diff --git a/ohmpi/hardware_system.py b/ohmpi/hardware_system.py
index ba893a8aff0450b93610772d74218af915d822a5..603dce2896619a287e681f6c37b5cb931440d7a7 100644
--- a/ohmpi/hardware_system.py
+++ b/ohmpi/hardware_system.py
@@ -435,7 +435,8 @@ class OhmPiHardware:
             current, voltage = 0., 0.
             diff_vab = np.inf
             if strategy == 'constant':
-                vab_max = tx_volt * 1.001
+                vab_max = tx_volt
+                tx_volt = tx_volt * .9
                 strategy = 'vmax'
             if strategy == 'vmax':
                 while (k < n_steps) and (diff_vab > diff_vab_lim) and (vab_list[k] < vab_max):