- on Hobby & Modelling
- Published in issue 7/2002 on page 0
An electrically isolated variable transformer is actually an obligatory piece of equipment in every electronics lab. However, many people are put off by the high price of such a device. In a hobby lab, a professional variable transformer is usually grossly overdimensioned, so it’s possible to save a lot of money with a little bit of handiwork. All that you need is a transformer kit for the desired power level and a bit of electronics (Figure 1). This approach can be used to construct a binary-controlled transformer for ac voltages in the 1 to 255-V range with 1-V steps.