Finding the Right VCR/VDR or VCO to Make a Variable Length Pulse

[madmike159]

I need to make a pulse of varing length. Either I need a VCR/VDR to control the length of a momo stable pules, or a VCO to trigger a preset monostable at different times.

I have been trying to find some thing to do the job for me but havn't had any luck. The VCR2N/4N/7N made by Siliconix are no longer made, and I can't find any where that stock them or any thing similar.

Can anyone tell me where to get hold of something which will work?

 

[Averagesupernova]

Triangle wave fed into a comparator with an adjustable reference.

 

[berkeman]

or a 74HC4060 with Xtal and a little decode logic...

 

[madmike159]

Thanks for the help guys. I found a way to make a VCO from a 4046B.