500W Intelligent UP/DOWN Transformer Modifications, What's Inside These

The latest addition to the attic shop. This intelligent step up / down transformer automatically senses the input voltage and selects the proper transformer tap. This allows me to switch between 110V inverter and 220V inverter without worry of damage. Lots of space inside because this is the same case as the 5,000W version. I sometimes need different voltages and have added a switch to insure the input power stays on the 220V transformer tap. I also added MOV and RC network to absorb noise. 500W is all I need for most electronic tests.