hi audioguru, i see the datasheet of the mosfet of IRF540, if the ic CD4047 produces output of 5V the the Vds would be 7.5A from the mosfet. ??? ??? i still cant think of how to supply the 10V to the transformer? is it from the +5 and -5V from the IC??? how do the mosfet do its job??? thanks for your reply :-[