stonehenge regulator

J

John Larkin

Guest
I have a 48 volt power supply and I want to drive a lot of relays and
uPs and FPGAs and stuff, so I figured I'd knock it down to 12 volts
first.

We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher probably
designed by druids during the last ice age. Figured I'd breadboard the
reg just for fun. A boy gets tired of typing all day.

https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchljjrxka4aHZItfa?dl=0


Works pretty well, actually. Nothing gets very warm at 1 amp out.

Yes, that unshielded drum core will spray field everywhere, but then I
am simulating alternators.
 
On 9/26/19 5:56 PM, John Larkin wrote:
I have a 48 volt power supply and I want to drive a lot of relays and
uPs and FPGAs and stuff, so I figured I'd knock it down to 12 volts
first.

We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher probably
designed by druids during the last ice age. Figured I'd breadboard the
reg just for fun. A boy gets tired of typing all day.

https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchljjrxka4aHZItfa?dl=0


Works pretty well, actually. Nothing gets very warm at 1 amp out.

Yes, that unshielded drum core will spray field everywhere, but then I
am simulating alternators.
Click to expand...

Stonehenge! Where the demons dwell
Where the banshees live and they do live well
Stonehenge! Where a man's a man
And the children dance to the Pipes of Pan
 
On Thu, 26 Sep 2019 15:11:14 -0700 (PDT), tabbypurr@gmail.com wrote:

On Thursday, 26 September 2019 22:56:15 UTC+1, John Larkin wrote:
I have a 48 volt power supply and I want to drive a lot of relays and
uPs and FPGAs and stuff, so I figured I'd knock it down to 12 volts
first.

We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher probably
designed by druids during the last ice age. Figured I'd breadboard the
reg just for fun. A boy gets tired of typing all day.

https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchljjrxka4aHZItfa?dl=0


Works pretty well, actually. Nothing gets very warm at 1 amp out.

Yes, that unshielded drum core will spray field everywhere, but then I
am simulating alternators.

Stone age would be a carbon pile adjusted by a solenoid.


NT
Click to expand...

Dynamotor.
 
On Thursday, 26 September 2019 22:56:15 UTC+1, John Larkin wrote:
I have a 48 volt power supply and I want to drive a lot of relays and
uPs and FPGAs and stuff, so I figured I'd knock it down to 12 volts
first.

We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher probably
designed by druids during the last ice age. Figured I'd breadboard the
reg just for fun. A boy gets tired of typing all day.

https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchljjrxka4aHZItfa?dl=0


Works pretty well, actually. Nothing gets very warm at 1 amp out.

Yes, that unshielded drum core will spray field everywhere, but then I
am simulating alternators.
Click to expand...

Stone age would be a carbon pile adjusted by a solenoid.


NT
 
Am 27.09.19 um 00:27 schrieb bitrex:

Stonehenge! Where the demons dwell
Where the banshees live and they do live well
Stonehenge! Where a man's a man
And the children dance to the Pipes of Pan
Click to expand...

No more banshees and demons.
Nowadays: tourists, by the 1000s.


The parking lot is 5 Km away, and an endless stream
of people between the parking lot and the stones.

We gave up. The picture is a drive-by shot from the
country road, from the moving motorbike. Wide angle lens,
obviously without looking through the camera and later
cropped/rotated in the computer.

And we got wet!
Riding a submarine would have been appropriate for that trip.

<
https://www.flickr.com/photos/137684711@N07/27945899204/in/album-72157668637947473/
>

Orkney is much better, if you can go there.
<
https://www.flickr.com/photos/137684711@N07/22892154751/in/album-72157660575819870/
>

Gerhard
 
John Larkin wrote...
I have a 48 volt power supply and I want to drive a lot of
relays and uPs and FPGAs and stuff, so I figured I'd knock
it down to 12 volts first.

We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher
probably designed by druids during the last ice age.
Figured I'd breadboard the reg just for fun. A boy gets
tired of typing all day.

https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchljjrxka4aHZItfa?dl=0

Works pretty well, actually. Nothing gets very warm at 1 amp out.
Click to expand...

LM2576? Too bad you have the slow-mo 52kHz versions in stock.
Would be better if you had the 150kHz LM2596 in stock instead.
Time to over-rule the established inventory tyranny.


--
Thanks,
- Win
 
Gerhard Hoffmann wrote...
The parking lot is 5 Km away, and an endless stream
of people between the parking lot and the stones.
Click to expand...

I rode by on the train to Bath, imagining the scene,
without any tourist distractions.


--
Thanks,
- Win
 
On Friday, September 27, 2019 at 9:38:49 AM UTC+10, Gerhard Hoffmann wrote:
Am 27.09.19 um 00:27 schrieb bitrex:

Stonehenge! Where the demons dwell
Where the banshees live and they do live well
Stonehenge! Where a man's a man
And the children dance to the Pipes of Pan

No more banshees and demons.
Nowadays: tourists, by the 1000s.

The parking lot is 5 Km away, and an endless stream
of people between the parking lot and the stones.

