voltage pulse sensor

Errr..... Say you bought a *meter* that could detect pulses like that, and say it gave readings of pulse width and amplitude. Then what? The meter would be useless for doing something else, specifically flashing an LED. You do not want or need a meter. Some simple logic and timers will do the job. The input pulse could drive a comparitor (or two) to determine amplitude (or amplitude range); the output feeds a one-shot and logic to determine pulse width, and the output then drives an LED flasher (a timer and driver).

The operative term for what you need is a Pulse Stretcher. Take a look at the datasheet for the LM555 timer.

The LM555 will do what you want in monostable mode. The datasheet describes the circuit and equations to design it.

If you don't feel that you can handle the details of designing the circuit, you might download freebie designer software at

and let your computer do the work for you. For the output pulse width, you would probably have to use something in the neighborhood of 250 ms in order to make the flash of the LED visible. Amplitude is a minor problem here, since your pulse is too low to trigger the 555 timer. A simple opamp or comparator circuit will do the job nicely. If you try this approach, first select the 555 Monostable button, then select either the Positive Edge Triggered Monostable or the Negative Edge Triggered Monostable, depending on the polarity of the pulse coming from the opamp/comparator.

If you're only driving a single LED, the 555 output can drive it directly. Be sure to put a limiting resistor in series with the LED.

--
Dave M
MasonDG44 at comcast dot net  (Just subsitute the appropriate characters in 
the address)

Never take a laxative and a sleeping pill at the same time!!

Have you tried looking for a Logic Probe?

Good luck.

John