
254 Analog Electronics
reckon that the fuse should protect the switch, by
being located on the mains input side. Either way,
the fuse holder should be constructed and con-
nected in such a way that, with the instrument
plugged in and switched on, there is no possibility
of the outer end of a new fuse being inserted into
the holder becoming live. Another important
safety point concerns the fuse rating where the
transformer has more than one secondary wind-
ing, of very different VA ratings. Suppose that, in
Figure 10.9a, the rating of each of the auxiliary
windings is just 5% of the rating of the main
winding. If all the windings have the sam