ac constatnt current source

Thread Starter


Joined Jun 9, 2006
I want to make constant ac current source ciurcuit. The frequency range is from 100 Hz to 10 kHz (approx.). The reference for the ac signal will be provided by a low power oscillator.

The maximum current needed is about 20 mA and the output power is 25 mW.

The basic requirements are:

1. The circuit should provide ac current to the load, and the frequency of the ac current should be same as the input reference ac voltage.

2. The output current should not vary with the small variation (say 10%) of the load impedence.

It will be nice, if anybody can help me by providing circuit for such a current source.

Ron H

Joined Apr 14, 2005
Is the load grounded, or can it be floating? What is the application? Sounds like you might be measuring headphone impedance.
There are several ways to do this, and which one you choose depends on the application.