A power supply for supplying power in high external magnetic fields, the power supply comprising: at least one regulator module; and a piezoelectric core converter module having one or more piezoelectric transformers, wherein the regulator module is configured to regulate the flow of AC line power to the piezoelectric core converter module by converting the AC line power to a DC power, and to provide the DC power to the piezoelectric core converter module, wherein the regulator module comprises a microcontroller module, wherein the piezoelectric core converter module comprises an H-bridge configured for receiving the DC power from the regulator module and for generating a high frequency pulse train from the DC power, the high frequency pulse train being duty cycle controlled by the microcontroller module to generate a constant root mean square, RMS, voltage and being provided to the one or more piezoelectric transformers, wherein the piezoelectric core converter module is configured for converting the high frequency pulse train to isolated DC output power at a predetermined voltage using the one or more piezoelectric transformers, and wherein the microcontroller module is further adapted to monitor the isolated DC output power thereby to adjust the frequency of the high frequency pulse train in order to regulate the voltage of the isolated DC output power to a constant DC voltage regardless of output load variations. at least one regulator module; and a piezoelectric core converter module having one or more piezoelectric transformers, wherein the regulator module is configured to regulate the flow of AC line power to the piezoelectric core converter module by converting the AC line power to a DC power, and to provide the DC power to the piezoelectric core converter module, wherein the regulator module comprises a microcontroller module, wherein the piezoelectric core converter module comprises an H-bridge configured for receiving the DC power from the regulator module and for generating a high frequency pulse train from the DC power, the high frequency pulse train being duty cycle controlled by the microcontroller module to generate a constant root mean square, RMS, voltage and being provided to the one or more piezoelectric transformers, wherein the piezoelectric core converter module is configured for converting the high frequency pulse train to isolated DC output power at a predetermined voltage using the one or more piezoelectric transformers, and wherein the microcontroller module is further adapted to monitor the isolated DC output power thereby to adjust the frequency of the high frequency pulse train in order to regulate the voltage of the isolated DC output power to a constant DC voltage regardless of output load variations. wherein the regulator module is configured to regulate the flow of AC line power to the piezoelectric core converter module by converting the AC line power to a DC power, and to provide the DC power to the piezoelectric core converter module, wherein the regulator module comprises a microcontroller module, wherein the piezoelectric core converter module comprises an H-bridge configured for receiving the DC power from the regulator module and for generating a high frequency pulse train from the DC power, the high frequency pulse train being duty cycle controlled by the microcontroller module to generate a constant root mean square, RMS, voltage and being provided to the one or more piezoelectric transformers, wherein the piezoelectric core converter module is configured for converting the high frequency pulse train to isolated DC output power at a predetermined voltage using the one or more piezoelectric transformers, and wherein the microcontroller module is further adapted to monitor the isolated DC output power thereby to adjust the frequency of the high frequency pulse train in order to regulate the voltage of the isolated DC output power to a constant DC voltage regardless of output load variations.