Hello all, I'm new to this site so I hope I posted into the correct forum.

I've been trying to locate a sample design that would allow me the following function: Push a button and immediately send an "on" pulse...if I continue to hold down the button for another full second, start sending pulses at about 2/3 times per second until I release the button.

This kind of functionality is common on appliances, such as holding the Up/Down Channel buttons on a TV remote, or to quickly set a digital clock.

I get the feeling the ubiquitous 555 would be used in this scenario, but I've just too many gaps in my knowledge. Thank you!

 

More than one 555 (also known as a 556). Let the pushbutton send the first pulse (capacitively coupled) while starting "Timer one", a 555 configured as a one-shot. When timer 1 clocks out in one second, it allows a second 555 to start oscillating at 2/3 Hz.

Meanwhile, the button did an enable function, so when the button is released, everything stops.

That's a block diagram. The schematic comes next.

 

http://www.schematicsforfree.com/archive/file/Digital/Keyboards/Automatic%20Keyboard%20Repeat.pdf

Ken