Dynamic matching device for thin-film resistors - has HF electrode supplied via HV capacitor and arc-trimming resistance layer

摘要

The matching device, for dynamically adjusting the value of a thin-film resistor, has a Tesla transformer coupled over an h.v. capacitor to a rod electrode. The electrode is situated above the resistance layer and arc-trims the latter to its required value whilst the resistance is being continuously monitored. The frequency of the transformer's current lies around 1 MHz. More than one electrode may be used; and their distance from the resistance layer is 0.1 to 1 mm. The H.V. capacitor lies in the range 0.1 to 5 pF, normally 0.5 to 3 pF, changes the discharge current. By the use of one or several discharging electrodes with points or knife edges with small distancing from the resistance layer, to advantage 0.1 to 1 mm, uncontrolled jumping of the discharging sparks is avoided.