problem with grounds

Hello

I posted a simple circuit up on
http://www3.sympatico.ca/captoro/motor/design1.gif
I am having difficulty seperating the grounds. My final circuit is
much more complex, it may look trivial at first, but I absolutely need
to seperate the grounds. IN the simulator they are the same ground.
But my 30 v source comes from a separate circuit, therefore do not
activate the N-mosfet (no common ground). I need to figure out a way
to put 30v on the mosfet so that the rest of the circuit shown sees it
and operate the way it is showing.
I thought about adding opto couplers, but I will still have the
problem of finding 30v on the other side of the circuit to activate
the mosfets,( where the maximum volt is 24v). And no I cannot combine
the 24v and 12v.
anyone has any ideas?

thank you

K

Posted by Jamie on September 20, 2008, 9:16 pm

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lerameur wrote:

> Hello
>
> I posted a simple circuit up on
> http://www3.sympatico.ca/captoro/motor/design1.gif
> I am having difficulty seperating the grounds. My final circuit is
> much more complex, it may look trivial at first, but I absolutely need
> to seperate the grounds. IN the simulator they are the same ground.
> But my 30 v source comes from a separate circuit, therefore do not
> activate the N-mosfet (no common ground). I need to figure out a way
> to put 30v on the mosfet so that the rest of the circuit shown sees it
> and operate the way it is showing.
> I thought about adding opto couplers, but I will still have the
> problem of finding 30v on the other side of the circuit to activate
> the mosfets,( where the maximum volt is 24v). And no I cannot combine
> the 24v and 12v.
> anyone has any ideas?
>
> thank you
>
> K

Optical isolation.

Look for optocouplers.

Below is a good component and many like it.

http://www.supertex.com/pdf/app_notes/AN-D26.pdf

the application notes should give you some lead way.

http://webpages.charter.net/jamie_5"

Posted by Kris Krieger on September 22, 2008, 2:35 pm

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> lerameur wrote:
>

>> Hello
>>
>> I posted a simple circuit up on
>> http://www3.sympatico.ca/captoro/motor/design1.gif
>> I am having difficulty seperating the grounds. My final circuit is
>> much more complex, it may look trivial at first, but I absolutely need
>> to seperate the grounds. IN the simulator they are the same ground.
>> But my 30 v source comes from a separate circuit, therefore do not
>> activate the N-mosfet (no common ground). I need to figure out a way
>> to put 30v on the mosfet so that the rest of the circuit shown sees it
>> and operate the way it is showing.
>> I thought about adding opto couplers, but I will still have the
>> problem of finding 30v on the other side of the circuit to activate
>> the mosfets,( where the maximum volt is 24v). And no I cannot combine
>> the 24v and 12v.
>> anyone has any ideas?
>>
>> thank you
>>
>> K

> Optical isolation.
>
> Look for optocouplers.
>
> Below is a good component and many like it.
>
> http://www.supertex.com/pdf/app_notes/AN-D26.pdf
>
> the application notes should give you some lead way.
>
> http://webpages.charter.net/jamie_5"
>
>

I'm gettign "file not found" - I also qwent to the site and searched D26, but
that didn't work. Could you post the component name, or another search term
I could use...?

Thanks!

Posted by lerameur on September 22, 2008, 3:11 pm

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Bk.25806$PK.14621@newsfe04.iad:

>
>
>

> > lerameur wrote:

> >> Hello

> >> I posted a simple circuit up on
> >>http://www3.sympatico.ca/captoro/motor/design1.gif
> >> I am having difficulty seperating the grounds. My final circuit is
> >> much more complex, it may look trivial at first, but I absolutely need
> >> to seperate the grounds. IN the simulator they are the same ground.
> >> But my 30 v source comes from a separate circuit, therefore do not
> >> activate the N-mosfet (no common ground). I need to figure out a way
> >> to put 30v on the mosfet so that the rest of the circuit shown sees it
> >> and operate the way it is showing.
> >> I thought about adding opto couplers, but I will still have the
> >> problem of finding 30v on the other side of the circuit to activate
> >> the mosfets,( where the maximum volt is 24v). And no I cannot combine
> >> the 24v and 12v.
> >> anyone has any ideas?

> >> thank you

> >> K

> > Optical isolation.

> > =A0 Look for optocouplers.

> > Below is a good component and many like it.

> >http://www.supertex.com/pdf/app_notes/AN-D26.pdf

> > the application notes should give you some lead way.

> >http://webpages.charter.net/jamie_5"

>
> I'm gettign "file not found" - I also qwent to the site and searched D26,=

but

> that didn't work. =A0Could you post the component name, or another search=

term

> I could use...?
>
> Thanks!

I just tried the 6 links, they all work well:
http://www3.sympatico.ca/captoro/motor/design1.gif
...
http://www3.sympatico.ca/captoro/motor/design6.gif

Anyhow I think I figured it out, I will try it tonight.
I am going to use my circuit as a reference point for the grounding of
my 30v gate voltage. It should work.
k

Posted by Kris Krieger on September 24, 2008, 2:56 pm

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>> > � Look for optocouplers.

>> > Below is a good component and many like it.

>> >http://www.supertex.com/pdf/app_notes/AN-D26.pdf

>> > the application notes should give you some lead way.

>> >http://webpages.charter.net/jamie_5"

>>
>> I'm gettign "file not found" - I also qwent to the site and searched
>> D26,

> but

>> that didn't work. �Could you post the component name, or another search

> term

>> I could use...?
>>
>> Thanks!

>
>
> I just tried the 6 links, they all work well:
> http://www3.sympatico.ca/captoro/motor/design1.gif
> ...
> http://www3.sympatico.ca/captoro/motor/design6.gif
>
>
> Anyhow I think I figured it out, I will try it tonight.
> I am going to use my circuit as a reference point for the grounding of
> my 30v gate voltage. It should work.
> k
>

Hmm, no go her. I viewed the Source and this is it:

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<HTML><HEAD>
<TITLE>404 Not Found</TITLE>
</HEAD><BODY>
<H1>Not Found</H1>

The requested URL /captoro/motor/design6.gif was not found on this

server.<P> <HR>
<ADDRESS>Apache/1.3.36 Server at www3.sympatico.ca Port 80</ADDRESS>
</BODY></HTML>

Well, no biggie, I was just curious to take a look.

- Kris

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Hobby Electronics Basics problem with grounds