Patent ID: 8688279

Claim:
A radar level gauge using microwaves for measuring a filling level of a product in a tank, comprising: a microwave unit for transmitting microwaves into the tank, and receiving a reflection from the tank, processing circuitry connected to said microwave unit and arranged to determine said level based on a relation between transmitted microwaves and said reflection, a power interface for connecting said radar level gauge to an external power supply, and power management circuitry arranged to provide power at an operating voltage to said microwave unit and said processing circuitry, said power management circuitry including: a first voltage converter, having a low-voltage end for receiving a drive voltage from said power interface and a high-voltage end for supplying an intermediate voltage higher than said operating voltage, a temporary energy store arranged to be charged by said intermediate voltage, a second voltage converter, having a high-voltage end for receiving an input voltage from said energy store, and a low-voltage end for providing said operating voltage lower than said input voltage.