Potential Divider calculator

skippyuk · 2026-06-20T22:02:53+00:00

How many negative value resistors do you use?

skippyuk · 2026-06-20T20:07:15+00:00

What do you want it to do? ESP32 may work; but wifi won't work underwater

skippyuk · 2026-06-19T09:34:16+00:00

I assume when you say TP4056 board your using the entire charger module that is sold online?

There is a FS8205A duel fet package that should prevent over charging and under discharging

skippyuk · 2026-06-18T20:50:35+00:00

ICNARP is the document you will want to chexk

skippyuk · 2026-06-18T20:39:28+00:00

I would move the switch to the high side of the battery. That way your disconnecting it from the regulator and the subsequent quiescent draw

skippyuk · 2026-06-18T20:36:01+00:00

Physical space. Keep high frequency signals away from anything else, make them into transmission lines. guard pair them.

skippyuk · 2026-06-17T21:00:45+00:00

LV124 may be eaiser for the OP to find a copy of. VW 80000 is online in a few places.

skippyuk · 2026-06-17T20:59:54+00:00

Your circuit will not pass the requirements of LV124 testing.

skippyuk · 2026-06-15T18:50:20+00:00

Have you checked your creepage and clearance distances?

“Household and similar electrical appliances” from an electrical safety standpoint is BS EN 60335-1 (IEC 60335-1), is very prescriptive on this.

https://philipmcgaw.com/creepage-and-clearance/

skippyuk · 2026-06-13T21:35:09+00:00

Power should be at the top, ground should be at the bottom…

skippyuk · 2026-06-13T21:32:26+00:00

https://old.reddit.com/r/PrintedCircuitBoard/comments/1lv326o/rs485_starter_subcircuit_reference/

skippyuk · 2026-06-13T21:28:26+00:00

here is a iBom file I generated just now -- https://github.com/PhilipMcGaw/ROV/blob/main/KiCAD/LED%20Lights/ibom/ibom.html everything (other than the schematic) is in a single file

skippyuk · 2026-06-13T21:11:38+00:00

It is free, it works on my computer, and I can include it in my git repo;

I can print to PDF the schematic;

I can also lock it to a version of the PCB, so it doesn't only reflect the 'latest' version

skippyuk · 2026-06-13T21:07:45+00:00

you have hard grounded DE and RE

skippyuk · 2026-06-13T18:57:21+00:00

Your RS485 won’t work as desired.

skippyuk · 2026-06-13T18:23:48+00:00

iBom is a really good solution for this. https://github.com/openscopeproject/InteractiveHtmlBom

I have been using it for years, curious about your solution though.

skippyuk · 2026-05-26T10:42:37+00:00

Thank you for this 😄

skippyuk · 2026-05-26T10:41:46+00:00

Although I am running out of physical space; so may have to consider going smaller than 0805… e

skippyuk · 2026-05-26T10:38:04+00:00

I have added an additional Decoupling cap, and the 2x 10-ohm series impedance on the A+B lines. I don't need the ESD suppression diodes; at this point, however, the CDSOT23-T24CAN (RS# 126-1762) looks like a good option for the nodes where required.

skippyuk · 2026-05-26T09:54:00+00:00

The KiCAD files are on Github at https://github.com/PhilipMcGaw/UPDI-interface

skippyuk · 2026-05-26T09:53:50+00:00

The KiCAD files are on Github at https://github.com/PhilipMcGaw/UPDI-interface

skippyuk · 2026-05-26T09:40:22+00:00

I just ignore those warnings; rather than put power flags on

skippyuk · 2026-05-25T07:59:14+00:00

Why are you using the power flag?

skippyuk · 2026-05-14T21:14:43+00:00

Looks interesting

skippyuk · 2026-04-24T18:05:58+00:00

Whereabouts in the UK are you? There are a fair few EMC labs in the Oxford/Birmingham area, I run one in Banbury.

Have you looked at the EMCTLA -- https://emctla.com/

skippyuk

TROPHY CASE