GB247953A - Improvements in electrical signalling devices - Google Patents

Abstract

247,953. Huizinga, M. J., (Assignee of Lier, S. K. D. M. van). Feb. 18, 1925, [Convention date]. Checking receipts. - Indicating-apparatus for use in combination with an electrically - operated bidding - apparatus comprises a plurality of indicators, the operation of any one of which renders the remaining indicators inoperative until the energizing circuit of the operated indicator is opened. The highest bidder is thereby indicated with more certainty in so far as the risk of an incorrect order of transmission of signals is minimized. The system comprises a plurality of electric discharge tubes g<1>, g<2>, g<3>, &c., each controlled by a push and connected in series with a resistance w to a direct or alternating supply. As soon as any one of the tubes is operated, current passes through the resistance w and in consequence the voltage across the tube falls, to a value such that the discharge through the operated tube is maintained, but operation of any one of the remaining tubes is impossible. The resistance w may be replaced by a relay which stops the bidding apparatus when any one of the discharge tubes is operated. Alternatively the potential difference across the resistance w may be impressed upon a thermionic valve, the plate current of which operates the braking device of the apparatus. The operated contact may also be retained in its operative position by a spring pawl until released by the operator or by an electromagnet controlled by the auctioneer.