SG8 Pot location

[RS_]

Hi,

Go back to your caps in a sq arrangement with all the
TOxxxx parts in a row so they fit on a single heat sink like you had it.

Make fat traces on the bottom on both sides of the Mosfets.

Arrange the voltage divider resistors to have that connection as close to the Gate as possible, that means using the resistor to jump over a Fat trace, or onto a Fat trace, and keeping all traces on the bottom side....
Spread out the mosfets, (1in centers) and make that connection trace between the mosfets in a straight line to the gate.
keep the resistors up off the PCB 1/8in or so when soldering them in

In general, arrange all components, to keep all traces as short as possible through out the circuit...

Make sure you have enough room for mounting holes in the corners.

[claudio]

Hi,

Go back to your caps in a sq arrangement with all the
TOxxxx parts in a row so they fit on a single heat sink like you had it.

Make fat traces on the bottom on both sides of the Mosfets.

Arrange the voltage divider resistors to have that connection as close to the Gate as possible, that means using the resistor to jump over a Fat trace, or onto a Fat trace, and keeping all traces on the bottom side....
Spread out the mosfets, (1in centers) and make that connection trace between the mosfets in a straight line to the gate.
keep the resistors up off the PCB 1/8in or so when soldering them in

In general, arrange all components, to keep all traces as short as possible through out the circuit...

Make sure you have enough room for mounting holes in the corners.

Hi RS_, John, Faraday88,

please just check the Mofset part, PCB is not finished, I would like to know if the traces are better now before reducing the empty space.
Mofsets distance 1in, maybe too much ?
Of course will put holes to mount the PCB.
Will place the POT part on the bottom.
I do not see how to draw everything on 1 side.
Is this what you mean to keep traces on the bottom side of the resistors ?

again thank you all for the help
regards

PCB_PCB-man-4Mofset-invertiti_20180510110250.pdf

[RS_]

That looks better....

move the TIP41 output trace to very bottom below the fat trace, and the resistors from that trace will jump over the fat trace to the gate

move the other resistors so that they jump from the top fat trace, next to the Gates and the other resistor pads, and make that pad connection to the gates pad and other resistors pads.....

move the 7812 over between the TIP42 and the mosfets....

move the opto to right in front of the TIP42

[claudio]

That looks better....

move the TIP41 output trace to very bottom below the fat trace, and the resistors from that trace will jump over the fat trace to the gate

move the other resistors so that they jump from the top fat trace, next to the Gates and the other resistor pads, and make that pad connection to the gates pad and other resistors pads.....

move the 7812 over between the TIP42 and the mosfets....

move the opto to right in front of the TIP42

...like this ?
We're getting closer...

PCB_PCB4Mofinv2_20180511100404.pdf

[RS_]

Yep, getting closer.....

Make the resistors pad spacing smaller, and move the top fat trace closer to the Mosfets like the bottom fat trace is.

move the 2 resistor pair's to right next to their mosfet gates. Adjust where the 2 V resistor divider pads land, to be just to the right of the Gate pads and make a straight connection between the 3 pads on the bottom of the PCB.
once again move the 7812 to between the TIP42 and the mosfet.

you might want to rotate that line of TO parts 90deg to be vertical on the right side so you have real short connections from the caps to the mosfets and connectors

[claudio]

Yep, getting closer.....

Make the resistors pad spacing smaller, and move the top fat trace closer to the Mosfets like the bottom fat trace is.

move the 2 resistor pair's to right next to their mosfet gates. Adjust where the 2 V resistor divider pads land, to be just to the right of the Gate pads and make a straight connection between the 3 pads on the bottom of the PCB.
once again move the 7812 to between the TIP42 and the mosfet.

you might want to rotate that line of TO parts 90deg to be vertical on the right side so you have real short connections from the caps to the mosfets and connectors

Check this one...
1. all the caps part on one PCB side (!)
2. TO on the same line to install heat sink
3. holes placed

Questions:
1. is it ok connect the pos of 7812 directly to the 1/3 connector ?
2. is it ok connect the neg of 7812 directly to the IRPF260 near on the right ?
3. the resistors over the mofsets are ok (esp the lat one)?
4. is it ok tho connect the 1N914 directly to the 4N35M ? (much shorter way)
5. spacing between the TO enough ?

more space could be saved but I think we are almost there...

PCB_PCB4Mofinv3_20180512174841.pdf

[RS_]

much, much better.....

1. is it ok connect the pos of 7812 directly to the 1/3 connector ?
Yes, but it can be connected to the cap... see below why....

2. is it ok connect the neg of 7812 directly to the IRPF260 near on the right ?
Yes

3. the resistors over the mofsets are ok (esp the lat one)?
Last one is Ok
Can you chose a Resistor Pad spacing component that is smaller...? If so, than you can tighten up all the trace spacing's around the Mosfets... All of the resistor Pad spacing's need to be made smaller, they are just too wide for the size of 1/4W resistors.......

