Patent GB-433296-A (GB)
Title: Improvements in and relating to valve and circuit testing instruments and in adaptors for use therewith
IPC: G01R31/25
Filed: 1934-01-13
Abstract: 433,296. Thermionic valve holders. MACADIE, H. S., and AUTOMATIC COIL WINDER & ELECTRICAL EQUIPMENT CO., Ltd., Winder House, Douglas Street, Westminster. Jan. 13, 1934, No. 1317. [Class 39 (i)] [See also Group XXXVI] In a valve-testing instrument of the kind described in Specification 399,193, the valveholder on the base has a number of sockets greater than the number of pins (slidable and fixed) on the adaptor, which has side contacts corresponding in number to the number of sockets in the valve-holder in excess of the number of pins on the adaptor. One or more coupling-members may be provided to enable the device to be used with valves having any number of pins. As shown in Fig. 1, a valveholder a having seven sockets a<1>, a<2>, a<3>, a', a<5>, a<10>, a<11> is carried by a base b having terminals b<1>, b<2>, b<3>, b<4>, b<5>, b<6>, b<10>, b<11>, b<12>, b<13> and a four-way switch c having four pairs of fixed contacts which are normally in contact with one another but which are separated by the arms of the switch when in engagement therewith. The terminals b<12>, b<13> are connected to the insulated moving contact arms of the switch c, the other terminals being connected to the sockets of the holder a as shown. A current measuring instrument connected to the terminals b <12>, b<13>, may be inserted between different pairs of contacts by setting the switch c to the corresponding position. Carried by an eight-way connecting cable e is an adaptor f having four fixed pins f<1>, f<5>, f<10>, f<11> and a slidable fifth pin f and also a pair of contacts f<4>, f<3>, to which two of the leads of the cable e are connected. The other leads of the cable connect the pins of the adaptor f to the corresponding sockets on the holder a, one lead connecting the crocodile clips d<1>, d<2>. A secondary adaptor n, Fig. 2, has on its underside seven pins adapted to fit the sockets of the valve-holder a, and on its top five sockets adapted to receive a five-pin valve, the corresponding pins and sockets being connected, and the remaining two pins being connected to spring contact strips p<3>, p<4>, adapted to engage the contacts f<3>, f<4> on the adaptor f when this is plugged into the member n. Insulated capped screws x<3>, x' are also provided. For testing a valve having more than seven pins, a pair of complementary coupling members n<1>, n<2>, Fig. 4 are connected to the adaptor f and the valveholder a respectively. The member n<1> has on its underside nine pins adapted to fit into a nine-socket valve-holder and on its top side five sockets adapted to receive the pins of the adaptor f, two spring contacts t<3>, t<4> being provided to engage the contacts f<3>, f<4> on the adaptor f. The sockets and the contacts t<3>, t<4> are connected to the corresponding pins, the remaining two pins being connected to side contacts t<7>, t<8>. The member n<2> has on its upper surface nine sockets, arranged to take the pins of a nine-pin valve, and on its underside seven pins arranged to fit the sockets of the valve-holder a. The pins are connected to the corresponding sockets, the remaining two sockets being connected to side terminals v<7>, v<8>. The contacts t<7>, t<8> are connected to the contacts v<7>, v<8> by means of a twin core cable w. For testing valves with four or five pins, or the circuits associated therewith, the member n is plugged into the valve-holder a thereby converting the apparatus into that described in Specification 399,193. When used for seven-pin valves, the adaptor f is plugged into the coupling member n and the two parts are used as the adaptor, the valve being inserted into the holder a and the twopart adaptor f, n being plugged into the set. By loosening the screws x<3>, x<4>, the circuits between the blades p<3>, p<4> and contacts f<3>, f<4>, may be broken and completed through a measuring instrument. When used for nine pin valves, the adaptor f is plugged into the member n<1> which is inserted into the valveholder in the set. The member n<2> is inserted into the valve-holder a, the valve being plugged into the member n<2>. The complementary coupling members may be arranged for use with valves having more than nine pins, the additional elements being connected by a cable.