Decode voltage polarity to differential logic signals

Status
Not open for further replies.

Thread Starter

DonEM

Joined May 29, 2021
6
Thanks for some design ideas to prime my head on this. I've forgotten everything I learned years ago.

No archive search satisfaction. Help an old rescue dog...

The hobby-design problem:

In general, the design needs to flip or flop a differential output pair when the current goes one direction or the other.

When perfected, the direction-detector output will drive a half-bridge that creates current directionally through a shunt.

The application is as half-bridged-shunts with current-direction-sense that triggers along the sequence in a daisy-chain of reversing shunted-conductors. That's later.

If the power sourcing current shares a neutral/ground with the logic power supply, what kinds of minimal ways could a flip-flop toggle when shunt-current reverses? General terms are great. I'll draw it out to understand it better if my head holds together.

The direction-detection output needs to toggle on negative and/or positive voltage drops across the shunt.

I assume a Zener diode(s) could be chosen in a windowing-comparator with an op-amp, but something simple with a 'negative part count' would be right down my alley (old hacker tricks are cool, and air-wire circuit-sculpture is likely for starts). The vague design in my head stops about here.

The social interaction is a positive on hopes of ramping the learning curve with gecko feet (sticking to it). Thanks for helping Grandpa!
 

Thread Starter

DonEM

Joined May 29, 2021
6
Please do so. Your description is not exactly clear but a picture will help us work out what you need.
Hi DC,

But it is not so easy to draw what I don't understand to draw, therefore a discussion. I'm asking for pointers for where to start my own drawings. Sorry I was vague.

I'm after starting-ideas.

Working grammatically toward a circuit realization, the problem is simple:

If voltage drop on the current-shunt is positive, then toggle differential logic outputs to 1 and 0.
If voltage drop on the current-shunt is negative, then toggle differential logic outputs to 0 and 1.

The question is revised: What simple analog circuit technique/trick/scheme will provide toggling the outputs of a flip-flop when the shunt voltage swings above or below a positive and negative threshold window?

I know I'll need to rectify the shunt voltage back to positive-logic levels when the shunt voltage drop is negative, below the logic ground.

I assume two Zener diodes could clamp the +/- voltage swings across the shunt.

So, Zener current could activate the input A of the flip-flop (falling-edge triggered).

But input B of the flip-flop needs the Zener current from a negative shunt voltage drop to be translated to positive voltages (up to logic levels).

I would love to be able to invert the negative shunt voltage without a transistor.

Does anyone know of another approach that will work better?

Hey! What if my flip-flop were discreet transistors?

Could a discreet-flip-flop be built to operate with positive/negative input voltages directly? A flip-flop riding the fence (biased for zero-reference to be the center of the +/- voltage swing?) perhaps.

Thoughts, anyone?


Over,
DonEM
 

Yaakov

Joined Jan 27, 2019
3,152
This appears to be a proposed solution to a problem, not the problem itself. Could you describe the problem this is the solution for to give some context? It would help a lot. It doesn't seem to be a very difficult thing, but we are working half-blind.
 

Alec_t

Joined Sep 17, 2013
12,064
Is the current shunt grounded at one end or floating?
What is driving the current through the shunt?
How much current?
What supply voltage?
 

Thread Starter

DonEM

Joined May 29, 2021
6
This appears to be a proposed solution to a problem, not the problem itself. Could you describe the problem this is the solution for to give some context? It would help a lot. It doesn't seem to be a very difficult thing, but we are working half-blind.
Well, please see the first post for a use-case scenario.

Really? The proposed solution I assume you mean the customized flip-flop.

I'm confused. The idea is for discussion as a solution to the problem described just above in the same message.

Bear with me folks. It seems I'm responding to curious questions about the whole project, which is later, sorry. See the first post for the use-case, which is later.

This project is about a computer-science analysis in the time domain based on 4-bit time-stamps of cycle-times a running ring-amplifier.

The completed project will be akin to fully digital version of a spectrum analyzer --but different, as it will analyze timing-variations in RF oscillator cycles with various channels of analysis over a sense of history. The digital version when fully realized will serve as a controller for isolating time-domain anomalies under study. The device is experimental made to serve my needs. This project is science, not electronics, but electronics is used to set current patterns in copper elements. The time-domain analysis will mature with revisioning into an FPGA solution feeding visual displays of category patterns in the edge-jitter of a ring amplifier tuned to anomalies in the magnetic near field of the device. Call it a tricorder.

