Fig. 7
From: Low-power transcutaneous current stimulator for wearable applications
Test voltages of HVCP. The traces demonstrate: (1) how the bootstrapping of OA1’s supply lines allow it to output a range beyond its usual limits, and (2) how inverting the current pump output onto the second electrode allows for the full 60 V to be applied bidirectionally over the electrodes. Test conditions were driving a 2 mA peak to peak sinusoidal current into a 60 k\(\Omega \) load at 500 Hz