Adjustable voltage-clamping circuit

摘要

Disclosed is an adjustable voltage-clamping circuit (130). The voltage-clamping circuit comprises a bidirectional voltage clamp comprising at least one cold-cathode field emission electron tube (140). The bi-directional voltage clamp has an adjustable threshold voltage. First and second control grids (141, 142) are associated with the cold-cathode field emission electron tube which may form a tetrode. The grids are receptive of respective control signals for modulating the voltage in a main current-conducting path. The voltage clamp further comprises a circuit for biasing the voltage clamp’s said first and second grids to set said adjustable threshold operating voltage. The circuit may further comprise a one or more low pass filters (160). The cold-cathode field emission electron tube(s) may comprise electrodes of concentric cylindrical geometry.