two switcher circuits

[TTman]

https://www.dropbox.com/s/wxerjg36c3ow8s5/J744_3.jpg?dl=0

https://www.dropbox.com/s/lnn1jwk7gm1h713/J744_2.jpg?dl=0

The idea is to get away from the boring Hammond boxes. This is a
semi-custom extrusion with nice grounding and thermals. We plan to
laser blast the anodize for external artwork.

Be careful if you have to clean the board with those pots... we had
horrendous problems until we figured out the issue...

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

 

On Sat, 4 Apr 2020 14:02:08 +0100, TTman <kraken.sankey@gmail.com>
wrote:

https://www.dropbox.com/s/wxerjg36c3ow8s5/J744_3.jpg?dl=0

https://www.dropbox.com/s/lnn1jwk7gm1h713/J744_2.jpg?dl=0

The idea is to get away from the boring Hammond boxes. This is a
semi-custom extrusion with nice grounding and thermals. We plan to
laser blast the anodize for external artwork.


Be careful if you have to clean the board with those pots... we had
horrendous problems until we figured out the issue...

We haven't had problems with these Bourns pots, with aqueous or
solvent cleaning. Some companies absolutely forbid trimpots. Sometimes
they are just what you need.

We did have horrible cleaning problems with some relays.

https://www.dropbox.com/s/2avvklzwtzc8rz4/P951_E1.JPG?raw=1






--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Michael Terrell]

On Saturday, April 4, 2020 at 10:42:52 AM UTC-4, jla...@highlandsniptechnology.com wrote:

On Sat, 4 Apr 2020 14:02:08 +0100, TTman <kraken.sankey@gmail.com
wrote:



https://www.dropbox.com/s/wxerjg36c3ow8s5/J744_3.jpg?dl=0

https://www.dropbox.com/s/lnn1jwk7gm1h713/J744_2.jpg?dl=0

The idea is to get away from the boring Hammond boxes. This is a
semi-custom extrusion with nice grounding and thermals. We plan to
laser blast the anodize for external artwork.


Be careful if you have to clean the board with those pots... we had
horrendous problems until we figured out the issue...

We haven't had problems with these Bourns pots, with aqueous or
solvent cleaning. Some companies absolutely forbid trimpots. Sometimes
they are just what you need.

We did have horrible cleaning problems with some relays.

https://www.dropbox.com/s/2avvklzwtzc8rz4/P951_E1.JPG?raw=1

We had a high failure rate wit BEC (Beckman) pots. I removed them from our AVL, and told purchasing to only buy Bourns. BEC threw a oyal hissy fit, and claimed zero defects. About six months later they blamed it on their O-ring supplier for shipping out of spec seals.

 

On Fri, 03 Apr 2020 15:23:00 -0700, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Fri, 3 Apr 2020 17:54:54 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-04-03 14:48, John Larkin wrote:
On Fri, 3 Apr 2020 13:31:31 -0400, bitrex <user@example.net> wrote:

On 4/3/2020 10:34 AM, jlarkin@highlandsniptechnology.com wrote:


https://www.dropbox.com/s/keynlhs9ktzivyh/LTM8078_dual_neg_1.asc?dl=0

https://www.dropbox.com/s/htzvrbnd8qx3ooi/LTM8078_plus_minus_1.asc?dl=0








Not a switcher, but expedient:

https://www.dropbox.com/s/uf29ubm0v1ox7pv/linear_tracking.PNG?dl=0


Driving the adj pin of a 3t regulator is an under-appreciated trick.
They are nice, cheap, thermally limited power amps.

We have standardized on 24 volt warts for small boxes, so we want to
switch mostly. So multiple outputs from tiny switchers is good.

Just minutes ago I got this:

https://www.dropbox.com/s/wxerjg36c3ow8s5/J744_3.jpg?dl=0

https://www.dropbox.com/s/lnn1jwk7gm1h713/J744_2.jpg?dl=0

My eyes! My eyes!

Get serious, I'm only running 2 mA in that LED. We were wondering how
it would look, just the led on the PCB and a hole drilled into the end
plate. The light bounces around in the hole and it actually looks
pretty good from all angles. Don't need no light pipe.


The idea is to get away from the boring Hammond boxes. This is a
semi-custom extrusion with nice grounding and thermals. We plan to
laser blast the anodize for external artwork.

Yeah, it would be good to get them to tone it down a bit.

Cheers

Phil Hobbs

I kinda like it, but some other people here don't. The Chinese seem to
like bright primary colors, and it generally looks good on them.

