Samsung motor

Hi Warren, all,
 

 Here is the start of my motor controller, making the PCB with Target 3001 (free version) and a GRBL CNC mill. Do the design in Target 3001 and it spits out the G code to run the CNC 2418 mill. The sense resistors will be on another board.
 

 https://www.youtube.com/watch?v=QiJPdxUojRo&feature=youtu.be https://www.youtube.com/watch?v=QiJPdxUojRo&feature=youtu.be

 

 How is your's coming along?
 

 Ron

Hi Ron,

I see no decoupling capacitors across the voltage supply terminals of the MOSFET drivers. This is asking for trouble. The current when charging the input capacitance of the rightmost MOSFET has to go from the voltage supply to terminal J1 and through the green path to reach the gate of T6 and return through the yellow path to J1 and back to the voltage supply. When discharging the gate of T6 the blue path through leg 4 of U3 and back to terminal J1 and the yellow path back to T6 is taken.

The big loops formed stores magnetic (inductive) energy that kicks back with voltage spikes when the current is rapid changed. Current can't be discontinuous in inductive circuits which makes them induce voltage to compensate. This may cause instability or even destruction of weak components. Consider it like instantly changing the rotational speed of a flywheel. It will break the axle or something else by the kickback. The yellow return path is shared with the wide ground path. This path may have voltage drops when switching big or fast current. The gate of T6 is in series with this path and directly sees any voltage induced along this path. The normal practice is dividing this track into two separate tracks. A wide one for power and a narrow one for control signals. The yellow path should follow the green path the short distance between T6 and go to a decoupling capacitor at leg 4 of U3. This decoupling capacitor is like a small local power supply or battery close to where the energy is needed. Read Ivor Catt about transmission line theory to know why. Catt had his troubles back in the 1950's when working with the very fast emitter coupled logic.
 Place decoupling capacitors as close as possible to the voltage supply terminals of the MOSFET drivers (leg 1 and 4). Decoupling capacitors may be needed across the positive and negative voltage supplies of the MOSFETs. I.e. across the drain of the top MOSFET to the source of the bottom MOSFET.
 Minimize the big loops formed. Don't share signal paths with power paths to avoid instability.
 Regards
Ole


 

---In [email protected], <iron1of1@...> wrote :

 Hi Warren, all,
 

 Here is the start of my motor controller, making the PCB with Target 3001 (free version) and a GRBL CNC mill. Do the design in Target 3001 and it spits out the G code to run the CNC 2418 mill. The sense resistors will be on another board.
 

 https://www.youtube.com/watch?v=QiJPdxUojRo&amp;feature=youtu.be https://www.youtube.com/watch?v=QiJPdxUojRo&amp;feature=youtu.be

 

 How is your's coming along?
 

 Ron

Thanks Ole for the critical analysis of my poorly laid out circuit! 

 There is a 10uF cap on pin 4 in Patrick's circuit that I left out, my bad.
 

 Being an Ivor Catt fan I hear what you are saying.
 

 Lots of room on the board to add these caps, will do.
 

 I was focused entirely on GRBL and my problems with getting the CNC to work that I ignored this detail. You can see when I am drilling the board is bouncing up and down... these were the issues I was focused on. This was only the second board that I had done with any degree of success.
 

 The message was, "see? if a dumb dumb like me can do CNC then you can too", that and a little poke at Warren who has been encouraging me to, "get on with it"
 

 Thanks again 
 

 Ron
 

 
 

---In [email protected], <onielsen@...> wrote :

 Hi Ron,

I see no decoupling capacitors across the voltage supply terminals of the MOSFET drivers. This is asking for trouble. The current when charging the input capacitance of the rightmost MOSFET has to go from the voltage supply to terminal J1 and through the green path to reach the gate of T6 and return through the yellow path to J1 and back to the voltage supply. When discharging the gate of T6 the blue path through leg 4 of U3 and back to terminal J1 and the yellow path back to T6 is taken.

The big loops formed stores magnetic (inductive) energy that kicks back with voltage spikes when the current is rapid changed. Current can't be discontinuous in inductive circuits which makes them induce voltage to compensate. This may cause instability or even destruction of weak components. Consider it like instantly changing the rotational speed of a flywheel. It will break the axle or something else by the kickback. The yellow return path is shared with the wide ground path. This path may have voltage drops when switching big or fast current. The gate of T6 is in series with this path and directly sees any voltage induced along this path. The normal practice is dividing this track into two separate tracks. A wide one for power and a narrow one for control signals. The yellow path should follow the green path the short distance between T6 and go to a decoupling capacitor at leg 4 of U3. This decoupling capacitor is like a small local power supply or battery close to where the energy is needed. Read Ivor Catt about transmission line theory to know why. Catt had his troubles back in the 1950's when working with the very fast emitter coupled logic.
 Place decoupling capacitors as close as possible to the voltage supply terminals of the MOSFET drivers (leg 1 and 4). Decoupling capacitors may be needed across the positive and negative voltage supplies of the MOSFETs. I.e. across the drain of the top MOSFET to the source of the bottom MOSFET.
 Minimize the big loops formed. Don't share signal paths with power paths to avoid instability.
 Regards
Ole

Ole, 

 How do you send a photo? I have never been able to do that in Yahoo.
 It always comes out with the small square and green slash... or blank like Norman's last post?
 

 Ron

Hi Ron,

Use formats that browsers can handle like jpg jpeg gif and png. Then I drag and drop the picture file into the message field of Yahoo when opened in a browser. It doesn't always work. It often works when also attacking the picture files besides dragging and dropping them. The part of the message after the picture sometimes is missing.

Regards
Ole
 

---In [email protected], <iron1of1@...> wrote :

 Ole, 

 How do you send a photo? I have never been able to do that in Yahoo.
 It always comes out with the small square and green slash... or blank like Norman's last post?
 

 Ron

Hi Ron
On Norman's last post click on "see message history" right there under blank space where you would expect the message to be and it should then appear, his links to NBC news article.
Kone

Hi Ron
In Norman's last "ground loop" titled post , you need to scroll down a bit and click on " show all 4 messages in this topic" and you can read what Norman wrote at bottom.message in the list of four, with Hectors turd that won't flush at top of the list
Kone

Iron, photo came back from Yahoo intact and visible!!?? ???

On 7/1/2019 10:00 AM, [email protected] [EVGRAY] wrote:
>
> Ole,
>
>
> How do you send a photo? I have never been able to do that in Yahoo.
> It always comes out with the small square and green slash... or blank 
> like Norman's last post?
>
> Ron
>

That works! thanks 

 Ron
 

---In [email protected], <konehead@...> wrote :

 Hi Ron
 On Norman's last post click on "see message history" right there under blank space where you would expect the message to be and it should then appear, his links to NBC news article.
 Kone

Hi Ron
I can now  send photos if you email the group at [email protected]
And include the photo in attachment in the email
Should work fine with chrome browser could be that the microsoft explorer won't work .
Be sure to send smaler l size photos and if video, I keep it under 20 seconds and it should  come through.
Kone

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---In [email protected], <konehead@...> wrote :

 Hi Ron
 I can now send photos if you email the group at [email protected] mailto:[email protected]
 And include the photo in attachment in the email
 Should work fine with chrome browser could be that the microsoft explorer won't work .
 Be sure to send smaler l size photos and if video, I keep it under 20 seconds and it should come through.
 Kone