Abstract: Disclosed herein is an arrangement for shielding individual electronic units from undesired microwave or millimeter wave radiation while providing a means of transferring input and output signals and operating power through the shield wall. A metal box encapsulates an electronic unit. Input and output signals are fed into and transferred from the electronics unit through the shield wall using optical links and photo transmitting and receiving components. Power is transferred through the shield box wall using piezo crystals secured to the outside and inside of the shield box wall and a dielectric rod connected between the two piezo crystals through a hole in the wall. Electrical energy therefore can be transferred into mechanical energy transferred through the box wall to the piezo crystal within where it is received and transferred back into electrical energy. Accordingly, metal feedthroughs are not needed, eliminating any paths for radiation to enter the shield box.

Abstract: A dual mode flyback power supply 10 capable of automatically transitioning between operational modes in response to changes in the impedance of a load 12 connected thereto. The dual mode power supply 10 of the present invention includes an input voltage source 15 for providing input voltage and current. The power supply 10 also includes a first transformer 20 having primary N1, secondary N2 and tertiary N3 windings for supplying a first current to a load 12 operatively coupled to the secondary winding N2. The primary winding N1 is coupled to the input voltage source 15. A feedback circuit 50 provides a first signal in response to the current through the load 12 and a second signal in response to the load voltage exceeding a threshold voltage. The power supply 10 of the present invention further includes a switch 30 for controlling the input current through the primary winding N1 of the first transformer 20 in response to the first and second signals.