An actuator circuit comprising: an actuator; a full wave rectifier (15, 57) having a supply ground input and a supply voltage input and a device ground output and a device voltage output; wherein the full wave rectifier (15, 57) has first and second terminals for connection to the supply voltage input and a first ground, respectively, and having third and fourth terminals for supplying the device voltage output and a second ground, respectively; wherein the first ground is the supply ground input and the second ground is the device ground output; and wherein the first terminal of the rectifier is connected to an anode of a first diode and to a cathode of a second diode; the second terminal of the rectifier is connected to an anode of a third diode and to a cathode of a fourth diode; the third terminal is connected to the cathode of the first diode and to the cathode of the third diode; and the fourth terminal is connected to an anode of the second diode and to an anode of the fourth diode; a DC modulating control signal (23, 54) source output configured to provide a modulating voltage for controlling the actuator; a differential amplifier (26, 77) having a first input for receiving a first voltage measurable between the supply ground input and the device ground output, and a second input for receiving a second voltage measurable between the DC modulating control signal source output and the device ground output; and a linearization circuit comprising a transistor having an input connected to an output (38, 78) of the differential amplifier (26, 77) and having an output that can go to zero, wherein the output (38, 78) of the linearization circuit is configured to provide a signal down to zero for controlling the actuator; wherein the transistor comprises a field effect transistor having a gate connected to the output (38, 78) of the differential amplifier, a source connected to the second ground, and a drain connected to the output of the linearization circuit; and wherein the DC modulating control signal (23, 54) source output is connected across the second input of the differential amplifier (26, 77) and the supply ground input of the full wave rectifier (15, 57). an actuator; a full wave rectifier (15, 57) having a supply ground input and a supply voltage input and a device ground output and a device voltage output; wherein the full wave rectifier (15, 57) has first and second terminals for connection to the supply voltage input and a first ground, respectively, and having third and fourth terminals for supplying the device voltage output and a second ground, respectively; wherein the first ground is the supply ground input and the second ground is the device ground output; and wherein the first terminal of the rectifier is connected to an anode of a first diode and to a cathode of a second diode; the second terminal of the rectifier is connected to an anode of a third diode and to a cathode of a fourth diode; the third terminal is connected to the cathode of the first diode and to the cathode of the third diode; and the fourth terminal is connected to an anode of the second diode and to an anode of the fourth diode; a DC modulating control signal (23, 54) source output configured to provide a modulating voltage for controlling the actuator; a differential amplifier (26, 77) having a first input for receiving a first voltage measurable between the supply ground input and the device ground output, and a second input for receiving a second voltage measurable between the DC modulating control signal source output and the device ground output; and a linearization circuit comprising a transistor having an input connected to an output (38, 78) of the differential amplifier (26, 77) and having an output that can go to zero, wherein the output (38, 78) of the linearization circuit is configured to provide a signal down to zero for controlling the actuator; wherein the transistor comprises a field effect transistor having a gate connected to the output (38, 78) of the differential amplifier, a source connected to the second ground, and a drain connected to the output of the linearization circuit; and wherein the DC modulating control signal (23, 54) source output is connected across the second input of the differential amplifier (26, 77) and the supply ground input of the full wave rectifier (15, 57).