0-25mA & 0-100mV Simulator Diagram 24VDC Supply

Late homework?

Thank you for replying! Its a group project, but we need to finish it as soon as possible.

But still homework right? Two questions for you: If we tell you the answer, what have you or the rest of the group learned? And do we get an A+ for doing your work?

Let me give you a hint to get you started: E=I*R

And from your first post: Is the 24VDC supply limited to 750ma?

... and (with only passive components) you'll need to know the load impedance.

@ Kilowatt0 - thanks for replying, My course is Instrumentation and we rarely discuss about electronic components, that's why I'm asking here. I was thinking of using IC like LM7805 or LM317. For the question, yes the 24VDC supply is limited to 750mA only.

@JohnDG - is it not easier to do if I'll use ICs?

Yes.

Okay? Can you give other hints? Some intermediate hints not like Ohm's law. Thanks!

You'll need a multi-pole selector switch to do both the voltage and current sources with just one pot. Two circuits would be much simpler IMHO.

Don't think you'll get the ranges you want using just a regulator, adjustable or not (someone may correct me). Look up some op-amp application notes.

<...0-25mA...> It was 4-20mA a post or two ago. Which one is correct?

So you want to switch between a current source and a voltage source mode of operation. However, you don't know where to search for this information. I was tempted to use LMGTFY but my point is still made.

WARNING: You should still be required to explain/prove why your circuit performs in each mode.

I found you an electronics tutor, my time can't be wasted doing your homework

If you post the circuit that you have been thinking about you might get more responses. Otherwise people with memories of staying up late doing their own homework might not take the time to do your homework for you.

Deadlines have reasons for being imposed.

If you ever venture out into the real world, you may not have the luxury of asking others to do the work.

That's why project planning is so important.

Draw a line on a piece of paper. Put today's date at one end, deadline date at the other. List the major tasks as milestones. Allocate time for each task and get busy solving each one in order.

Or, look for existing schematics to steal copy borrow use.

Thank you! I appreciate you all!

Thank you for all your replies and comments. We first tried the 0-25mA by using LM317 here:

We used this circuit, in the docircuits the output is 4-20mA but when we tried in in actual, the output is only playing along 13mA.

And then we tried LM7805, but I don't have the soft copy of our diagram. But the output in actual is lying from 3mA to 10mA.

BTW, we'll be using selector switch for the switching of our modes(mA or mV).

Please help or suggest for the circuit of mA. Thank you!

CR4 compresses picture files so much that engineering documents are unreadable. I cannot read your component values so I cannot comment too much about the circuit. [I'm not sure why you have a pair of LED on the left hand side unless you intend this to be a wiring polarity check.] Post your schematic to a share site and post the link to it here. It would also be good to identify where (if anywhere) did you copy this design from and most importantly a brief description of your analysis of how this circuit works.