Circuit arrangement for call seekers in telephone systems
DE684326C
Circuit arrangement for private branch exchanges with dialer operation
DE620624C
Circuit arrangement for offer line selector in independent telephone systems
DE654149C
Circuit for private branch exchanges with a bidirectional connection line
DE595077C
Circuit arrangement for thermal relays in a daisy chain, especially in telecommunications systems
DE610374C
Circuit arrangement for automatic step control of the charging current of collector batteries
DE595236C
Circuit arrangement for telephone systems for displaying faults in unguarded sub-exchanges
DE562026C
Circuit arrangement, in particular for test purposes
DE562906C
Arrangement for checking the contacts of number discs
DE570436C
Circuit arrangement for telephone systems for automatic display of faults occurring in sub-exchanges in main exchanges
DE587499C
Circuit arrangement for control switchless line selectors in telephone systems
DE589312C
Circuit arrangement for the supply of private branch exchanges connected to telephone systems with dialer operation
DE587770C
Circuit arrangement for telephone systems for two-wire connecting lines
GB321466A
Apparatus for effecting a graphic recording accompanying the electrical impulse transmission, more particularly for automatic or semi-automatic telephone apparatus
DE544873C
Device for soldering the trigger pin in fuses
DE606238C
Device for graphical registration during the electrical current impulse
DE501010C
Circuit arrangement for automatic and semi-automatic telephone systems
DE496247C
Circuit arrangement for telephone systems with switching device for night operation
DE472763C
Circuit arrangement for coin telephones
GB275715A
Improvements in or relating to keyboard arrangements for automatic or semi-automatic telephone plants
