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100V common mode diff front end amp?

Well if you clocked a flipflop inside the signal path? But it wouldn't be strict Manchester-like until you forced AC into the data stream to make the average zero requirement.

I didn't so that, and decoding Manchester has always remained a mystery to me, used a black box that does it ;) Which of course makes me wonder if you forced Manchester in the feedback path, would the analog data force correct digital sort of directly, automagically?

I'd like a decent current probe, Tek want anything north of $900 for one, so I made one from something I read on the 'net, it let me see a waveform, but of course no calibration. Some help, at the time I was investigating the nasty switching MOSFET drain to gate current injection, before I knew it was normal behaviour.

Grant.

Reply to
Grant
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Thank you. Hmm, INA333 4000 hours operation from LI coin cell! Better than +/-15V

Grant.

Reply to
Grant

You have a block diagram for recovery? I never got my head around the clock extraction, how it worked.

And, you have to take care about the data edge setup time (right term? make sure you don't glitch output, latching moving input data) on the encoder?

Grant.

Reply to
Grant

Yes, I looked at datasheet yesterday, wont happen in my world. They did quote that 30V limit for ground leads, but they do that now for handheld multimeter leads I bought recently. Maybe some country has a silly law?

Grant.

Reply to
Grant

The Manchester encoded signal has a transition in the middle of the cycle (falling edge of the clock). If that transition is positive, it's a '0', if negative, it's a '1'. The corollary to this is that if there is a transition at the beginning of the "cell", D(n) = D(n-1). A phase lock loop can pretty easily find the clock.

Reply to
krw

Here it is in words:

Run the input stream into an XOR+RC edge glitcher. Use that to fire a non-retriggerable one-shot set to 0.75 of the bit period. That one-shot will wind up firing at the middle of every bit cell, where there's always a transition, and ignoring the other transitions. So the one-shot output becomes the recovered data clock.

Now use the one-shot output and a D-flop to recover the data.

I could draw it if it's not clear.

I invented this when I was just a kid! We did a lot of supervisory control systems using Manchester data over FSK modems, all TTL.

John

Reply to
John Larkin

Off the top of my head... clock CVSD data into 2-bit shift-register, X-OR the 2 bits to get the output.

Without spending any time to check it out, I believe that decoding it was essentially the same routine. ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

      Remember: Once you go over the hill, you pick up speed
Reply to
Jim Thompson

just

:)

=20

=20

It seems like we have a global population explosion of silly laws recently. Decent people have let down their guard, or maybe it was battered down by insane courts.

Reply to
josephkk

Good bumper sticker:

QUESTION AUTHORITY

Better bumper sticker:

IGNORE AUTHORITY

John

Reply to
John Larkin

I'd like to add to the first one

WAIT FOR THE ANSWER AND THINK ABOUT IT.

Mindless rebellion is, well, mindless.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) net
http://electrooptical.net
Reply to
Phil Hobbs

When our oldest son was in about 3rd grade, his teacher called. She was quite upset. She had confronted Aaron, "You should learn to respect authority". Aaron replied, "My parents taught me to question authority". ;-) ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |

      Remember: Once you go over the hill, you pick up speed
Reply to
Jim Thompson

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