Refer to the enclosed image.
1. Draw 3 parallel lines. Set thickness as desired. Select all three and drag it to the Brushes palette and create an Art Brush from it. Accept default options for the brush.
2. Just for illustration, now when you draw a circle, select it, and apply the created brush, you get this.
3. Now back to the project. Draw a small circle and a big one. (Due to lack of space, I’m going to illustrate this using smaller circles.)
4. Select both circles and blend (Object > Blend > Make). Still selected, bring up the Blend Options dialog (Options > Blend > Blend Options…), set Spacing option to Specified Steps, and type in the desired steps value. Don’t make it too tight.
5. Now select the blended circles and just apply the created brush to it. Adjust spacing and such as necessary.
6. Copy/paste the result and position them as you like. Depending on how big you make the circles in step #3, the result will look like the one you specified.
