Boosting LCD panel meter sensitivity

[JERD]

I have one of those LCD 0-200mV panel meters that I want to boost its
sensitivity to 0-50mV. Absolute accuracy is not important, more of an
'indication'. Any suggestions how to best do this?

JERD

 

[glenbadd]

On Oct 18, 4:37 am, "JERD" <jed...@REMOVEbigpond.net.au> wrote:

I have one of those LCD 0-200mV panel meters that I want to boost its
sensitivity to 0-50mV. Absolute accuracy is not important, more of an
'indication'. Any suggestions how to best do this?

JERD

Add a non-inverting gain 4 pre-amplifier, say using a low power single
opamp chip. Choice of chip depends on power supply alternatives.

HTH,
Glenn.

 

[JERD]

"glenbadd" <glennbaddeley@yahoo.com.au> wrote in message
news:1192669711.729196.61270@v23g2000prn.googlegroups.com...

On Oct 18, 4:37 am, "JERD" <jed...@REMOVEbigpond.net.au> wrote:
I have one of those LCD 0-200mV panel meters that I want to boost its
sensitivity to 0-50mV. Absolute accuracy is not important, more of an
'indication'. Any suggestions how to best do this?

JERD

Add a non-inverting gain 4 pre-amplifier, say using a low power single
opamp chip. Choice of chip depends on power supply alternatives.

HTH,
Glenn.

Hi Glenn and thanks for this info. Power supply is 12v DC. Can you give me a
pointer to suitable IC please? I'll have a friend make it up for me

Ta!
JERD

 

[Phil Allison]

"JERD"

I have one of those LCD 0-200mV panel meters that I want to boost its
sensitivity to 0-50mV. Absolute accuracy is not important, more of an
'indication'. Any suggestions how to best do this?

** It don't make sense to even try.

A 3.5 digit display has 2000 counts so cannot show " 50.00 mV " - it can
only show " 050.0 mV " which it will do as it is right now.



........ Phil

 

[cd954]

The easy way out, near the trimpot there's a resistor R2 ~ 27K -30k that
controls the ref voltage to100mv
for 200mV FS.
Half that resistor by placing another 27K in parralel, to give you 50mv ref
adjust the trimpot if needed.
the result will be 0 to100mv meter.
see ICL7106 data sheet for more info.

Cd954


"JERD" <jedunk@REMOVEbigpond.net.au> wrote in message
news:WsARi.787$CN4.326@news-server.bigpond.net.au...

"glenbadd" <glennbaddeley@yahoo.com.au> wrote in message
news:1192669711.729196.61270@v23g2000prn.googlegroups.com...
On Oct 18, 4:37 am, "JERD" <jed...@REMOVEbigpond.net.au> wrote:
I have one of those LCD 0-200mV panel meters that I want to boost its
sensitivity to 0-50mV. Absolute accuracy is not important, more of an
'indication'. Any suggestions how to best do this?

JERD

Add a non-inverting gain 4 pre-amplifier, say using a low power single
opamp chip. Choice of chip depends on power supply alternatives.

HTH,
Glenn.


Hi Glenn and thanks for this info. Power supply is 12v DC. Can you give me
a pointer to suitable IC please? I'll have a friend make it up for me

Ta!
JERD