Meanwhile, back at the ranch...

The original grammatical problem of the focus is clear. Differently stated: Share thoughts on how to level shift a plus/minus potential to differential logic inputs.

If that is not clear, I need to help you, not vice versa.

If you can help and want to only help with the full picture of the project available, then contact me off-list... because I am not an electronics tech but an old man on a mission. This mission has lots of room for collaboration.

I am tickled and smile at the questions.

Let's return to the problem domain.

Thank you!
 

Yaakov

Joined Jan 27, 2019
3,152
Well, please see the first post for a use-case scenario.

Really? The proposed solution I assume you mean the customized flip-flop.

I'm confused. The idea is for discussion as a solution to the problem described just above in the same message.

Bear with me folks. It seems I'm responding to curious questions about the whole project, which is later, sorry. See the first post for the use-case, which is later.

This project is about a computer-science analysis in the time domain based on 4-bit time-stamps of cycle-times a running ring-amplifier.

The completed project will be akin to fully digital version of a spectrum analyzer --but different, as it will analyze timing-variations in RF oscillator cycles with various channels of analysis over a sense of history. The digital version when fully realized will serve as a controller for isolating time-domain anomalies under study. The device is experimental made to serve my needs. This project is science, not electronics, but electronics is used to set current patterns in copper elements. The time-domain analysis will mature with revisioning into an FPGA solution feeding visual displays of category patterns in the edge-jitter of a ring amplifier tuned to anomalies in the magnetic near field of the device. Call it a tricorder.

Meanwhile, back at the ranch...

The original grammatical problem of the focus is clear. Differently stated: Share thoughts on how to level shift a plus/minus potential to differential logic inputs.

If that is not clear, I need to help you, not vice versa.

If you can help and want to only help with the full picture of the project available, then contact me off-list... because I am not an electronics tech but an old man on a mission. This mission has lots of room for collaboration.

I am tickled and smile at the questions.

Let's return to the problem domain.

Thank you!
Sorry for trying to help, I won't make that mistake twice.
 

Thread Starter

DonEM

Joined May 29, 2021
6
This thread shocks me!

This thread has served to show me that the people that respond first are 1) People that haven't read the whole message, and 2) People that provide critique that exposes that they want to be negative before they understand my question. 3) That the responders are hung up on 'show me' level of comprehension, and do not have the background to understand 'level shifting' to logic levels from a positive and negative voltage drop over a current shunt.

As a day-one newbie I have clicked the ignore button on two old members here.

And ... doh ... you my wonderful person are a young pup if you yet don't really get the point of the inanity of this thread.

Is there anyone here that will try to return to the original spirit of a question of level shifting? We all know I should abandon this thread, but damn it, it really is wrong... so my indignation is online now.

I'm looking for tricks and tips form the old dogs, not noise form the young pups. I eat puppies.

Please show me this place isn't systemic with what the beginning of this thread suffered.

Now, back to an electronic design problem of an old man that took electrical engineering in 1973.


Level shifting is the grammatical talking point <-- Renew my neurons please.

An AC signal on a shunt needs to have level shifting where positive and negative are decoded to 1-0, or 0-1 on differential outputs.

And I'm your friend for pity sakes!
 

DickCappels

Joined Aug 21, 2008
7,424
@Alec_t I think he is doing the best he can at the moment.

You use the word "toggle" could you as well use the term "change state". From what I read no flip-flop is needed, just a voltage comparator could do this, at least as far as my understanding goes.
1622377192742.png
 

andrewmm

Joined Feb 25, 2011
1,464
Thanks for some design ideas to prime my head on this. I've forgotten everything I learned years ago.

No archive search satisfaction. Help an old rescue dog...

The hobby-design problem:

In general, the design needs to flip or flop a differential output pair when the current goes one direction or the other.

When perfected, the direction-detector output will drive a half-bridge that creates current directionally through a shunt.

The application is as half-bridged-shunts with current-direction-sense that triggers along the sequence in a daisy-chain of reversing shunted-conductors. That's later.

If the power sourcing current shares a neutral/ground with the logic power supply, what kinds of minimal ways could a flip-flop toggle when shunt-current reverses? General terms are great. I'll draw it out to understand it better if my head holds together.

The direction-detection output needs to toggle on negative and/or positive voltage drops across the shunt.

