On 22 Nov 2005 21:41:19 GMT, (Steven Swift) wrote:

Greetings.

A short while ago, I posted a request for links to simple triggered
sweeps for older recurrent timebase oscilloscopes. I spent a fair
amount of time looking in old magazines and circuit handbooks, but
didn't find what I thought I was looking for.

So I decided to cobble-up a homebrew of my own. This circuit probably
has been done before, but it met my criterion of being really simple.
I used already on-hand parts, so the design is far from optimum. It
works fine on an Eico 460 up to about 1MHz. No attempt was made to make
a calibrated sweep. You could use a 5v rail and an HC4538 to make a
nice high speed triggered sweep.

Have a look at:

http://novatech-instr.com/Fun/trig.pdf

Thank you to all of you who sent me emails and posted comments on these
boards.

Steve.
Seattle,WA.

Pretty good. Did a similar thing using 3 555s. One was used as a
threshold detector, one for the Onshot (with a FET constant current
source) and one for the retrigger holdoff oneshot. Worked to well
to beyond the 5mhz scope it was used with.

Allison