diff --git a/ohmpi/hardware_components/mb_2023_0_X.py b/ohmpi/hardware_components/mb_2023_0_X.py
index 52a750bfde6f30a804677ed54611963d35fefb6b..66d295e27b727b353682d9d43d659a03cbb36061 100644
--- a/ohmpi/hardware_components/mb_2023_0_X.py
+++ b/ohmpi/hardware_components/mb_2023_0_X.py
@@ -225,7 +225,7 @@ class Tx(TxAbstract):
         self.exec_logger.debug(f'{self.board_name} cannot read battery voltage. Returning default battery voltage.')
         return self.pwr.voltage
 
-    def voltage_pulse(self, voltage=self.voltage, length=None, polarity=1):
+    def voltage_pulse(self, voltage=None, length=None, polarity=1):
         """ Generates a square voltage pulse
 
         Parameters
@@ -241,7 +241,8 @@ class Tx(TxAbstract):
         # self.exec_logger.info(f'injection_duration: {length}')  # TODO: delete me
         if length is None:
             length = self.injection_duration
-        self.pwr.voltage = voltage
+        if voltage is not None:
+            self.pwr.voltage = voltage
         self.exec_logger.debug(f'Voltage pulse of {polarity*self.pwr.voltage:.3f} V for {length:.3f} s')
         self.inject(polarity=polarity, injection_duration=length)
         self.exec_logger.event(f'{self.board_name}\ttx_voltage_pulse\tend\t{datetime.datetime.utcnow()}')
diff --git a/ohmpi/utils.py b/ohmpi/utils.py
index 6f133d04d2ffa8e6451a4a47cfb0f042b5feeb74..142d4fb40fa4627bebaeb5f84e578adb52291cfa 100644
--- a/ohmpi/utils.py
+++ b/ohmpi/utils.py
@@ -5,6 +5,7 @@ import collections.abc
 import numpy as np
 from numbers import Number
 
+
 def enforce_specs(kwargs, specs, key):
 
     kwargs.update({key: kwargs.pop(key, specs[key]['default'])})