PCBway – Part 2: Universal parts for non universal projects

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PCBway – Part 2: Useful, simple things you’ll actually use

Here is part 2 of the PCBway board order.
As stated in the previous post, I made several boards. Simple does not mean stupid. I realized that I sometimes spend a lot of time building the same things over and over when building or restoring old electronics, so I when Emily at PCBway got in touch with me, I made a few boards that could ease my future repairs and restorations.

Universal rectifier boards

Universal rectifier boards and the components they repladed

First up: rectifier boards.

I build and repair a lot of equipment, both high voltage stuff, and lower <24 V.

A lot of older gear contains selenium rectifiers, which I like to replace with silicon.

So instead of hacking together diode bridges in mid-air every time, I designed two universal rectifier PCB's. The larger is stackable, or rather possible to series connect to increase voltage handling, up to 1800V for two boards. The smaller board is just a full wave rectifier. Nothing complicated, just something clean, repeatable, and easy to mount.

I also played around with panelization using mousebites. Mainly to test it for future designs where it might be a good idea to squeeze together many designs on one board.

Crisp mousebites, easy to break apart


Small but important note if you’re doing the same:
If you electrically tie the designs together (even with something as simple as a copper link), board houses probably treats it as a single design.

Real-world use

Here’s one of those rectifier boards installed after removing the original selenium stack from my 1950s AM "SM5RM" transmitter. 
A bonus that I did not plan, was that the board was compatible with choke input power supplies, thanks to the extra series, or stack connections.
Perfect example where a universal board like this saves time (and space).

Before, selenium bridge rectifier with C-L-C filtering. On the right is another selenium stack 

Here the selenium is replaced with FR4 and silicon. It was not planned during the design phase,
but it was possible to configure the board to accomodate C-L-C filtering as well. 

Junk heading towards the electronics recycling,




Tiny adapter / header boards

Next thing: small universal pin header boards.


Hall sensor position encoder with an adapter board soldered to the pins, instead of using 
dupont connectors. Solid!

These turned out to be useful.

I tend to do a lot of prototyping and semi-permanent stuff using breakout boards and pin headers. A lot of times, it feels good to ditch dupont wires, and instead solder wires to boards instead, so for this order, I also made some small adapter boards. Just 2.54mm spaced, through hole pads, for easy connection of wires.

Honestly, this is the kind of stuff you should just order in bulk and treat like consumables. Same category as resistors and zip ties. 

With my next order, I'm going to make a board layout, with adapters, 2.54-2.54, 2.54-5.08, multi pin, mouse bite separated, all of them sharing one trace for them to be treated os one design.

Voltage divider boards 


Here is the populated board with 500V applied to the input terminal



Since I build a lot of high voltage supplies, I also made a dedicated voltage divider board.

The idea is simple:

Divide the voltage down to a value that is safe to read with a multimeter or a meter of some kind.

This one is populated for 5 kV, with a ratio of 1000-1, meaning that 5000 V in, turns to 5 V on the output.

Main use cases:

  • feeding scaled voltage into Arduino ADC
  • checking HV with a normal multimeter
  • acting as a fixed divider for HV probe setups

Way safer than improvising something on a piece of perfboard when you’re sitting on a few kilovolts.

This is the populated metering board. Be sure to use resistors that can whitstand the voltage. I'm using Vishay VR37 series HV resistors for the top of the divider. Due to tolerances, this divider turns out to have a 1008:1 ratio. For 3000 V in, the divided voltage read by a voltmeter would show 2.976 V. If used with an microcontroller for measuring, this is calibrated in software, but in reality, this is good enough for all my measurments.


Here is the board with about 5000 volts applied to the input port. 

About PCBway (since… well… this is that post)

I’ve used PCBWay for a while now, and this batch was exactly what you want from a board house:

  • Boards showed up straight and clean
  • Mousebites snapped exactly as expected
  • Silkscreen and drill alignment were spot on
  • No weird surprises in plating or finish
  • Easy checkout, fast shipping and reasonable prices
  • They even added a few extras of the small boards, likely to fill a panel. Appreciated. 


Conclusion

I can totally recommend PCBway, and will use them next time as well.

Even though this is a hobby of mine, and time is not an issue, these are the boards that save time the right way.





73, Tommy


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