We're investigating getting a 20-watt n/c fiber laser to blast the
lettering in-house.

Paulo has a laser at home and he just did this:

https://www.dropbox.com/s/197eccdkrakn2ra/J744_Lasered_1.jpg?raw=1

I think we'll get one for work too.

I *think* it's a GHz o/e. I need to cobble up a really fast light
source to test it. I'm pulsing a fiber-coupled laser diode from one of
our DDGs and poking that into the o/e and I'm seeing a 500 ps
electrical output, but I don't know how fast the optical input is.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

I *think* it's a GHz o/e. I need to cobble up a really fast light
source to test it. I'm pulsing a fiber-coupled laser diode from one of
our DDGs and poking that into the o/e and I'm seeing a 500 ps
electrical output, but I don't know how fast the optical input is.

If it's out past 800 nm, you should be able to see it with an SD-48.

Cheers

Phil Hobbs

 

On Sat, 4 Apr 2020 17:19:05 -0700 (PDT), pcdhobbs@gmail.com wrote:

I *think* it's a GHz o/e. I need to cobble up a really fast light
source to test it. I'm pulsing a fiber-coupled laser diode from one of
our DDGs and poking that into the o/e and I'm seeing a 500 ps
electrical output, but I don't know how fast the optical input is.

If it's out past 800 nm, you should be able to see it with an SD-48.

Cheers

Phil Hobbs

That first unit is 850. We do have some New Focus superfast detectors
at that wavelength.

I'm thinking, for the longwave version, I can use a 10 Gbps SFP module
as a source. I'll need to get some LC-to-ST fiber cables.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

I'm thinking, for the longwave version, I can use a 10 Gbps SFP module
as a source. I'll need to get some LC-to-ST fiber cables.

SFPs are awesome--we use them for TIA tweaking.

Cheers

Phil Hobbs

 

On Sun, 5 Apr 2020 04:05:12 -0700 (PDT), pcdhobbs@gmail.com wrote:

I'm thinking, for the longwave version, I can use a 10 Gbps SFP module
as a source. I'll need to get some LC-to-ST fiber cables.

SFPs are awesome--we use them for TIA tweaking.

Cheers

Phil Hobbs

At the last minute, I hung an SFP section on my latest multi-prototype
board.

https://www.dropbox.com/s/7cx7zstt6jjnklc/Z482A.jpg?raw=1

I could slice a couple off for you if they'd be helpful.

They are telecom parts; I suspect that the laser doesn't ever go to
extinction. Gotta test that. The ac coupling time constants are all
over the place.





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

 

[Phil Hobbs]

On 2020-04-05 08:56, jlarkin@highlandsniptechnology.com wrote:

On Sun, 5 Apr 2020 04:05:12 -0700 (PDT), pcdhobbs@gmail.com wrote:

I'm thinking, for the longwave version, I can use a 10 Gbps SFP module
as a source. I'll need to get some LC-to-ST fiber cables.

SFPs are awesome--we use them for TIA tweaking.

Cheers

Phil Hobbs

At the last minute, I hung an SFP section on my latest multi-prototype
board.

https://www.dropbox.com/s/7cx7zstt6jjnklc/Z482A.jpg?raw=1

I could slice a couple off for you if they'd be helpful.

Sure, thanks. I have one of my trademark stomp boxes with pluggable
short and long wave 1.25 Gb/s modules. BTW on those ones you can hack
the coupling caps. A faster one would be very useful.

They are telecom parts; I suspect that the laser doesn't ever go to
extinction. Gotta test that. The ac coupling time constants are all
over the place.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

 

[Joe Gwinn]

On Sat, 4 Apr 2020 15:53:00 +1100, Clifford Heath <no.spam@please.net>
wrote:

On 4/4/20 3:16 pm, jlarkin@highlandsniptechnology.com wrote:
On Sat, 4 Apr 2020 10:58:32 +1100, Clifford Heath <no.spam@please.net
wrote:

On 4/4/20 7:23 am, John Larkin wrote:
On Fri, 03 Apr 2020 14:10:06 -0500, Joe Chisolm
jchisolm6@earthlink.net> wrote:

On Fri, 03 Apr 2020 11:48:20 -0700, John Larkin wrote:

On Fri, 3 Apr 2020 13:31:31 -0400, bitrex <user@example.net> wrote:

On 4/3/2020 10:34 AM, jlarkin@highlandsniptechnology.com wrote:


https://www.dropbox.com/s/keynlhs9ktzivyh/LTM8078_dual_neg_1.asc?dl=0

https://www.dropbox.com/s/htzvrbnd8qx3ooi/LTM8078_plus_minus_1.asc?
dl=0








Not a switcher, but expedient:

https://www.dropbox.com/s/uf29ubm0v1ox7pv/linear_tracking.PNG?dl=0


Driving the adj pin of a 3t regulator is an under-appreciated trick.
They are nice, cheap, thermally limited power amps.