4. is it ok tho connect the 1N914 directly to the 4N35M ? (much shorter way)
Yes and make this diode a 2-3 amp diode, that 1N914 is not big enough..

5. spacing between the TO enough ?
Add a little space between the Tip42 and the 7812, and the mosfet next to it. 1in centers is always a good spacing if you have the room

make the short traces that connect the Source and Drain to the long fat trace, smaller and make the pad size larger, to match the trace. This short trace only carry's the current for that one Mosfet not all 4.
Rearrange the traces on the cap, so that both connectors are on the right side of the PCB. make the very top cap traces close to the mosfets

Make all Pads and holes bigger, and the traces the same width as the pads.....

[claudio]

1. is it ok connect the pos of 7812 directly to the 1/3 connector ?
Yes, but it can be connected to the cap... see below why....
done, better directly to the pos of the cap ?

2. is it ok connect the neg of 7812 directly to the IRPF260 near on the right ?
Yes
done

3. the resistors over the mofsets are ok (esp the lat one)?
Last one is Ok
Can you chose a Resistor Pad spacing component that is smaller...? If so, than you can tighten up all the trace spacing's around the Mosfets... All of the resistor Pad spacing's need to be made smaller, they are just too wide for the size of 1/4W resistors.......
ok done, I hope I get right what you mean.. I have carbon resistors 1k, 2k, 330ohms at 1/2W, are they ok or should I get the 1/4W ?

4. is it ok tho connect the 1N914 directly to the 4N35M ? (much shorter way)
Yes and make this diode a 2-3 amp diode, that 1N914 is not big enough..
ok done, I have 6A10-TP 1000V 6A, is it ok ?

5. spacing between the TO enough ?
Add a little space between the Tip42 and the 7812, and the mosfet next to it. 1in centers is always a good spacing if you have the room
ok done, I feel adding more space would make the PCB too wide, but if you say it must be 1in center I will do exactly 1in.

make the short traces that connect the Source and Drain to the long fat trace, smaller and make the pad size larger, to match the trace. This short trace only carry's the current for that one Mosfet not all 4.
Rearrange the traces on the cap, so that both connectors are on the right side of the PCB. make the very top cap traces close to the mosfets
ok done, but I think that if we want to keep the caps part on 1 side of the PCB it's impossible to put all the pads on the right.
I could make the traces around the caps and the Mofsets a little wider, should I do it ? Maybe better anyway to connect them with 8 or 12 AWG wire ?
adjusted the traces at same size of pads
Pads are (bought them) https://www.mouser.it/ProductDetail/534-8191 I would prefer to use them instead of the screws...

Make all Pads and holes bigger, and the traces the same width as the pads.....
like this ok ?


PCB_PCB4Mofinv3_20180513103411.pdf

[RS_]

Hea,

Move the 1/3 screw terminal over to the left side of the PCB, and rearrange the cap traces, and move the caps a little closer to the mosfets, You want all screw terminals close to the edge of the PCB for ease of use. If they are in the interior of the PCB, they are hard to get to......

Once again, make all Pads and Holes larger, Beefier, easier to work with....
If you happen to have parts with bigger leads, they will then fit, and not be a PIA..... Experience talking here, the standard issue small pads and holes on all the components, suck for a verity of reasons...... 1/2W resistors should be ok vs 1/4W, and should fit that Pad spacing, but will need the bigger holes.
Swap out all the other resistor Component Spacing's.

You should be able to make all the other Top side red traces on the bottom side, then a One Sided PCB will be much cheaper to make. Remember that Traces can be run under a resistor between it's pads....

Move the Opto to directly in front of the TIP41.
Rotate the 555 section 90deg so that the 555 is facing the opto and the Screw Terminals are on the bottom close to the edge.
Check the Pot's connections to be sure one connection is on the wiper, and not just across the full resistance, as usually the wiper is the middle connection on a pot....
A 6 amp diode is over kill, and will have Very Fat leads that will be way bigger than the pad holes, and a pad spacing much bigger than the 1n914 or a 1-2 A diode....

[claudio]

Hea,

Move the 1/3 screw terminal over to the left side of the PCB, and rearrange the cap traces, and move the caps a little closer to the mosfets, You want all screw terminals close to the edge of the PCB for ease of use. If they are in the interior of the PCB, they are hard to get to......

Once again, make all Pads and Holes larger, Beefier, easier to work with....
If you happen to have parts with bigger leads, they will then fit, and not be a PIA..... Experience talking here, the standard issue small pads and holes on all the components, suck for a verity of reasons...... 1/2W resistors should be ok vs 1/4W, and should fit that Pad spacing, but will need the bigger holes.
Swap out all the other resistor Component Spacing's.

You should be able to make all the other Top side red traces on the bottom side, then a One Sided PCB will be much cheaper to make. Remember that Traces can be run under a resistor between it's pads....

