Simple pulse generator circuit

So they couldn't afford Howard Johnson or Martin Graham, who don't know much about high-speed electronic design either, but at least know enough about training to write a - crummy - book.

It looks as if the nuclear holocaust is still some way off.

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To what end? Would you admire the result, even if it were breathtakingly perfect?

I prefer to waste my time amusing myself - it's playing to a more critical audience.

In any event I'm off to Australia in a fortnight, and my wife wants me to focus on getting packed up and organised.

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What end? To design some real electronics.

I think your wife has chores scheduled for you anyhow.

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I've done that, and wouldn't mind doing it again.

Meanwhile iCod hasn't actually told us enough about what he's doing and what he wants his circuit to do to let us to design anything that might qualify as "real" electronics.

At the moment you've got the hots for the 74123 when it's only worth using instead of the 74121 when you need the re-trigger function, which doesn't seem to be necessary in the application. We are a very long way from "real" electronics.

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I'm sure yours could find something more useful for you to do too.

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don't see where it lends itself to easy adjustability from a front panel mounted pot- or the equivalent located at some distance from the high speed components.

ramp driving a high speed comparator, the other input of which is driven by a variable voltage threshold? The OP only wants a 25:1 pulse width adjustment so that's no big deal.

don't see where it lends itself to easy adjustability from a front panel mounted pot- or the equivalent located at some distance from the high speed components.

driving a high speed comparator, the other input of which is driven by a variable voltage threshold? The OP only wants a 25:1 pulse width adjustment so that's no big deal.

No. But thanks for trying.

?-)

where it lends itself to easy adjustability from a front panel mounted pot- or the equivalent located at some distance from the high speed components.

a high speed comparator, the other input of which is driven by a variable voltage threshold? The OP only wants a 25:1 pulse width adjustment so that's no big deal.

This has 60 ps edges and makes a nice 100 ps FWHM pulse, 100x less than your "difficult" 10 ns. It uses a linear ramp and two comparators, to program both delay and width. It's made from Digikey-level discrete parts. It wasn't terribly difficult, and worked first time. The biggest chore was e/m simulation of the geometry of the PCB and the edge-launch SMA connectors.

There just aren't many ways to make a programmable pulse in the hundred-picosecond range, for less than the price of a Porsche.

Schematic of what? I forget.

Schematics of the above J240 ?:-) ...Jim Thompson

Sorry, not that one.

But I posted the wrong link. I meant this one:

I have the darndest time remembering my own model numbers. Too many of the danged things.

It wrapped correctly for me.

Ed