@ All,

Subject Ref.: Engineering Schematic Diagram

15-COIL LINEAR CHAIN WITH DUAL SSD SELECTORS
*Moving 8-Coil Window*

@ All,
 
Subject Ref.: UPDATED Engineering Schematic Diagram
CORRECTED Solid-State Version: 
No common Return Bus * Individual SR Returns *  Make-Before-Brake
15-COIL LINEAR CHAIN WITH DUAL SSD SELECTORS


I have posted a revised version of the schematic after identifying and correcting two critical issues in the original approach.

Key Corrections
1. No Common Return Bus

• The previous shared return path has been eliminated.
• Each return (SR8–SR15) is now individually switched.
• This prevents unintended current paths and cross-coupling between coils.

 
2. Make-Before-Break Switching

• Selector transitions now require overlap (turn ON next pair before turning OFF the previous pair).
• This avoids inductive kick, field collapse, and voltage spikes.

 
Architecture Overview

• 15-coil linear chain (Q1–Q15)
• Dual selector system:
  
  • Left side (SL0–SL7) connects to +V
  • Right side (SR8–SR15) connects to return (GND)
• Each selector implemented as a back-to-back MOSFET pair
• Active region is an 8-coil "sliding window" across the chain

Example:

• G3 = SL2 + SR10 → activates Q3–Q10

 
Important Notes

• Do NOT tie N0–N15 together (no shared return node)
• Use isolated/floating gate drivers for each selector
• FPGA/control logic must enforce only valid SL/SR pairings
• Current-controlled supply strongly recommended
• Include fault protection (overcurrent, thermal, driver fault, E-stop)

 
Valid Selector Pairs

• G1: SL0 + SR8 → Q1–Q8
• G2: SL1 + SR9 → Q2–Q9
• G3: SL2 + SR10 → Q3–Q10
• G4: SL3 + SR11 → Q4–Q11
• G5: SL4 + SR12 → Q5–Q12
• G6: SL5 + SR13 → Q6–Q13
• G7: SL6 + SR14 → Q7–Q14
• G8: SL7 + SR15 → Q8–Q15

 
This UPDATED version should now be electrically robust for Solid-State Switching 
without unintended current paths or switching transients.

Open to feedback, especially on gate drive strategies and protection schemes.

Regards, Alex

Hello dear friend Alex,

I was already writing a post to outline all my questions and doubts on your previous diagram...as I noticed there were confusing circuits like ALL the Ground Nodes shorting ALL Coils...

Now I see you have corrected this diagram, as now I fully understand it.

Do you want me to delete previous diagram on post?

Regards

Ufopolitics

Hello my friend Ufopolitics. 

No need to delete the previous schematic this actually part of the learning process and shows the evolution of the design.
You were absolutely right to question the common ground node issue. 

That was a key flaw, and your attention to it is exactly the kind of critical review that helps refine these systems.

The updated version corrects that by removing the shared return bus and enforcing individual SR paths, along with proper make-before-break switching.

I appreciate you taking the time to analyze it so closely and feedback like yours is what drives these improvements forward.

Please feel free to continue with your questions or observations, even on the earlier version. 

There is value in understanding why it did not work as much as why the new one does.

Kind regards, Alex

Hello dear friend,

So, I did a Diagram based on yours...to see if I understand the whole setup, now that you have corrected, please feel free to point out any errors I may have there:


Basically only main difference between mine and yours, is that I have identified each Selector as an enclosed normally open switch, to then connect other end to the coils terminals...is this a correct interpretation?

One part that I do not see any connections or points to be, are all the 15 Nodes on the below area...unless you have a specific job for these Node Terminals.

Regards 

Ufopolitics