IC 3130 REPLACEMENT

[pgr2002]

The above circuit is "Simple Micro Ampere Meter Circuit" convert & help in measuring small currents in five ranges: from 1 µA to 10 mA. . For example if a 1 mA meter is used, the total resistance (the sum of the resistor R and the coil resistance Ri of the meter) must be 1kΩ. If a 100 µA meter is used, the total resistance must be 100 kΩ. If needed, a potentiometer can be used for the R.
Now the problem lies in getting the IC3130. Can we use LM741 or any other Op-Amp IC instead of 3130? Any other ideas regarding this circuit for further modifications.

 

[dick_freebird]

Mouser has them listed in a couple of package
styles. Renesas now holds the bag on all the old
RCA, GE, Harris, Intersil parts. The problem may
be with country / organization of destination,
or one's willingness to fill out paperwork and
wait?

Its claim to fame is MOSFET inputs (high Z) but
I'd say that aspect is no better than many BiFET
op amps. It claims rail-rail output with its CMOS
output stage but the application appears not
to need that. Its input offset is pretty poor
(+/-22mV), a BiFET op amp should come in
under 5mV (and may offer user nulling pins).

If you have an easier time acquiring JFET-input
op amps then I'd set about selecting one based
on what you know re "care-abouts".

 

[KlausST]

Hi,

Honestly I doubt that this can work.
I think it's either complete nonsense, or there's something missing, or I'm to dumb to read it.

Some issues:
* no power supply capacitors
* a Voltmeter in series with an R??
* where do they expect the current (up to 10mA) in the "current IN" node to flow? Through the voltmeter? Through the 10k? -(-> this needs 100V..)

Klaus