## Sunday, 14 October 2012

### Impedance matching–What does a mountain bicycle has in common with a transformer

As a cyclist and a transformer user, can’t help to notice the similarity of the two. So below is the picture of a mountain-bicycle and transformer taken from my favourite source Wikipedia.

To compare them, look at the table of comparison below:
 A Bicycle A Transformer number of “teeth” of sprocket number of winding front sprocket primary winding rear sprocket secondary winding gear chain transformer core
now, isn’t this amazing?

To understand sprocket, visit http://en.wikipedia.org/wiki/Sprocket

Pictures from :

http://en.wikipedia.org/wiki/Bicycle

http://en.wikipedia.org/wiki/Transformer

## Friday, 5 October 2012

### Getting to know simulation - Part11 - Monte Carlo

To best illustrate the usefulness of the monte-carlo simulation, let’s use a voltage divider as example.
Run Transient simulation and get:
So this is a perfect voltage divider. But we all knows that resistor has tolerance, let’s say each of R1, R2 has 1% tolerance. We should factor this in by running Monte Carlo simulation and see what are we dealing with.
Enter 1% as the resistor tolerance.
Tick “Enable multi-step” to enable Monte-Carlo analysis

Set number of runs to 100
Re-run the transient simulation to see gain statistic of  divider made of 2 pieces of 1% resistor.
With resistor tolerance of 1%, the voltage divider will give an error of ~-0.9% to ~+1%. Use of Monte-Carlo simulation will ease such analysis. If your application cannot tolerate such variance, then resistors with better tolerance are needed.