since the original post asked for a positive pulse, solutions with capacitors will need to be flipped.:

 

since the original post asked for a positive pulse, solutions with capacitors will need to be flipped.:

TS never actually said positive pulse, however read post #11.

 

that is not how i read the first post but #11 does make more sense.

 

circuit in post 6 lacks connection dots making it hard to follow. and if it is what i think it is, it would not produce a single short pulse but a continuous signal while the button is held down. during that time, relay would oscillate and possible stretch the output a little.

 

i think it was meant to be something like this (for a positive pulse):

 

The first relay circuit posted would satisfy the requirements. If an isolated contact were needed the circuit provided that as well. If the whole thing had to be mains powered it would need a couple more parts, but still provide that short term isolated contact closure.

 

circuit in post 6 lacks connection dots making it hard to follow.

Yeah, sorry about that. I tend to forget them. I usually put arches across connections that are not connections.

 

Yeah, sorry about that. I tend to forget them. I usually put arches across connections that are not connections.

Those "arches" indicating no connection have a real benefit that even on the third or fourth copy they are still visible as crossings without connections.

 

Those "arches" indicating no connection have a real benefit that even on the third or fourth copy they are still visible as crossings without connections.

That's for sure. Some have complained that the arches are old school, archaic and out of date. I've liked them for years. Not having to draw in dots at all the intersecting connections while not specifying a connection every time a line crosses another.

Y'know what! I'm going to start using them again. Don't care what anyone says.

 

I don't like schematics without junction dots (or junction squares).
If you don't use connection dots, then a connection "junction" is open to interpretation (or misinterpretation).
Eliminate the guesswork by always using dots to indicate a connection junction.

 

Eliminate the guesswork by always using dots to indicate a connection junction.

True enough.

 

By the time a drawing has been photo-copied 3 times every junction has a dot. And it only takes one or two FAX transmissions to make every cross look like a connection. And a newcomer into the business might assume that every cross is a connection.
What is funny is that I never called them "ARCHES. In my mind they were "hop-overs". Even more of a functional description, but perhaps a bit odd.

 

The vast majority of drawings now are produced electronically, and can easily be transmitted, copied and stored this way.
Now commonly computer file transfer, VERY little FAX over now !
My FAX M/C went by the wayside many moons ago.

 

By the time a drawing has been photo-copied 3 times every junction has a dot.

That was done a couple generations ago.
Who now photo-copies drawings?

 

Neither a photocopy nor a landline fax can transfer any malware, and that is a valid reason to use them.

 

Neither a photocopy nor a landline fax can transfer any malware, and that is a valid reason to use them.

Generally those I deal with don't have one anymore either!