@KMoffett;
Just wondering, which one is the reference node, + node and the - node...thanks

To go with beenthere's post, this is a UJT based ECG rate/amplitude calibrator that I designed as a student for a Biomedical Electronics class back in the 70's.

I have another one that a friend made with 555s that replicated actual 12-lead waveforms. I'll have to dig that out.

Seems like that a microcontroller with a look-up table and a filtered PWM output would be the way to go now.

Ken

 

Welcome to the forums.

Your post hijacked an old thread - http://forum.allaboutcircuits.com/showthread.php?t=44366&page=3

We'll let you have your own to get that question dealt with.

 

As I recall...J3 was common, J2 was a +1mV pulse and J1 was a +1V pulse.

Ken