how to design the interface circuit

[electronic_satya]

Hi all,

I will briefly explain my setup and shown as an attachment

1. The hardware board 1 on its output pin gives 24V and depending on the resistance value it gives out X amps current.

2. I have another hardware board-2 which is capable of reading up to 24V but the current capability is limited to some 100mAmps.

3. Now my requirement is to interface the hardware board -1 and hardware board -2 through some interface board so that only 24v appears on the input of Hardware board -1 and very little current comes in.

could somebody suggest me the design of the interface board i hope some opamp circuit will work?


Thanks in advance,
Regards,
satya

 

[chuckey]

I do not understand your problem. You have a resistor with +24V across it (from hardware board 1) and you want to feed the 24V to another board - whats wrong with a piece of wire, the current hardware board 2 depends on its input impedance. If the input impedance is too low (so diverting too much current), then you need a buffer amp that reduces the current and increases its input impedance.
Frank

 

[electronic_satya]

Hi Frank,

Thank you for the reply. Yes exactly I need a buffer amp circuit, could you please suggest me some circuits I never designed any hardware circuit.

Thanks and regards,
Satya

 

[nikhildascl]

You refer this for Buffer amp....
www.analogzone.com/col_01302004.pdf

 

[electronic_satya]

Hi,
Thank you for the reference circuit. But i have a single 24V supply from which i have to acheive the buffer circuit, is it possible to do it? The design in link requires a -5V source.

Thanks and regards,
satya

 

[nikhildascl]

You can simply make -5V using 7805 3 terminal voltage regulator IC. Hope you are familiar with that. You can refer 78xx series datasheet here.