Move the Opto to directly in front of the TIP41.
Rotate the 555 section 90deg so that the 555 is facing the opto and the Screw Terminals are on the bottom close to the edge.
Check the Pot's connections to be sure one connection is on the wiper, and not just across the full resistance, as usually the wiper is the middle connection on a pot....
A 6 amp diode is over kill, and will have Very Fat leads that will be way bigger than the pad holes, and a pad spacing much bigger than the 1n914 or a 1-2 A diode....

Hi RS_,
I hope I get your indications correctly...
please quickly check the connections, spacing rearrangement must be done...
1. can I connect to the CAPS N.1/3 pad and N.2 pad like this ?
2. pots connections are ok now? My drawing followed the EasyEda software indication...
3. routing around 555 ok ?
4. pad 6: do not see how to put it on the edge on the same PCB route side...
5. I found this 3A diode https://www.mouser.it/ProductDetail/...ZlhM6bLg%3d%3d
6. will adjust holes, pads and spacing after I am sure the connections are ok, just to save time...

If connections are ok then everything is on one side !

again... thanks for your patience

PCB_PCB4Mofinv4TRIS_20180517113236.pdf

[RS_]

1. can I connect to the CAPS N.1/3 pad and N.2 pad like this ?

That looks ok, I would move the 1/3 pad to in between the caps where the 2 pad is. Move the 2 pad over close to the 4 pad by the PCB hole, shift the whole thing up and move the PCB hole to the corner. Rotate the Caps and traces 90deg to the right for better shorter connections to the Screw pads, and to the Source fat trace.
The long trace from the 1/3 pad would be better coming from the lowest cap close to the 7812.

2. pots connections are ok now? My drawing followed the EasyEda software indication...

On the Pots, if you have the pot you are going to use, measure the resistance to see which of the 3 leads is the adjustable wiper, and then design the PCB to match that.....
Make sure the pot Component pads are in the correct spacing/location for the pot you are going to use.

3. routing around 555 ok ?

I would move the 555 timer as close to the opto as you can, about where the 6 Screw pads is now, and then design all the other parts around that location with as short of traces as possible...

4. pad 6: do not see how to put it on the edge on the same PCB route side...
A rearrangement should allow you to have both pads along the edge
A size bigger Cap Component pads spacing will help too.

5. I found this 3A diode https://www.mouser.it/ProductDetail/...ZlhM6bLg%3d%3d
will work, but i would buy 1N5408 part number so you can also use them as SSG output diodes too....

6. will adjust holes, pads and spacing after I am sure the connections are ok, just to save time...

OK

[claudio]

1. can I connect to the CAPS N.1/3 pad and N.2 pad like this ?

That looks ok, I would move the 1/3 pad to in between the caps where the 2 pad is. Move the 2 pad over close to the 4 pad by the PCB hole, shift the whole thing up and move the PCB hole to the corner. Rotate the Caps and traces 90deg to the right for better shorter connections to the Screw pads, and to the Source fat trace.
The long trace from the 1/3 pad would be better coming from the lowest cap close to the 7812.

2. pots connections are ok now? My drawing followed the EasyEda software indication...

On the Pots, if you have the pot you are going to use, measure the resistance to see which of the 3 leads is the adjustable wiper, and then design the PCB to match that.....
Make sure the pot Component pads are in the correct spacing/location for the pot you are going to use.

3. routing around 555 ok ?

I would move the 555 timer as close to the opto as you can, about where the 6 Screw pads is now, and then design all the other parts around that location with as short of traces as possible...

4. pad 6: do not see how to put it on the edge on the same PCB route side...
A rearrangement should allow you to have both pads along the edge
A size bigger Cap Component pads spacing will help too.

5. I found this 3A diode https://www.mouser.it/ProductDetail/...ZlhM6bLg%3d%3d
will work, but i would buy 1N5408 part number so you can also use them as SSG output diodes too....

6. will adjust holes, pads and spacing after I am sure the connections are ok, just to save time...

OK

Hi RS_
2. Pots section..
the pots spacing/holes fit perfectly for the pots I got (mouser 652-PDB12-M4251105BF)
this is the scheme of the pots

please tell me how should I connect them, I put numbers and letters ...


rearranged PCB following indications... routing and spacing still to manage..
PCB_PCB4Mofinv4TRIS_20180519092849.pdf

ordering the 1N5408 Diodes.

regards

[RS_]

pot pins 1 and 2, and that looks like what you have now.....

your cap and trace rearrangement looks real good

[claudio]

pot pins 1 and 2, and that looks like what you have now.....

your cap and trace rearrangement looks real good

Now I have 1A, 2B, 5C, 6D. Is that the correct one ?
Just to be sure...



PCB updated ...
will re-check connections and holes
will try the circuit on bread board first...
pots section ok ?
PCB_PCB4Mofinv4TRIS_20180520111403.pdf

[RS_]

If you hook the right pot up like that, it will operate backward from the other pot