Fig. 2
From: Low-power transcutaneous current stimulator for wearable applications
Design of a 9–72 V converter using cascaded voltage inverters. The positive terminal of the input supply becomes the high voltage output, and the most negative output of the inverters, − 63 V, is 72 V below the positive terminal and forms the negative output of the high voltage supply. The blocks A, B, C and D are each independent voltage inverters capable of inverting a maximum of 18 V