New Bipolar Boost TX and Front End

[Mdtoday]

JL, I have been working on another option for this particular enclosure, its not developed fully for this particular design but is the general layout I use for my power sources albeit with different circuits.

Battery holder one side, power supply and protection on the other.





I still have the full discrete wire version as per last post as I do understand your modular approach but thought I would put this forward as another option for this particular enclosure.

I envisaged a single row header friction lock 4 or 6 pins mounted on the rear of the PCB with a cutout into the main enclosure.
If a 6pin connector is used, this would carry Gnd, +20, +5, +3v , Bat+, SW Bat+.
If a 4 pin connector is used then just Gnd, +20, +5, +3v.

If the 4 x support pillars in the enclosure were moved to corners of the PCB, this may give enough space to include the coil switch circuit, a cut-out in the rear wall to account for the relay height would be required.

The cost of the board would be minimal, a little less wiring

Just a thought for this enclosure

[Mdtoday]

Connector placed on PCB , mating to female inline wire tail connector.

Position shown can be changed to right hand side looking from front of enclosure, depends on position of power switch

[KingJL]

JL, I have been working on another option for this particular enclosure... The cost of the board would be minimal, a little less wiring... Just a thought for this enclosure

The more I think about this, the more I like it. It may also be a convenient/logical place for this minimal circuit that is required for Pin Point.

I was going to include it with the probe switch circuit, but was not really satisfied with that approach as not all would wish to include the probe circuit. But the PP switch is required in all configurations and so is power. It only requires 2 resistors and 3 connection pins (3.3V to PP switch, PP switch to pull down(junction of R1 & R2), and a connection for Pmod j4 pin 7 to current limiting resistor(R1)).

[Mdtoday]

Power PCB Option1

The more I think about this, the more I like it. It may also be a convenient/logical place for this minimal circuit that is required for Pin Point.

I was going to include it with the probe switch circuit, but was not really satisfied with that approach as not all would wish to include the probe circuit. But the PP switch is required in all configurations and so is power. It only requires 2 resistors and 3 connection pins (3.3V to PP switch, PP switch to pull down(junction of R1 & R2), and a connection for Pmod j4 pin 7 to current limiting resistor(R1)).

Thanks for the info, sounds like a good option, I have attached a Kicad project showing the board outline, modules and keep-out areas around battery holder mounting pillars.
The PCB and module size are correct 1:1 however I have yet to draft the battery holder library and recheck libraries, had family over today.

[green]

Could someone help could not open include file "spdt . sub" what do I need to do? Tried to open .sub file, don't know what to do with it. Why do I have to reenter all my pass words after clicking on a .sub file? Not a computer person.

Change the extension from .txt to .sub. You never want to double click a .sub (or a .mod or lib file for that matter). If you want to view the contents right click and select "open with" and the select a suitable editor (notepad, worpad, etc.). Put the .sub file in the working directory of your current schematic or put it in the "LTSPICE".../lib/sub directory.

NOTE: the spdt.sub file was included in the zip of post #4 of this thread from reply#62

Thanks for the reply. Still haven't figured it out. Why aren't the switches drawn on the schematic? Apologize for the questions, computers and I don't speak the same language.

[KingJL]

... Hope to have all menus and menu items working by the end of the week...

Well, I did not meet my goals for the week. I seem to have created a problem somewhere in my hardware definition (probably when I updated the TX_RX ip to sync changes in the status register and the parameter register set) where i am not generating interrupts from the TX_RX module or that microblaze is for some reason not acting on them. All other interrupts are working properly. Vivado sometime does not pull in all of the required pieces when an ip is modified and is difficult to get the issue corrected. I am going to have to become familiar with the Vivado/Xilinx Integrated Logic Analyzer (ILA) to see if I can pinpoint the issue. I want to sort that out before I forge ahead.

[KingJL]

@Mdtoday, What version of Vivado did you download and install (2018.2, 2018.3, 2019.1, etc)? I am thinking of migrating to 2019.1... it has some advanced features that come standard with the webpack license that are extra cost items with 2018.3 and below. Partial reconfiguration being one. Also i suspect a few quirks of 2018.3 have been quietly fixed!