We have standardized on 24 volt warts for small boxes, so we want to
switch mostly. So multiple outputs from tiny switchers is good.

Just minutes ago I got this:

https://www.dropbox.com/s/wxerjg36c3ow8s5/J744_3.jpg?dl=0

https://www.dropbox.com/s/lnn1jwk7gm1h713/J744_2.jpg?dl=0

The idea is to get away from the boring Hammond boxes. This is a
semi-custom extrusion with nice grounding and thermals. We plan to laser
blast the anodize for external artwork.

Who made those boxes for you? I have an upcoming project where I
need something similar.

https://www.pumay-aluminum.com/products/

Very nice.

The holes are drilled/tapped after anodize, so are conductive and
don't have the problems that the self-tappers do on the Hammond boxes.
Like metal shavings everywhere and stripped screws.

Never ever use self-tappers. They work loose with vibration, and cut new
paths when you re-insert them. You don't even need to tap if you use
trilobular (thread-forming) screws. Taptite is one brand, but it's a DIN
standard.

CH

People extrude 3/4 holes in things like this, and then use
self-tapping screws.

People don't make things to be serviced. Self-tappers can be ok in the
absence of vibration or the need to service.

The partial holes tend to break taps.

Tapping deep holes in Al is fraught - the correct technique involves
lots of reversals, and in large sizes, multiple passes with different
taps, so it's slow.

Use a forming tap, versus a cutting tap. Forming taps are very
strong, rarely break, and work very well in aluminum. Use a tapping
lubricant intended for the purpose.

..<https://www.mscdirect.com/basicsof/thread-forming-taps>

Joe Gwinn

 

[John Larkin]

On Sun, 5 Apr 2020 11:02:08 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-04-05 08:56, jlarkin@highlandsniptechnology.com wrote:
On Sun, 5 Apr 2020 04:05:12 -0700 (PDT), pcdhobbs@gmail.com wrote:

I'm thinking, for the longwave version, I can use a 10 Gbps SFP module
as a source. I'll need to get some LC-to-ST fiber cables.

SFPs are awesome--we use them for TIA tweaking.

Cheers

Phil Hobbs

At the last minute, I hung an SFP section on my latest multi-prototype
board.

https://www.dropbox.com/s/7cx7zstt6jjnklc/Z482A.jpg?raw=1

I could slice a couple off for you if they'd be helpful.

Sure, thanks. I have one of my trademark stomp boxes with pluggable
short and long wave 1.25 Gb/s modules. BTW on those ones you can hack
the coupling caps. A faster one would be very useful.

They are telecom parts; I suspect that the laser doesn't ever go to
extinction. Gotta test that. The ac coupling time constants are all
over the place.

Cheers

Phil Hobbs

Do you want a couple of these?

https://www.dropbox.com/s/yjau853aun1xvb7/Z482_SFP.jpg?raw=1

I hope I got that right!


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

[Phil Hobbs]

On 2020-04-06 15:38, John Larkin wrote:

On Sun, 5 Apr 2020 11:02:08 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 2020-04-05 08:56, jlarkin@highlandsniptechnology.com wrote:
On Sun, 5 Apr 2020 04:05:12 -0700 (PDT), pcdhobbs@gmail.com wrote:

I'm thinking, for the longwave version, I can use a 10 Gbps SFP module
as a source. I'll need to get some LC-to-ST fiber cables.

SFPs are awesome--we use them for TIA tweaking.

Cheers

Phil Hobbs

At the last minute, I hung an SFP section on my latest multi-prototype
board.

https://www.dropbox.com/s/7cx7zstt6jjnklc/Z482A.jpg?raw=1

I could slice a couple off for you if they'd be helpful.

Sure, thanks. I have one of my trademark stomp boxes with pluggable
short and long wave 1.25 Gb/s modules. BTW on those ones you can hack
the coupling caps. A faster one would be very useful.

They are telecom parts; I suspect that the laser doesn't ever go to
extinction. Gotta test that. The ac coupling time constants are all
over the place.

Cheers

Phil Hobbs

Do you want a couple of these?

https://www.dropbox.com/s/yjau853aun1xvb7/Z482_SFP.jpg?raw=1

I hope I got that right!


Sure thing!

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com