Hello everyone,

This is the first time on these forums and I am a beginner when it comes to electronics and PCB design. I have a situation where I need to create a circuit that has a 0-10V signal voltage and create a variable output current up to 5 Arms (sin wave) on a PCB.The impedance on the output load is 0.5 Ohm. I have been trying for a while now in Multisim with parallel mosfets or darlington pair bjts, to get the required output current, filtering it with a butterworth filter, getting it back in phase with an all-pass filter, and have a feedback to an input comparator.

My question is if there is any of you who have experience with these kind of current amplifications with the given input voltage and if you have any suggestions that can possibly send me in the good direction. I would appreciate it a lot since I have been stuck on this for quite a while.

regards

 

What is the frequency of sine and what is the power supply V ?

Regards, Dana.

 

Welcome to AAC!
What AC frequency?
What will provide the power for this current source?
Does it have a voltage limit?
What impedance load do you envisage?
At what rate does the signal vary?
What is the allowable error on proportionality between the input signal and the output RMS current value?
How much latency can you tolerate in determining RMS values?

 

What is the frequency of sine and what is the power supply V ?

Regards, Dana.

The frequency is 50Hz, my first choice was 12 V DC. However, I can do more if it is required.

 

Welcome to AAC!
What AC frequency?
What will provide the power for this current source?
Does it have a voltage limit?
What impedance load do you envisage?
At what rate does the signal vary?
What is the allowable error on proportionality between the input signal and the output RMS current value?
How much latency can you tolerate in determining RMS values?

- 50 Hz,
- 12 V DC power supply
- No limit, can be changed higher or lower
- Resistance load
- I haven't looked into the signal rate yet, I'll have to look into that
- Since this circuit is mainly for simulation purposes it preferably is as close as possible.
- I have not looked into the latency part as well, I'll have to look into that as well.

If these are all required, I'll go do some research on that before coming back here.

and thanks, I hope to stop by more here in the future

 

Maybe adding the circuit I was messing about with to the post will help

 

Obviously in your sim an LM2901 cannot drive more than a few mA into a
load. Essentially you have the comparator output shorted to ground with the
.5 ohm load.

Parts here that go to 10A - http://www.ti.com/amplifier-circuit/op-amps/power/products.html#p233typ=5000;10000

Ref material -

https://www.apexanalog.com/resource...t-in-High-Voltage-POA-with-Current-Buffer.pdf

http://www.ka-electronics.com/images/pdf/Op_Amp_Booster_Stages_pt1.pdf


Regards, Dana.

 

Obviously in your sim an LM2901 cannot drive more than a few mA into a
load. Essentially you have the comparator output shorted to ground with the
.5 ohm load.

Parts here that go to 10A - http://www.ti.com/amplifier-circuit/op-amps/power/products.html#p233typ=5000;10000

Ref material -

https://www.apexanalog.com/resource...t-in-High-Voltage-POA-with-Current-Buffer.pdf

http://www.ka-electronics.com/images/pdf/Op_Amp_Booster_Stages_pt1.pdf


Regards, Dana.

Thanks Dana, I am going to apply this and see what happens