinkm you have forgotten the orignal problem. He needs to have one wire activated at a time. A,B,C Not A, B, A+B. That would work for the Rev 2 Version of the Traffic Director.