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Galvanic isolation without transformers ??

Started by Unknown November 27, 2014
Could some electronics guru please help ?
Maybe this is a very silly question, so 
please pardon me.
A voltage transformer is used to provide 
galvanic isolation, in a power supply, 
amongst other features. Is there another
way to achieve galvanic isolation ? Thanks
in advance.
On Wednesday, November 26, 2014 9:22:06 PM UTC-8, daku...@gmail.com wrote:
> Could some electronics guru please help ? > Maybe this is a very silly question, so=20 > please pardon me. > A voltage transformer is used to provide=20 > galvanic isolation, in a power supply,=20 > amongst other features. Is there another > way to achieve galvanic isolation ? Thanks > in advance.
Don't know if I could be called a guru, but consider what "galvanic isola= tion" means. It means there's no direct current path between two points. There aren't a lot of *feasible* ways to do this that don't involve a tra= nsformer, especially if power transference is the goal. You could go with a= Great Big LED on the supply side and a Sufficiently Efficient PV cell on t= he load side, but that makes feedback difficult. You could go the motor-gen= erator (AKA dynamotor) route, or use a big speaker-dynamic microphone combo= . The common thing is to convert electric power (embodied as current flow) = to some intermediate form (light, torque, sound, etc.) that can be reconver= ted. Transformers convert AC current to changing magnetic fields and back, = and transformers are literally the most efficient machines ever devised. Wh= en transferring power, efficiency matters a lot, which is why you don't oft= en see speakers and mikes (and the other examples I mentioned) in power sup= ply component catalogs. Motor-generators can approach transformers in efficiency in certain circu= mstances but are primarily used to convert DC to AC or to do phase/frequenc= y conversion, harmonic rejection, and other tricks rather than specifically= just provide isolation. Do you have a good reason not to want to use a transformer, or were you j= ust curious? Mark L. Fergerson
daku...@gmail.com wrote:
> > Could some electronics guru please help ? > Maybe this is a very silly question, so > please pardon me. > A voltage transformer is used to provide > galvanic isolation, in a power supply, > amongst other features. Is there another > way to achieve galvanic isolation ?
** I guess you could say 93 million miles of space provides us with galvanic isolation from the sun - though allowing plenty of EM radiation to arrive and do good things. A electric motor /generator set isolates the original AC or DC supply from the output too. One could use air pressure too, by bolting two speakers face to face. .... Phil
On 11/27/2014 12:21 AM, dakupoto@gmail.com wrote:
> Could some electronics guru please help ? > Maybe this is a very silly question, so > please pardon me. > A voltage transformer is used to provide > galvanic isolation, in a power supply, > amongst other features. Is there another > way to achieve galvanic isolation ? Thanks > in advance.
When your purpose is to convey a signal of some type, it is not uncommon to use capacitors to block DC and low frequency signals while chopping the signal of interest to turn it into a higher frequency signal which will pass through the capacitors easily. This will require circuitry on both sides of the interface and so is not as simple as a transformer. But transformers can be bulky, heavy and cost more than a capacitor based approach. Capacitive isolation is usually accomplished by using a pair of chips designed for this purpose, sometimes both on a module in a single package. -- Rick
dakupoto@gmail.com wrote:
> Could some electronics guru please help ? > Maybe this is a very silly question, so > please pardon me. > A voltage transformer is used to provide > galvanic isolation, in a power supply, > amongst other features. Is there another > way to achieve galvanic isolation ? Thanks > in advance.
Well, or AC,one might use a capacitor..and if a DC level needs to be "restored", then modulation may be useful..
The Prickman troll wrote:


> When your purpose is to convey a signal of some type,
** The OP's Q was about power supplies.
> it is not uncommon to use capacitors to block DC and low frequency signals > while chopping > the signal of interest to turn it into a higher frequency signal which > will pass through the capacitors easily.
** The rain in Spain falls mainly on the plain... You fucking tenth wit.
>Capacitive isolation is
** Not the topic. Piss off you vile, Google monkey troll. .... Phil
In article <71bb8bf7-c263-4add-8e10-c668a7603645@googlegroups.com>, 
dakupoto@gmail.com says...
> > Could some electronics guru please help ? > Maybe this is a very silly question, so > please pardon me. > A voltage transformer is used to provide > galvanic isolation, in a power supply, > amongst other features. Is there another > way to achieve galvanic isolation ? Thanks > in advance.
Photo coupling? Jamie
On 11/26/2014 11:21 PM, dakupoto@gmail.com wrote:
> Could some electronics guru please help ? > Maybe this is a very silly question, so > please pardon me. > A voltage transformer is used to provide > galvanic isolation, in a power supply, > amongst other features. Is there another > way to achieve galvanic isolation ? Thanks > in advance. >
Is this for power transfer or just for sensing?
On 11/27/2014 01:52 AM, Phil Allison wrote:
> daku...@gmail.com wrote: >> >> Could some electronics guru please help ? Maybe this is a very >> silly question, so please pardon me. A voltage transformer is used >> to provide galvanic isolation, in a power supply, amongst other >> features. Is there another way to achieve galvanic isolation ? > > > ** I guess you could say 93 million miles of space provides us with > galvanic isolation from the sun - though allowing plenty of EM > radiation to arrive and do good things.
Actually both the Sun and the Earth are immersed in a conducting medium (the solar wind) so their relative potential is very nearly zero. (Feynman has a lecture on that.) The atmosphere is usually a pretty decent insulator, of course, but it's the last few miles that do the isolating, not the first 93 million. 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 hobbs at electrooptical dot net http://electrooptical.net
On Wed, 26 Nov 2014 21:21:58 -0800, dakupoto wrote:

> Could some electronics guru please help ? Maybe this is a very silly > question, so please pardon me. > A voltage transformer is used to provide galvanic isolation, in a power > supply, amongst other features. Is there another way to achieve galvanic > isolation ? Thanks in advance.
Galvanic isolation in what? If you just want to achieve galvanic isolation between two parts, then don't let them touch. If you want to transmit signals from one to the other while maintaining galvanic isolation, that's a different problem. If you want to conduct energy from one point to another while maintaining galvanic isolation, that's yet another problem. So, tell us what your question is, and maybe you'll get a sensible answer or two. -- www.wescottdesign.com