Let’s practice brain!

More than one way.....

Me, I cheated.

[attachment]

Just don't ask what happens when a light bulb burns out....

rsdoran said:

Ifn ya have a problem with this "test" just look up or think about using 3 & 4 way light switches. This would be a roll your own example.

Click to expand...

Ron,

I want to see your solution...

Maybe, Allen, maybe

Ah--but does the voltage drop across the lamp leave enough voltage to sound the buzzer?

appears that the dastardly controllogix has corrupted Allen's thinking

Re: Maybe, Allen, maybe

Rube said:

Ah--but does the voltage drop across the lamp leave enough voltage to sound the buzzer?

Click to expand...

Sure... It's a 240V circuit, 120V 100W light and 120V 100W buzzer.

I am looking at doing it with a truth table because that would be my weak point.

I dont have anything to draw it with at this time but here is one solution in written form.

PB1 NO direct to L1 and thru PB2 NC to horn
PB2 NO direct to L2 and thru PB3 NC to horm
PB3 NO direct to L3 and thru PB1 NC to horn.

There is a problem with this if more than one button is pushed but the original question didnt mention more than one button being pushed.

Said it was a trick.

picture of what Ron said

quick and dirty picture of Ron's solution.


BTW, crossing wires are not connected, I left out a couple of "jumpers"

Re: picture of what Ron said

Ken Moore said:

quick and dirty picture of Ron's solution.

Click to expand...

Here's another of Ron's solution...
It looks like it will allow 2 lights on per PB.

deleted

that aint right...but thanks. I didnt explain correctly as usual.

I have it hand drawn but by the time I get it online someone will provide the answer...actually there is more than one answer.

rsdoran said:

that aint right...but thanks.

Click to expand...

Try explaining again...

Here's another. It depends on BREAK BEFORE MAKE pushbuttons and only 1 pressed at a time

      PB1

------] [-----+---------------------  Horn ---------------------

              |

      PB2     | 

------] [-----+

              |

      PB3     |     PB1           PB2           PB3

------] [-----+-----]\[-----+-----]\[-----+-----]\[-----+-------

              |             |             |             |

              |     LT1     |     LT2     |     LY3     |

              +-----( )-----+-----( )-----+-----( )-----+

this is very similar to the proficiency exercise i give to newly-hired maintenance techs. i give them a momentary pushbutton, with both n.o. and n.c. contacts, a "cube-type" octal base timing relay, a pilot light, and an alarm buzzer.
the test consists of wirng the components so that 1.the light stays on all the time, 2.the buzzer comes on when the timer "times out", 3.the buzzer can be cancelled and the timer reset by pushing and releasing the pushbutton. then, 4.the timing cycle starts all over again.
when they are done, (or before they start, if they want), they are required to make a drawing of their project, freehand, with pin numbers, wire numbers, etc. with the idea that anyone could pick up that drawing and duplicate their circuit.
no time limit, (within reason). some guys, and gals can do it in about an hour, some took as long as 3 hours, but, as long as it worked and the drawing was accurate, the amount of time taken didn't matter.
btw, this was all 120 vac and i provide a short power cord with plug on one end so they can "smoke-test" their apparatus when they're done, (with the rest of us watching the power-up from the peanut gallery).

grouch

You got it!

bernie_carlton said:

Here's another. It depends on BREAK BEFORE MAKE pushbuttons and only 1 pressed at a time

Click to expand...

I like your solution (but don't like your avatar).It is exactly what I've done. Is it your's, or someone else's solution?
I don't think any other idea shall work from above.
Thanks to all of you.

My own solution. I have my method - when trying a set of assumptions doesn't work (contacts in series with thing controlled) back up and try other assumptions. In other words its the "When your head hurts from repeated running into a brick wall, step back and look for a door" method.