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Photodiode in a tube

We plan to put a photodiode and electronics into a deep-drawn aluminum tube, but delivery on the Zero can is 7 weeks, so my production manager/ME/machinist made this mockup. The body is a thin-wall brass tube with a flat piece brazed on to make the end cap. Without a magnifier, you (or at least I) can't even see the seam.

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Electronics design is about half packaging. All The Brat has got to do now is jam two pages of schematic onto that board, optimistically one side of it.

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John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
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Reply to
John Larkin
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On a sunny day (Tue, 29 Oct 2013 09:05:51 -0700) it happened John Larkin wrote in :

What is the round hole next to the ethernet connector for?

Reply to
Jan Panteltje

That will have a PEM-like threaded insert for a screw, securing the tube into a structure. It will be a swaged thing, since the metal is too thin for a proper PEM insert.

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John Larkin                  Highland Technology Inc 
www.highlandtechnology.com   jlarkin at highlandtechnology dot com    

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom timing and laser controllers 
Photonics and fiberoptic TTL data links 
VME  analog, thermocouple, LVDT, synchro, tachometer 
Multichannel arbitrary waveform generators
Reply to
John Larkin

Agreed.

A square photodiode and square connector sorta suggest that a rectangular can might be more appropriate. A rectangular can should give you room for two PCB's and more volume if necessary.

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Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

Looks nice, Say where do you get your photodiodes? We buy something that looks similar from Opto-electronics.. but they are spendy. (Pin-3cd ~$8.00 pin-44D ~$20.00 pin-6d... I've got these in my box but can't find what we paid for them.)

George H.

Reply to
George Herold

The customer wants a round tube. Actually, it looks like things will fit. I'll post pics of the real thing when it's done.

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John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation
Reply to
John Larkin

I don't want to talk details about the electronics. NDAs and all that. But the photodiode isn't cheap. It's going to cost more than the enclosure.

I just thought the packaging looked cool. I think we'll gold plate the outside surface of the round board to make it look cooler.

Is gold alodine illegal now? That would look nice on the aluminum can, but may involve cadmium.

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John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation
Reply to
John Larkin

Very nice mockup.

It's still available, with modified processes. Chromate finish is used a lot on aircraft stuff. You don't like plain old anodize?

Reply to
Spehro Pefhany

I'd rather keep everything conductive. That RJ, for example, has spring fingers that ground it to the hole. Alodine is cheaper, too.

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John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation
Reply to
John Larkin

Very nice. Looks like it could fit in a telescope eyepiece.

Reply to
Spehro Pefhany

Den tirsdag den 29. oktober 2013 17.39.07 UTC+1 skrev John Larkin:

maybe something like this:

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-Lasse

Reply to
Lasse Langwadt Christensen

Jan Panteltje used his keyboard to write :

A standard PEM will pull out. The tube length is a great lever arm: vibration, etc will do it.

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Reply to
OldGuy

Those would be really cool, for attaching the internal PCB to the can. We wanted to use them but they're too big.

The swage thing is used for the screw that attaches the can to a structure:

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John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation
Reply to
John Larkin

Den tirsdag den 29. oktober 2013 22.32.10 UTC+1 skrev John Larkin:

With that soldered to the pcb you would only need a hole in the can With the nut flush against the inside of the can it wouldn't be the pcb that takes any force it just holds the nut in place

-Lasse

Reply to
Lasse Langwadt Christensen

I think the dimensions didn't work out for that. The RJ45 connector is hogging all the space where that PEM would sit. The swage thing is nice, less potential PCB stress if the PEM weren't exactly vertical, no force on the board if some tech scrunches the screw down.

But I'm just the circuit designer. My mechanical guy worked out all the gory 3D details.

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John Larkin         Highland Technology, Inc 

jlarkin at highlandtechnology dot com 
http://www.highlandtechnology.com 

Precision electronic instrumentation 
Picosecond-resolution Digital Delay and Pulse generators 
Custom laser drivers and controllers 
Photonics and fiberoptic TTL data links 
VME thermocouple, LVDT, synchro   acquisition and simulation
Reply to
John Larkin

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