alternate channel switch

[netmgr]

I need a circuit that will direct a switch signal, say a + pulse via channel 1 first, and then when that pulse
has ceased will then wait for the next pulse and then send it via chanel 2, then repeat the process back to
channel 1

very similar to a latching flip flop but without the latching and 2 alternating output lines

all I can come up with is a flip flop which latches, I want the output to represent the state of the input
but on alternating output lines

that make sense!!??

any help would be fantastic as im getting nowhere!

 

[bychon]

The way I see it, you are trying to do it with too few parts. Picture a flip/flop that responds to the leading edge of the incoming pulse and enables a pass through device, like an analog switch or an op-amp with an enable pin. The next pulse will flip the flopper and it will enable the other pass device. My point is, one part is a decision maker and the other part is pass devices. On the other hand, some really smart person will probably be able to come up with a circuit that does this in one flip/flop. Until that person arrives, the simple way works. More parts, less brilliant deduction.

 

[netmgr]

the issue i see here though is that the second pulse will get through to the first device again before the flip flop
has had chance to switch to the second circuit, albeit a very short period of time

i really want a non latching circuit that alternates between 2 different output chanels for the duration of the
input

or perhaps im misunderstanding your idea?

 

[bychon]

You seem to be focusing on the idea that the flip/flop must be ready and waiting for the second pulse to arrive so that nothing of the second pulse gets to the first pass device. And, did you want toe flip/flop to be ready and waiting for the first pulse to arrive so none of it gets to the second pass device? Up till now, we were talking in abstract terms.

When you get down to the nitty-gritty, you have to provide things like, what size pulse? What impedance is the source? How fast is the rising edge? How long is the pulse? What is the load? Do you really need the flip/flop to be preset for each pulse, no matter which one arrives first or next?

 

[netmgr]

okay dokey, you are quite correct in your last reply in that ready and waiting...

Essentially i want a button, SPST, Push to make switch, 1st time i press it, the signal (+ or - no issue with either 12v or less) goes to the first device, a relay probably and holds that relay closed for the duration of the button press. The second press of the switch does exactly the same but to the second device, also probably a relay and at no point should that second press go to the first device and visa versa.
Then it should reset and start again, waiting for 1st press

Thanks so far for your assistance.

 

[bychon]

For a minute there I was thinking about megahertz signals that must be stopped without a billionth of a second error or the heart machine will stop and the patient will die. This is more like ringing the bell on a tricycle.

For Mouser part number 769-TS2-L2-12V
using 1n4001 diodes
This dual latching relay will set when you release the button and reset the next time you release the button. The dual latching relay will power a single pole, double throw relay which supplies the loads which are labeled, "RL".

 

[netmgr]

Looking good, but I cant find that part number on Mouser

 

[bychon]

sorry. Misprint. 769-TXS2-L2-12V

 

[netmgr]

Looking at this idea, it seems that this relay essentially has 2 coils, each one resetting the other?
does that mean that in either state its always using power by activating a coil?

the time between pressing of buttons on my design can be days and so having a coil activated all that time
would be quite a drain.

If thats the case I think I may just go with a pic of some sort, I just assumed that there would be a simple IC
that would do this, avoiding relays.

can a 4017 be setup to activate an output in succession for the duration of the input press or can it simply only
activate each output in turn?

 

[bychon]

The way I drew that, the first relay will stay on if it is in "second pulse waiting" mode. The dual coil flippenfloppen activates for less than a second at each button release. I did that because the dual coil thingy has only 1 amp of contact quality and you never said anything about idle current. You can re-arrange things so the dual coil relay carries the primary current to the RL things (whatever you're using there) because it has 2 (two) sets of SPDT contacts, and it won't use any idle current at all. Too cool, huh? Just forget the first relay and use the extra contacts inside the dual coil relay.**broken link removed**

On the other hand, there is nothing like the satisfaction of using a microcomputer to ring the bell on a tricycle.**broken link removed**

On the third hand, if you can program a microprocessor to do this, why do you need me to tell you to just use the extra contacts in the dual coil relay?**broken link removed**