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#1 Is In!

A project log for 52 Boards

1 PCB a week for a year.

morganmorgan 07/14/2020 at 18:412 Comments

Alright! The first boards shipped last Friday and as expected arrived here on Monday. Sadly, I missed the Friday Digikey window..... so parts wont' arrive until Wed/Thur at best. Anyhow, the boards look great as expected and of course as soon as I revisited the design files I spotted a mistake. I guess this is expected when you try to last second whack a second ill thought through circuit into a design. Thankfully, the amplifier itself still looks good but I made a huge mistake on the laser diode portion of the circuit. Not only did I misread the datasheet for the worlds cutest laser diode, at some point I accidentally assigned the MOSFET footprint to be a 0603 resistor. Womp.

IMMA LASER!

Two pin transistor eh? Not only that, but the circuit layout is straight up wrong. So I think one of two (or both) things happened, I started with the diode on the high-side and then swapped it with the resistor making it low-side, while also over zealously selecting selecting the MOSFET while assigning the resistor footprints.


Thankfully this is all very bodgeable and taught an important lesson, neither DRC or ERC will catch this kind of mistake. I'm keeping an eye on shipping for now, with a bit of luck it will arrive Thur, with a lot of luck tomorrow when I'll actually have time to build. Regardless next update on this one won't be until next week.

Discussions

Simon Merrett wrote 07/16/2020 at 19:57 point

Take your time - I'm still looking forward to finding out what this build can do. 

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morgan wrote 07/21/2020 at 17:42 point

Thankfully as it wasn't the main part of the circuit it's not that big a deal. I've build the first one but didn't quite get results I would have expected. At a quick glance, I'm getting ~70-150kHz noise of 1-5ms square waves. I've just got back from a short trip and hope to check it out more in the next couple days.

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