I assume a Zener diode(s) could be chosen in a windowing-comparator with an op-amp, but something simple with a 'negative part count' would be right down my alley (old hacker tricks are cool, and air-wire circuit-sculpture is likely for starts). The vague design in my head stops about here.

The social interaction is a positive on hopes of ramping the learning curve with gecko feet (sticking to it). Thanks for helping Grandpa!

" The application is as half-bridged-shunts with current-direction-sense that triggers along the sequence in a daisy-chain of reversing shunted-conductors. "

may be you could draw that out for us please
 

Thread Starter

DonEM

Joined May 29, 2021
6
Hi Dick,

No, I mean toggle. A flip-flop is bistable and is used in the mystery circuit revealed in block-text below.

The flip-flop is an element of the design that is toggled by the desired signal shift and decoding needed as a two-state memory element.

Here is the title of the thread: "Decode voltage polarity to differential logic signals"



Here is the design-blocks of the system that will host a polarity-decoder...

Positive rail |
| half-bridge --- [conductor under study] --- *sense-point*[shunt resistor][neutral rail]
Negative rail |

The half-bridge will switch either the positive or negative power supply rails through the study-conductor and to the neutral rail through the shunt-resistor.

The polarity appears on a current shunt proportional to the current.

That shunt polarity needs to decode to two signals, by routing the signal to differential signals.

A latched-polarity-detector circuit connects to the *sense-point* to 'decode the direction of the current' to differential outputs.

The following block-text depicts the polarity-detector design-blocks...

*sense-point*
|
|
****************************** ******************************
* * -- logic-output A -- * * -- latched-output A
* Unknown design pattern * * Flip-flop *
* * -- logic-output B -- * (latches output pattern) * -- latched-output B
****************************** ******************************

Output B is always opposite A, as a differential pair, by the nature of a flip-flop (see google).

---
Circuit Operation of the switched-conductor w/latched-polarity-detector (differential) outputs:
* A half-bridge will flow current to a neutral buss through a shunt.
* A circuit in the *unknown design block* will toggle differential logic-outputs to reflect the direction current is traveling through the shunt.
* A latching flip-flop will provide latched-outputs <-- which are only used to to drive the half-bridge differential inputs of yet another switched-conductor-unit.
---

To the mildly curious:

The application intended for a half-bridge-switched-conductor (HBSC) (w/directionality sense) is to connect the half-bridge differential inputs to the outputs of another HBSC unit, and connect multiple units in a chain, inputs to outputs.

A source-signal at one end of the HBSC chain will reach the other end after a total of the semiconductor component propagation time, and the inductive lag-time of the conductor element.

The characteristic inductance of the HBSC conducting element is studied at radio frequency by using fast transistor components at radio frequencies (GaN half-bridge dev. boards for prototype at six-quantity HBSC per rotary system assembled.)

Radio frequencies are produced by a short chain of odd-numbered HBSC units connected in a ring.

The ring oscillation includes the inductive conductor elements physically arranged in antenna-fashion (toroidal). A time-domain study of timing anomalies of a magnetic vortex, proper, are so established (using co-occurrent categorization of a sensor matrix of everything sensorizable of the normal and anomalous behavior. Not much different than a screen-saver that moves to the spectral dynamics of music... but at RF and about the magnetic topology, like the Van Allen belts are akin to Earth magnetism, but structured. This project looks for patterns in magnetic stabilities in a log of time-stamps (4-bit) captured live, processed near-live for visual acuity involvment in the hunt for anomaly at the magic frequencies of rogue science by others. I'm just the book binder, to self-promote Faraday's humility. These unrecognized scientists (in mainstream curricula) sure seem to be on to something from the viewpoint of my amateur passion.


DonEM
@Alec_t I think he is doing the best he can at the moment.

You use the word "toggle" could you as well use the term "change state". From what I read no flip-flop is needed, just a voltage comparator could do this, at least as far as my understanding goes.
View attachment 240001
Hey, thanks for the intervention, Dick!

It's useless to try to paint pictures with words, and I've been guilty of less than patient with the rabble.

Now... practicality. I will maybe get back to you guys if my original feelings of sharing anything I know as a bad taste now returns to some hope of being engaged intellectually without the animalisms engendered in common forum speak where people with somevariable
.
 

Ian0

Joined Aug 7, 2020
2,189
Sounds like the sort of project that could wipe out radio communications over a large area, especially as all these high-current "elements" are arranged in an "antenna-like fashion"
 
Status
Not open for further replies.
Top