Isolating a power souce

[Rheilly Phoull]

G'Day All

I am using some of the chinese DVM's in my vehicle to monitor a solar setup,
(volts and amps). However they cannot be used powered directly from the
vehicle batteries etc.
It occurs to me that mebbe a small double wound transformer used in a
switching mode followed by the usual regulation and smoothing etc could be
used to feed a small 9v recharge battery and as the supply for the meters.
Would that be isolating the supply for the meters or have I missed something
??


--
Regards ......... Rheilly Phoull

 

[David L. Jones]

Rheilly Phoull wrote:

G'Day All

I am using some of the chinese DVM's in my vehicle to monitor a solar setup,
(volts and amps). However they cannot be used powered directly from the
vehicle batteries etc.
It occurs to me that mebbe a small double wound transformer used in a
switching mode followed by the usual regulation and smoothing etc could be
used to feed a small 9v recharge battery and as the supply for the meters.
Would that be isolating the supply for the meters or have I missed something
??

Easier to just buy an isolated DC-DC converter like the C&D/Newport
type.
www.dc-dc.com
Not as cheap as rolling something yourself though I guess.

Dave

 

[Andrew M]

jump onto the TI website and sample yourself some DCP011212 or similar....

-Andrew M
Top poster extraordinaire


"Rheilly Phoull" <Rheilly@bigpong.com> wrote in message
news:43ab718a$0$14640$5a62ac22@per-qv1-newsreader-01.iinet.net.au...

G'Day All

I am using some of the chinese DVM's in my vehicle to monitor a solar setup, (volts
and amps). However they cannot be used powered directly from the vehicle batteries
etc.
It occurs to me that mebbe a small double wound transformer used in a switching mode
followed by the usual regulation and smoothing etc could be used to feed a small 9v
recharge battery and as the supply for the meters.
Would that be isolating the supply for the meters or have I missed something ??


--
Regards ......... Rheilly Phoull

 

[Jasen Betts]

On 2005-12-23, Rheilly Phoull <Rheilly@bigpong.com> wrote:

G'Day All

I am using some of the chinese DVM's in my vehicle to monitor a solar setup,
(volts and amps). However they cannot be used powered directly from the
vehicle batteries etc.
It occurs to me that mebbe a small double wound transformer used in a
switching mode followed by the usual regulation and smoothing etc could be
used to feed a small 9v recharge battery and as the supply for the meters.
Would that be isolating the supply for the meters or have I missed something
??

that'd do it,

I have here an old (ex) NE2000 compatible network card,
on it there is a VALOR PM7202 module.
<http://www.geocities.com/CapeCanaveral/Hangar/5833/datasheets/PM7202.pdf>

This is a 5V to 9V converter with 2KV isolation capable of supplying 200ma.
stick a 7805 on the input and you have an isolated 9V supply...

send SAE (to kiwiland) for "free sample"... otoh there's probably sommeone
near you with a tub full of old network cards....

If you find that the battery negative is connected directly to the negative
probe you could power that meter from the battery (using an apropriate
regulator)

--

Bye.
Jasen