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Use 5sec pulse to generate only .5sec pulse ? Answered

Hi, i use an internal relay of a phone system to open a garage door and the time of that pulse is 5sec and is the minimal time, but i need make a .5sec pulse to close, how can i use the 5sec pulse to generate another .5sec for close the door or just a momentary pulse ?

Thanx !




7 years ago

So regrettably the 3 IC circuit diagram that responds to calls by providing a 5sec pulse followed at the same terminal a o.5sec pulse in response to the next call Was too complex  :-Þ.   A


Thank you very much and ill try this from you, actually i install today the little box on the motor and it works perfect.

Thank you again

Tanks for the response :-) to a grumpy old fart.
If you have something Working don't fool with other stuff...
And give whoever put you on the track or yourself ( Best Answer )

I like your solution better.


Thank you very much to all, i found the solution very simple and i want to share

1 relay
1 cap 470uf
1 diode
1 resistor 560ohm

so, this circuit let me to have a pulse of any time IN but in OUT always i have .3sec obviously depends of the values of cap and resistor.



Monostable multivibrator?

the only problem is that i need a short pulse start to have a .5sec in the end, but i dont have a short pulse, with 5sec the end dont release the .5sec,

Correct me if i wrong

Thank You !

you are wrong :)

You can set it up as a 'one shot' monostable - regardless of the input, the output won't go high again until the input goes low, allows the circuit to reset, and then goes high again.

You are right, but i cant makes to work...do you have the schematic ? somthing i do it wrong..

thank you !


7 years ago

So here is a Two-Timer schematic.
I hope this one is easier to see...
How it works is, After pressing Close;
  • The next call causes JK U3  Q to go low triggering Timer U1 to output a 5 sec pulse OR-d by U4 and presented on pin 10 U4C..
  • The next call causes not_Q of U3 to go low triggering Timer U2 to output a o.5 sec pulse OR-d by U4 and presented on pin 10 U4C..
  • Repeat  as needed
A micro is still desirable at handling the special special cases that are gonna come up :-)


How exactly does this system work (with pulses)?
You've not even said what sort of pulses are involved here...


the motor of the door garage works this way,,,to open can be a pulse of 5 sec and works fine,,but to close that 5 sec pulse the motor close-open-close-open all the time and finally stay open, so i need to make only a momentary pulse to close and that momentary pulse works to open too..at last i need only a momentary pulse to open and to close, but the phone system have 5sec pulse.

so i need to use the 5sec pulse to activate a circuit to make maybe 5v output momentary for activate another relay to close...

but i lost in the circuit part.....i think the monostable 555 can be the solution,,or maybe another circuit that no matter what pulse time use at start at the end i need just .5sec

Thank you very much

Is this hard-wired or infrared, radio etc? - I don't understand which bit of phone system is used very well.
0.5 seconds could be done with a momentary-switch and a finger.


The momentary switch is make with the phone system from any phone of the house (552extension) but is not momentary is 5sec on,,,, i want to convert to .5sec time switch.

i looking for something like this, the phone system is the "relay1"

Relay1 5sec in -->Circuit-->Relay2 .5sec out

BUT i need a circuit that no matter the time switch IN is (Relay1), at the end only need .5v or 12v from the circuit to activate the relay2 for .5sec to close

Thats all

So you're dialling the phone to operate the door then, OK.
What you're asking sounds like "how do I make the phone ring differently?".
I'm a bit stuck, because I can't see the circuit diagrams and don't know how your phone system works...


you dont need know how the phone system works, that part is just a switch on for 5sec and then off (is a internal relay), i want to use that time to convert to an .5sec switch on and off, because the motor of the garage works with less that 1sec, just need to make another switch of .5sec connected to the motor of the garage,, thats all...

The motor have 2 screws if you connect a pair of cable and you put it together momentary the motor moves open, and if you doing again the motor close, but only to close if you put it that cable together for more that 1 sec the motor close-open-close-open cycle, thats why i need .5sec switch at the end.

Thanx !


7 years ago

Complicating, because it is past midnight here..
Complicating it into ( Not 2 ) three time periods.
  • (A)  A 5sec open pulse low-high-low  Triggered_by_User.
  • (B) An arbitrary 27sec entry / exit  pulse low-high-low.  Triggered_by_A
  • (C) A o.5sec close pulse low-high-low.  Triggered_by_B.
So, you start A (OPEN) which starts B (WAIT) which starts C (CLOSE)

Nite Nite from A

ill make the simulation, ill inform you anything

Thank you

I used a new calculator for the three RC timing values and recently found it sets
the values high, you may have to down size R and C values,sorry.

What software are you using to make the simulation ?

Crocodile Technoligy

Though it's much later here, it is just past midnight here right now...

Why three 555 stages (I know, you can't have enough 555s)?
The last (rightmost) stage should be enough for the OP.

Just to show of how one can link a triggered sequence of them.


Thanx, but i want to use one pulse to open and later use another pulse to close, not to be automatically
someone in the house type 552 in the phone and open the door and that person need to type 552 again to close, every type is a pulse of 5sec but i need .5sec

Best Regards !

+2 555 timer solution.