[Mdtoday]

@Mdtoday, What version of Vivado did you download and install (2018.2, 2018.3, 2019.1, etc)? I am thinking of migrating to 2019.1... it has some advanced features that come standard with the webpack license that are extra cost items with 2018.3 and below. Partial reconfiguration being one. Also i suspect a few quirks of 2018.3 have been quietly fixed!

Version 2018.3 JL, I'll check out the 2019.1 version, thanks for the heads up.

[Mdtoday]

I have been busy on the power supply PCB layout for the posted enclosure design.
Still some tidy-up work to do on it, mainly the library inclusions and ground pours. I will post KiCad files later tomorrow.

[KingJL]

Looking fantastic!!

[Mdtoday]

Looking fantastic!!

Thanks JL, getting there.
I noticed a small problem with using the MT3608 modules, reading the specs, they are only a boost mode device, I thought they were buck/boost.
I don't have delivery of my modules yet, so I can't test.
I had thought the batteries would be in series ~7.2v which is fine for the 20v but while drawing up the layout, I thought I would check the device specs and noticed the Boost only mode.
This would mean the 5 and 3v3 would not work on 2 series connect cells (I think anyway)
If this is the case, then we can simply use 2 x 18650 in parallel ~ 3.6-4v output and put a diode in series with the module used for 3v3 output.
As I say, I don't have my modules yet so can't check and maybe I've missed something but best to ask the question...

Cheers

Mdtoday

[KingJL]

Thanks JL, getting there.
I noticed a small problem with using the MT3608 modules, reading the specs, they are only a boost mode device, I thought they were buck/boost.
I don't have delivery of my modules yet, so I can't test.
I had thought the batteries would be in series ~7.2v which is fine for the 20v but while drawing up the layout, I thought I would check the device specs and noticed the Boost only mode.
This would mean the 5 and 3v3 would not work on 2 series connect cells (I think anyway)
If this is the case, then we can simply use 2 x 18650 in parallel ~ 3.6-4v output and put a diode in series with the module used for 3v3 output.
As I say, I don't have my modules yet so can't check and maybe I've missed something but best to ask the question...

Cheers

Mdtoday

so far in all of my projects, I have only used them with 3 and 4.5 volt inputs... and I had not yet used them to generate 3.3V.,, it was always 5V and higher. I probably need to hook one up and test for generating 3.3V.

[Mdtoday]

so far in all of my projects, I have only used them with 3 and 4.5 volt inputs... and I had not yet used them to generate 3.3V.,, it was always 5V and higher. I probably need to hook one up and test for generating 3.3V.

Thanks, that makes sense, I should receive the order of MT3608 modules in a day or two and can check, if you are busy with code.

[Mdtoday]

On the Power PCB my thoughts are to include UV/reverse polarity protection circuits for each 18650 cell to prevent any nasty problems occurring.
Probably using something like the TI BQ279700, Seiko S-8200 or Fortune DW01-P devices.
It adds cost but with Li power cells, safety is always a concern.

[Mdtoday]

On the Power PCB my thoughts are to include UV/reverse polarity protection circuits for each 18650 cell to prevent any nasty problems occurring.
.

Here is a draft of cell protection circuit, It's a work in progress

IC1 and IC2 along with Q1,Q2 respectively provide the protection for each 18650 cell.
D1 and D2 provide the reverse polarity protection in case either battery is inserted the wrong way.
This will cause the UV/OV points to move but I think this can be corrected somewhat by inserting a voltage divider in place of R3 and R4
D3 and D4 provide the isolation for each protection circuit.
D5 + D1/D3 or D2/D4 in series should drop the voltage enough to the MT3608 module U3 to work at a lower voltage required to boost up to 3v3... it's not tested yet so we will see once I get delivery of some modules...

D3, D4,D5 may have to be standard diodes to get the required voltage drop to U3

The MT3608 modules work down to 2v

Additional cost of the protection circuit is around $4-$5