GB371939A - Improvements in electric potential dividers - Google Patents

Abstract

371,939. Current and pressure meters. BURCH, F. P., Park House, Atkinson Road, Sale, Cheshire, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. Jan. 30, 1931, No. 3087. [Class 37.] For the purpose of reducing distortion due to stray capacity effects in a potential divider wherein division of voltage is effected by resistances or by resistances and series condensers and provided with a delay cable, the current carried by the divider is increased so as to reduce the importance of the capacity effects, by constituting the divider of a high voltage and a low voltage resistance 9, 10 in series, the latter being located, with the former, at the input end of a two-conductor delay cable 5, 6, 7 which is connected across the low voltage resistance 10, the low voltage or output terminals 3, 4 being located at the other end of the cable, and inserting a third resistance 11 in the lead from the junction of the high and low voltage resistances to the corresponding low voltage output terminals 3. The effect of the resistance 11 is to prevent reflection of the signal and the Specification gives formulµ for determining its value. Alternatively, the high and low voltage impedances 9, 10 may each comprise a resistance in series with a condenser and part of the impedance 10 may be disposed at the output end of the delay cable in the form of a resistance and a condenser connected across the terminals 3, 4. In the latter case the impedance 11 may be connected at the output end of the delay cable. A condenser 12 may be connected across the resistance of the low voltage impedance to reduce further the effect of stray capacity. The device is particularly applicable to cathode ray oscillographic measurements in which the time sweeping movement is initiated before the arrival of the wave to be recorded. Specification 371,938 is referred to.