hi,If you need full isolation, you need transformer or opto isolation.
Opto isolators are very non-linear. To use them, you either need to convert to digital or you need to use a dual opto isolator. In those, there are two outputs which are as close in characteristics as possible to each other. An op amp is used to make sure that the output current is what is expected, and the other output should be the same.
If there is a limit to the range of the voltage difference between the devices, you could use a differential amplifier.
what i had done is that i had converted input voltage of a single device to pwm pulses and passed through an opto(mct2e) after that i had averaged the signal by a filter but the problem is the output is not linear, also my input is variable from 12v to 40v. i want as the voltage changes the output should also vary and the measurement should be precise.
There is this linear opto. HCNR200
I have used reed switches in scanners, simple to to drive and suitable for analog or digital signals.
This is circuit drawn for an OP, it worked fine.
actually i need a cheaper solution than this, it will be a costly enterprise for me
will you plz tell me how to sense voltage using a reed switch and also keeping isolation in mind
In the way I described, they are isolated or do you mean measure all 50 at the same instant.??hi,
actually i want to measure the voltages and they all should be isolated from each other, also there are 50+ devices so i think think this will not work
Doing this I don't know of an inexpensive way to go about it beyond some of Eric's suggestions. I generally would run with several A to D modules in a 16 bit range (unless you want less accuracy) from a company like NI (National Instruments). Cards or devices like these. The rest depends on what you are writing for software and how it communicates with the choice of data acquisition. When you start looking at 32 channels of A to D with isolated and differential channel inputs and you want 16 bit A/D it can get pricey.actually these devices are dc-dc converters of various ranges, and i am designing a transducer circuit to measure there voltages for a data acquisition system. in that case plz give any fruit ful suggestion
hi,actually these devices are dc-dc converters of various ranges, and i am designing a transducer circuit to measure there voltages for a data acquisition system. in that case plz give any fruit ful suggestion
OK,surely sir it will do. just a rough schematic of ur idea will b enough. thanks 4 taking interest in my question