Hi. All, i have a question and hope this on a right section and please let me know if i am wrong.
I have make relay switching circuit.But the problem is i have only one command pulse to make a change.
So i have conclude that i need a circuit if i give a 2 pulse in specified time it switch the relay on and if only 1 pulse after that specified time it will turn of the circuit.
Any idea how to make this circuit ?
I think it related with flip flop kind circuit but I still can't get any solution right know.
Thank you for any response and i am sorry for bad english.
Regards.
Would it be acceptable for one pulse to turn it on and then another pulse will turn it off (alternate action)? That's much easier than trying to differentiate between one pulse and two pulses.
Would it be acceptable for one pulse to turn it on and then another pulse will turn it off (alternate action)? That's much easier than trying to differentiate between one pulse and two pulses.
That was my first solution after I discovered that if only one pulse to on or off the switch it depend on when it start... So we need to know what the initial pulse mean... on or off.
With differentiating 2 pulse, it doesn't matter to start in any condition.
So far I've get the idea and will post it soon.
Here is the idea, it wait until 2 pin A and B get a high logic each pin delay depend the cap discharge time, so the OFF pin is active.
But the problem is when each A or B is active the other is low so it will make cap discharge too.
the block after the cap is voltage comparator to make a high logic on specified volt to pass to logic gate.
any idea or simpler solution will be appreciated... **broken link removed**
I've try that diagram on bread board with LM311 and 74LS00 (manualy do toggle flip flop) and make no luck, the high logic doesn't hold like a want. And the cap was discharge quick. I am sorry for bad picture above, I am using Linux and still couldn't find a schematic drawer software.
Any solution or response will be really appreciated.
Here's a circuit that does what you want. It uses a dual FF, an inverter, and a 555 one-shot.
The one-shot period determines how long it looks for the two pulses (the values shown give a little over one second).
With a double-throw switch you don't have to worry about switch bounce. The switch is wired such that pushing the switch causes the trigger to go from Vcc to ground. Two pulses gives a high at the Output, and one pulse gives a low.
If you want the output to be in a particular state when circuit power is applied, you can apply a momentary reset pulse to SD2 or CD2 from Vcc using an RC circuit.
It's not shown on the schematic to avoid clutter, but all unused inputs should be grounded.
Thank you crutschow for help... Light my day.
One more question for input signal, how to make circuit to give two pulse where on and one pulse when off generated from double-throw switch OR ordinary on off switch ?
Thank you very much...