PI Circuit from Carl

[Russ]

Hi Folks,
I was just wondering if anyone else is working on the PI Circuit that Carl posted on the PI Forum. I have been building it in sections and testing it prior to putting it on a proper circuit board. So far I have the transmitter and timing sections working fairly well. I did redesign the power supply section so I could use parts I had on hand, but will probably go with the original design since it is smaller and probably more effecient. There was quite a bit of interest in the design shortly after it was posted but I haven't seen anyone comment on it recently. I still have to acquire a few components but should have the unit completed within a couple weeks, time permitting. I sure would be interested in comparing notes with anyone else who is building the unit.
Thanks

Russ_NY

[Carl]

Re: PI Circuit from Carl

Believe it or not, I'm actually working on it. The first PC board had a few glitches, and I decided to completely redesign the audio section. I'm now working on a new PC board. I hope to finish it up this week, and I will post new info on it.

- Carl

[Russ]

Re: PI Circuit thanks Carl

Hey Carl
Good to hear from you. I am having a great time working on this circuit. What had you intended as a transmit repetition frequency? Mine is currently set for 1 KHz, with a 100usec transmit pulse width. I have an initial sample pulse delay of 15usec, a 15 usec sample pulse and the second 15usec sample pulse occuring 100usec after the first, which I understand is fairly typical. I have some parts on order so that I can work on the remainder of the circuit. I look forward to seeing your revisions.
Thanks again for the response.

Russ_NY

[Carl]

Re: PI Circuit thanks Carl

Russ,

The whole concept of this PI design is "variable everything". It is intended to be an instructional platform for those who want to learn about basic PI detection.

Variables include frequency, pulse width, sample delay, sample width, optional differential secondary sample, secondary sample delay, inverting & non-inverting operation, auto- and non-auto-tracking, auto-track speed, vco and non-vco audio, sensitivity, threshold, and, of course, volume.

There are no intended settings for anything, but I will probably eventually nail down a lot of the parameters, and then redesign a simplified PCB. At that point, I will probably also switch to all surface mount devices.

- Carl