Multi-Tap Transformer For Voltage Regulation

Multi-tap transformer is one of the main and expensive component of this technique. The cost of multi-tap transformer directly affect the cost of this technique. Depending upon the percentage regulation and precision the number of taps can be increased or decreased. This will also increase the cost and size of regulatory circuit. The size of transformer depends upon the current rating and operating voltage. In our project, we used 500VA, 6 tap transformer. That can bear a maximum voltage of 500V. Different turns ratio of taps is given in table below.

Tap No.	Turns Ratio	Input voltage	Output voltage
1	1	220V	220V
2	1.128	195V	220V
3	1.294	170V	220V
4	1.517	145V	220V
5	1.83	120V	220V
6	0,88	250V	220V

The regulation that can be achieved using this transformer is from 110V to 260V. While the minimum error that can be achieved is ±12.5 volt. Because turns ratio of taps is such that there is difference of 25V to have 220V at the output. By increasing the number of taps precision can be increased but that will result in large cost and size of the regulatory circuit. Multi-tap transformer that we used in this technique is shown in figure.