Abstract: An example apparatus operable to provide power to a transducer via a regulator output, the power regulator comprising: filter circuitry including a filter input and a filter output, the filter output coupled to the regulator output; amplifier circuitry including an amplifier input and an amplifier output, the amplifier output coupled to the filter input; sensing circuitry including a sensing input and a sensing output, the sensing input coupled to the filter output and the regulator output; and a controller including a controller input coupled to the sensing output and including a controller output coupled to the amplifier input, the controller configured to: supply an excitation signal to the amplifier circuitry to cause the amplifier circuitry to supply the power based on the excitation signal; estimate a magnitude of the power based on measurements of current and voltage at the filter output.