253,266. Dubilier Condenser Co., Ltd., (Deventer, H. R. van). April 1, 1925. Wired wireless systems; receiving systems and apparatus.-Relates to a wired wireless system of the kind described in Specification 220,667, in which one or more of a number of high-frequency currents which are normally excluded from a particular circuit by a corresponding number of blocking circuits, is or are admitted to this circuit for a predetermined time by coin actuation of switching means which operates to short-circuit one or more of the blocking circuits. The present invention consists in apparatus for use in a. wired wireless system of this kind and in certain modifications the coin actuation mav be effected at a distance. Fig. 1 shows a construction in which the coin operates to short-circuit all the blocking circuits, all the high-frequency currents passing over the conductors 1, 2 being admitted to the receiving set 6 for a predetermined time, the set being tuned to the particular frequency required. The blocking circuits each comprise an inductance C<1>, C<3>, C<5> and C<2>, C<4>, C<6> in series with the conductors 3, 4 respectively, and secondary circuits comprising secondary coils C<1>, C<3>, C<5> and C<2>, C<4>, C<6> inductively coupled to the primary coils, and condensers K<1>, K<3>, K<5> and K<2>, K<4>, K<6>, each secondary circuit being tuned to one of the high-frequency currents. Condensers K<7>, K<8> are bridged across the conductors 3, 4 with an intermediate earth connection. The time measuring device comprises a shunt motor having a field winding 8 arranged across the conductors 3, 4 and an armature winding 9 having an adjustable resistance 28 connected in series therewith. The motor armature 9 drives a shaft 10 which rotates a second shaft 11 through suitable reduction gearing. The shaft 11 carries discs 12, 13 upon which are mounted commutators having an insulating portion 15 ,19 and conducting portion 14, 18 respectively. Brushes 16, 17 and 20, 21 normally rest upon the insulating portions of the commutators. When a coin 25 is inserted between the contact springs 23, 24, a circuit is completed so as to put the motor in operation from conductor 4, winding 9, spring 24, coin 25, spring 23, resistance 28 to conductor 3. The motor then drives the shaft 11, the brushes 16, 17 and 20, 21 passing from the insulating portions of the commutators on to the conducting portions, thus completing a circuit from conductor 1 through conductor 30, brush 20, segment 18, brush 21, conductor 31 to receiving set 6 and back through conductor 32, brush 16, segment 14, brush 17 and conductor 33 to conductor 2. The blocking circuits are thus short-circuited until a projection 22 of conducting material on the disc 13 forces the coin 25 out of the springs 23, 24, the motor circuit being broken as soon as the projection 22 is clear of the springs. The insulating portions of the commutators are then beneath the brushes 16, 17 and 20, 21 once more and the blocking circuits are no longer short-circuited. Fig. 2 shows a similar construction to that shown in Fig. 1, but in which a spring pile-up 38 - - 41 is associated with each of the blocking circuits F<1>, F<2>, F<3>, a coin 25 being inserted in a particular spring pile-up so as to short-circuit the blocking circuit associated therewith and allow only the corresponding high-frequency current to pass to the receiver 6 for a predetermined time. In this construction the shaft 11 carries coinejecting fingers 35, 36, 37, one for each spring pile-up, instead of the discs 12, 13, Fig. 1. Fig. 3 shows the arrangement of the apparatus shown in Fig. 2 in a box 45 together with a modified coin-ejecting arrangement. The motor and reduction gears are housed in a box 50, the motor driving a shaft 51 on which are rotatably mounted discs 52, 53, 54, each of which carries a coin-ejecting finger. The discs are coupled to the shaft by spiral springs 56 so that, should the ejecting fingers encounter an obstacle, the discs are held stationary whilst the shaft continues to rotate and stores up energy in the springs 56. A cam 57 on the shaft 51 is adapted to co-operate with a finger 58 on an auxiliary shaft 59 carrying pawls 60, 61, 62 normally riding on the peripheries of the discs 52, 53, 54. On insertion of a coin 25, the motor rotates the shaft 51 and discs 52, 53, 54 until the ejecting finger 50 is about to strike the coin 25, when the pawls 60, 61, 62 drop into notches in the peripheries of the discs and lock the latter against further rotation. The shaft 51 continues to revolve until the cam 57 strikes the finger 58 so as to rock the shaft 59 upwardly and disengage the pawls from the notches in the discs. The energy stored up in the springs 56 then causes the ejecting fingers to snap round, the finger 55 ejecting the coin 25 and following it through the contact springs. Modifications of the arrangements shown in Figs. 1 and 2 are described in which the coin actuation is effected at a distance, the insertion of a coin operating a solenoid to cause one of a number of contact arms on a rotatable disc to engage between the springs 23, 24, Fig. 1, or spring pile-up, Fig. 2. After the elapse of a predetermined time, the projection 22, Fig. 1, or the appropriate finger 35, 36, or 37, Fig. 2, ejects the contact arm and causes it to engage a contact stud so as to complete a circuit through a coin-collect magnet and thus release the coin. In these modifications the spring pile-up or pile-ups for the coin and the coincollect magnet or magnets may be housed in a suitable container provided with a single coin slot for the Fig. 1 arrangement and a number of coin slots, each representing one of the frequencies for which corresponding blocking circuits have been provided, for the Fig. 2 arrangement. The service meter 34 shown in Fig. 2 and box 45 may be enclosed in a common box secured by a padlock.