We gave up. The picture is a drive-by shot from the
country road, from the moving motorbike. Wide angle lens,
obviously without looking through the camera and later
cropped/rotated in the computer.

And we got wet!
Riding a submarine would have been appropriate for that trip.
Click to expand...

I visited it in the 1970's when you could still wander between the actual stones and actually touch them. Sort of impressive, as it was clearly designed to be.

The astronomical alignments are well documented, but smaller chunks of rock would have done that job equally well.

--
Bill Sloman, Sydney
 
On 26 Sep 2019 18:19:39 -0700, Winfield Hill <winfieldhill@yahoo.com>
wrote:

John Larkin wrote...

I have a 48 volt power supply and I want to drive a lot of
relays and uPs and FPGAs and stuff, so I figured I'd knock
it down to 12 volts first.

We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher
probably designed by druids during the last ice age.
Figured I'd breadboard the reg just for fun. A boy gets
tired of typing all day.

https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchljjrxka4aHZItfa?dl=0

Works pretty well, actually. Nothing gets very warm at 1 amp out.

LM2576? Too bad you have the slow-mo 52kHz versions in stock.
Would be better if you had the 150kHz LM2596 in stock instead.
Time to over-rule the established inventory tyranny.
Click to expand...

To put a new part into stock, I have to fill out forms and stuff. We
already have 40 different switcher chips in stock. And 75 linear regs.
That should be plenty.

The LM2596 is only rated for 40 volts input. The 2576HV is ok to 60.
There aren't a lot of high voltage switchers around.

Hey, we do have the 2596ADJ in stock!
--

John Larkin Highland Technology, Inc

lunatic fringe electronics
 
On 27/09/19 00:38, Gerhard Hoffmann wrote:
Am 27.09.19 um 00:27 schrieb bitrex:

Stonehenge! Where the demons dwell
Where the banshees live and they do live well
Stonehenge! Where a man's a man
And the children dance to the Pipes of Pan

No more banshees and demons.
Nowadays: tourists, by the 1000s.


The parking lot is 5 Km away, and an endless stream
of people between the parking lot and the stones.

We gave up. The picture is a drive-by shot from the
country road, from the moving motorbike. Wide angle lens,
obviously without looking through the camera and later
cropped/rotated in the computer.

And we got wet!
Riding a submarine would have been appropriate for that trip.


https://www.flickr.com/photos/137684711@N07/27945899204/in/album-72157668637947473/
 

Orkney is much better, if you can go there.

https://www.flickr.com/photos/137684711@N07/22892154751/in/album-72157660575819870/
Click to expand...

Basically, I agree with that assessment of Stonehenge.
I used to enjoy sitting on the stones and having a picnic,
just as I used to enjoy using Downing St as a shortcut.
No more, alas.

However, there are other nearby places that retain the
atmosphere:
- Avebury ring (largest)
- Silbury hill (can't climb it anymore)
- West Kennet long barrow
and further away:
- Stanton Drew stone circles (second largest)
- Hetty Pegler's tump (like the West Kennet long barrow)
- Kilmartin Glen, in Scotland
 
On 27/09/2019 00:38, Gerhard Hoffmann wrote:

<snip>
No more banshees and demons.
Nowadays: tourists, by the 1000s.


The parking lot is 5 Km away, and an endless stream
of people between the parking lot and the stones.

We gave up. The picture is a drive-by shot from the
country road, from the moving motorbike. Wide angle lens,
obviously without looking through the camera and later
cropped/rotated in the computer.

And we got wet!
Riding a submarine would have been appropriate for that trip.

Gerhard
Click to expand...

The origins of this one are much better documented...
https://en.wikipedia.org/wiki/Achill-henge

Cheers
--
Clive
 
Am 27.09.19 um 10:21 schrieb Clive Arthur:

The origins of this one are much better documented...
https://en.wikipedia.org/wiki/Achill-henge
Click to expand...

Constructed over a weekend?
They should be hired to finish the new Berlin airport!

I have also seen this one on Iceland, still under construction:

<
https://www.flickr.com/photos/137684711@N07/36430535453/in/album-72157688304045365/
>

/Gerhard
 
At the lab we have several of these:

<https://despair.com/products/revelation>

Cheers

Phil Hobbs
 
On Thursday, September 26, 2019 at 5:56:15 PM UTC-4, John Larkin wrote:
> I have a 48 volt power supply and I want to drive a lot of relays...

And what's wrong with old tech? :)

I just approved two designs with the LM2575HVT, another "simple switcher" part.
If you want reduce the chances of over-voltage, you can stick a 56-ohm resistor on the input, without too many hurdles to overcome. That does waste some power, though.

Do they make the 2567 in a fixed 12-volt version, so you can remove those programming resistors? I see in the photo that you're using the adjustable version. Also, do you the really need the 12-volt zener? Is that for kickback on the line or what?
 
