We pay about $4 for VASD1 dual-output converters. They don't even get warm at 1 watt out.
-- 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
Ah, sorry, it was a Freudian lapss. I thought cascade instead of multiplier. Yes, absolutamente, there have to be a cap mulipliers for the analog supplies.
They do but does it matter?
You could use a netbook supply since those are much smaller and you don't need lots of power. Electrolytics are ok if used indoors. You can get 5k/125C versions. But you'd have to ship different wall warts for each market. A laptop brick is easier, all you need is a power cord matching the country's wall outlets. With a wall wart you are stuck and you normally can't use adapters, mainly because then they sag and it's also frowned upon by Inspecteur Clousieau from the fire department.
-- Regards, Joerg http://www.analogconsultants.com/
The product this is intended to replace gets its power from binding posts on the back, marked +15, -15, and ground--the anointed power supply is hundreds of dollars extra. Sort of like a Tektronix probe power supply--$1200 for a +-15V supply and four LEMO connectors. So a $10 modem-style wall wart would be a huge improvement, even if we shipped both US and European ones in every box.
The power supply standard for laptops changes on a shorter time scale than the lifetime of decent electrolytics--last winter I was in San Jose when my 16V Thinkpad power brick died. I found _one_ brick at Fry's (out of several dozen) that had a voltage switch on it. All the others were 18V, and had the wrong connector. With the big shift towards tablets, the laptop power supply doesn't look as timeless as it once did.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
You didn't say what your preferred input voltage is, but you could do all of that easily with a handful of switching regulator chips from just about any of the usual suspects. Switching speeds have gone sky high, which means that inductors are cheap and teeny.
I will admit to advanced laziness, which usually causes me to go with Linear Technology ('cause LTSpice has good models). But National sells 'em (if you don't mind _no_ models), and so do a whole bunch of other folks.
One for +3.6, one for +15, one for -15, one for +75 -- done!
-- My liberal friends think I'm a conservative kook. My conservative friends think I'm a liberal kook. Why am I not happy that they have found common ground? Tim Wescott, Communications, Control, Circuits & Software http://www.wescottdesign.com
bly
ey'll
d lors
he
ut
and
ven less.
me.
.- Hide quoted text -
There's all sorts of things that get smaller as the signal voltage goes up. DC offsets for one.
George H.
less.
You are correct for bipolar circuits (more voltage means more dynamic range). For CMOS ICs, you often get less noise at lower voltages due to thinner oxide producing higher gm for the same size device.
So you make a boost converter for the photodiode bias. But this voltage is right at the front end. I assume a great deal of effort goes into filtering the bias supply lest it feed into the amp. Why choose the Cockcroft-Walton tripler over a simple two cap charge pump?
Notebooks are not going away.
The universal supplies come with a bag of tips. You pick the tip for you notebook. It has the right physical dimension and the tip programs the voltage. Occasionally you have to request the manufacturer send the tip. That makes it kind of useless for emergency use, but if you have a popular notebook (say Dell), the tip is usually in the bag.
There are maybe four brands of that style. Belkin, Kensington, Igo, and APC. I'm sure they are all ODMd.
On a sunny day (Mon, 09 Jul 2012 16:31:19 -0400) it happened Phil Hobbs wrote in :
I would use a small one transistor sine oscillar, feedback from emittor, like J.L. suggested, and I use for my photomultiplier HV. You can regulate that from say a 2V DC wallwart. The 3.6 with a LM2596 or the like. Custom transformer, only a few turns in your case, on a small EI core, or potcore.
(probably
they'll
regulators
and
less.
me.
the
As the wise man said, "What we have here is a failure to communicate."
Try doing a front-end design sometime. The issues will become clearer very rapidly.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
(probably
they'll
and
wall
regulators
the
but
and
even less.
trust me.
Droping the
Sorry to bite your head off like that, miso. As I said in another post, I'm having problems getting paid by a large customer who certainly has enough money. Nothing personal.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
The new universal power input is 5 volts micro-USB. That will be around for about forever. And a 5 or 12 volt wart with a barrel connector is a good long-term bet.
-- 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
probably
-V
x value.
s, and
rmer.
C wall
gulators
of the
ts, but
her, and
it
ply
too
ere for
d SEPIC
his
ng an
M317
obably
.of
at
with
or.
to
ill
a FET
.ve
ough
because
ck
voltage
some
anghai"
Also
eeding
e the
ase.
t af 10
s run
apy
n d sseems to be three more or less standard psus;
5V usb, phone chargers etc. 12V barrel for external hdds ~19V barrel for laptops-Lasse
(probably
value.
and
wall
regulators
the
but
and
SEPIC
FET
because
voltage
Shanghai"
We are buying a "high-end" Samsung USB supply with 3' cable for about $4. The low-end versions cost around $1 but won't reliably start up some loads.
A good switcher will current limit. Cheap ones sometimes detect overcurrent and shut down for a while, then retry. That won't pull up a negative-impedance load, like downstream switchers. We make sure all our internal switchers soft-start and/or have a startup threshold to minimize this risk.
I recently had a MeanWell switcher do this to me. It's seeing about
40,000 uF of capacitive load, and it goes into the repeated shutdown mode at powerup, and takes 15 seconds to come up.-- 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
Bingo! That would be the really future-proof way of doing that. At least in some parts of Europe chargers have already been standardized by law in some areas. If there's enough power it won't be a problem to make all the required voltages from that.
However, if the wall wart has one of those computer accessory brand names on it a high-falutin physics lab won't consider this anointed :-)
[...]-- Regards, Joerg http://www.analogconsultants.com/
(probably
value.
regulators
and
Well, put a sticker over the brand name and multiply the price by 5x or so. Unless you are a major instrument manufacturer, A***** or T********, where you can use 15x.
-- 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
J.L.
potcore.
Spread-spectrum switching is an option for something whose output might be analyzed in the frequency domain. It's usually easy and can drop spectral lines 20 dB or more.
-- 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
(probably
value.
regulators
the
but
and
SEPIC
because
voltage
Shanghai"
Ah, no prices means it's like with Rolls-Royce parts, one does not ask for pricing :-)
-- Regards, Joerg http://www.analogconsultants.com/
I've done this before in 120/240 50/60Hz powered instruments- using multipliers and such like. It's a bit nicer with a center-tapped xfmr because you can use a single HD04 (WO4 in the old days) and a couple of caps to get +/-V full wave rectified (assuming most of the current goes from +15 to -15, the load is reasonably balanced on the transformer and you only have to overrrate for the capacitive loading).The diodes themselves introduce a bit of 120Hz hash when they switch, but you know how to deal with that. Using half-wave rectification just doubles the cap size, not a huge deal most likely. Probably power line isolation is a bit better with an approved linear supply than a switching supply. The caps in the unit will likely fail before anything else.
Last time we needed linear adapters I simply had exactly what I wanted made, all UL and CSA with our own logo on them. We needed some thousands of pieces, not sure how that would work with smaller lots, and you also want to be reasonably sure (even with the approvals) that nothing with your name on it is going to do anything embarassing.
(probably
value.
and
wall
regulators
the
but
and
SEPIC
FET
because
voltage
Shanghai"
Right. Just give us your PO number.
It's like Obamacare: "You have to pass the bill to see what's in it."
-- 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
(probably
value.
regulators
and
Why would anybody choose a micro-usb connector for anything that had room for a bigger connector. They're just too fragile.
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.