Need for low input impedance

Hi all,

I need to know, why low input impedance is

needed for current input.

Could any one give complete details why its needed ?

Thanks in advance.

Hi,

Could any one give complete details why its needed ?

Click to expand...

First you should give enough information what you are talking about.
Just posting a statement without context is useless, it's just a riddle for us.

--> Give schematic, values, documents, web links ...

Klaus

I want to use some electronic device(Thermsitor) as an oscillator, So, in order to use some device as an oscillator,

do we need low input impedance ?

What are the conditions for a device to be used as an oscillator ?

In which places do we require low input impedance ?

vetriece86@gmail.com said:

I want to use some electronic device(Thermsitor) as an oscillator, So, in order to use some device as an oscillator,

do we need low input impedance ?

What are the conditions for a device to be used as an oscillator ?




In which places do we require low input impedance ?

Click to expand...

Are you trying to control an oscillator with a thermistor? As i temperature to Frequency conversion.

Or, are you trying to make thermistor into an oscillator with some form of thermo feed back?

vetriece86@gmail.com said:

Hi all,

I need to know, why low input impedance is

needed for current input.

Could any one give complete details why its needed ?

Thanks in advance.

Click to expand...

**broken link removed**

Rp is the parallel resistance/impedance of your input current source, Rin in the input resistance/impedance of your circuit, which I've represented as an amplifier as U1 here.

If Rin is low (relative to Rp), most of the current I flows through Rin and thus through the input of your circuit -- which is desired.

If Rin is high (relative to Rp), most of the current I flows through Rp and thus not through the input of your circuit -- this is not desired.