On Fri, 27 Sep 2019 04:33:40 -0700 (PDT), mpm <mpmillard@aol.com>
wrote:

On Thursday, September 26, 2019 at 5:56:15 PM UTC-4, John Larkin wrote:
I have a 48 volt power supply and I want to drive a lot of relays...

And what's wrong with old tech? :)
Click to expand...

Looks like nothing! Efficiency is mediocre, but I'll have a 600 watt
power supply, and nothing is getting very hot. The inductor is
stressed and is the warmest part. At that frequency, it should be more
like 500 uH instead of 100, but a 500 uH 1+ amp inductor would be a
monster. I have that 100 uH in stock.

The 1-volt ON drop of the switch isn't a big deal when the supply is
48.

I just approved two designs with the LM2575HVT, another "simple switcher" part.
If you want reduce the chances of over-voltage, you can stick a 56-ohm resistor on the input, without too many hurdles to overcome. That does waste some power, though.

Do they make the 2567 in a fixed 12-volt version, so you can remove those programming resistors? I see in the photo that you're using the adjustable version. Also, do you the really need the 12-volt zener? Is that for kickback on the line or what?
Click to expand...

Two resistors are a small price to pay against stocking a zillion
different fixed-voltage parts.

I probably don't need the TVS at the output. I was thinking about a
startup overshoot, but that actually wouldn't matter in my
application... it wouldn't harm anything. The 48V supply will probably
come up slow anyhow. I have one coming in from Amazon, to test.

This is astounding:

https://www.amazon.com/gp/product/B00G8UDEQ8/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Free Prime 2-day shipping. 13 cents per watt.



--

John Larkin Highland Technology, Inc

lunatic fringe electronics
 
On Thursday, September 26, 2019 at 5:56:15 PM UTC-4, John Larkin wrote:
I have a 48 volt power supply and I want to drive a lot of relays and
uPs and FPGAs and stuff, so I figured I'd knock it down to 12 volts
first.

We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher probably
designed by druids during the last ice age. Figured I'd breadboard the
reg just for fun. A boy gets tired of typing all day.

https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchljjrxka4aHZItfa?dl=0


Works pretty well, actually. Nothing gets very warm at 1 amp out.

Yes, that unshielded drum core will spray field everywhere, but then I
am simulating alternators.
Click to expand...

Isn't that 12V TVS cutting things close?
 
On Fri, 27 Sep 2019 13:47:45 -0700 (PDT),
bloggs.fredbloggs.fred@gmail.com wrote:

On Thursday, September 26, 2019 at 5:56:15 PM UTC-4, John Larkin wrote:
I have a 48 volt power supply and I want to drive a lot of relays and
uPs and FPGAs and stuff, so I figured I'd knock it down to 12 volts
first.

We have LM2567HV-ADJ in stock, a 52 KHz Simple Switcher probably
designed by druids during the last ice age. Figured I'd breadboard the
reg just for fun. A boy gets tired of typing all day.

https://www.dropbox.com/sh/ajtqs7c1nswfhey/AABi7r0gchljjrxka4aHZItfa?dl=0


Works pretty well, actually. Nothing gets very warm at 1 amp out.

Yes, that unshielded drum core will spray field everywhere, but then I
am simulating alternators.

Isn't that 12V TVS cutting things close?
Click to expand...

A 12 volt TVS doesn't conduct at 12 volts. More like 14.

If the reg fails, it would push 48 volts into 7 PC boards that are all
expecting 12. I could include the TVS and maybe an 0805 series
resistor as sacrifial parts, to localize the flames.
 
On Friday, September 27, 2019 at 10:07:29 AM UTC-4, jla...@highlandsniptechnology.com wrote:

This is astounding:

https://www.amazon.com/gp/product/B00G8UDEQ8/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

Free Prime 2-day shipping. 13 cents per watt.
Click to expand...

You can trim Amazon urls at the "/ref="

This goes to the same link:

https://www.amazon.com/gp/product/B00G8UDEQ8
 
On Friday, September 27, 2019 at 10:07:29 AM UTC-4, jla...@highlandsniptechnology.com wrote:
On Fri, 27 Sep 2019 04:33:40 -0700 (PDT), mpm > wrote:
The 48V supply will probably
come up slow anyhow. I have one coming in from Amazon, to test.
Click to expand...

The last MeanWell 48 Volt supply we used in a project took 3 seconds to produce an output. It did not over-shoot.
 
John Larkin wrote...
On 27 Sep 2019, bloggs.fredbloggs.fred@gmail.com wrote:
On September 26, 2019, John Larkin wrote:

I have a 48 volt power supply and I want to drive a
lot of relays and uPs and FPGAs and stuff, so I
figured I'd knock it down to 12 volts first.

Isn't that 12V TVS cutting things close?

A 12 volt TVS doesn't conduct at 12 volts. More like 14.

If the reg fails, it would push 48 volts into 7 PC boards
that are all expecting 12. I could include the TVS and
maybe an 0805 series resistor as sacrifial parts, to
localize the flames.
Click to expand...

To protect those parts, use an SCR shutdown with a fuse.


--
Thanks,
- Win
 
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