116 



Experimental Switchboards and Experimental Resistances. 



No. 50 47:1 



50.473. Experimental Switchboard, Type Bi, for fixing to wall (cf. Fig. 50,471), for connecting i s. d. 

 up to 220 volts Direct Current, for taking currents of 0.04 20 amps, and pressures 



of 0.4 220 volts from the mains, with standard pattern instruments and Double Switch 

 Contact having 30 stages 24. 5. 



Weight, net, about 82 kg; gross, about 125 kg. For dimensions, see dimension sketch and table 

 on p. 113. Packing for land transport 0. 15. 



The switchboard carries: 1 regulating resistance of 48 ohms, variable in 30 steps, for a max. load 

 of 5 20 amps., with Double Switch Lever having 30 contacts; 2 terminals for connecting up to the 

 network; 2 fuses; 1 main switch (quick break type); 1 dead-beat standard ammeter; 2 measuring resis- 

 tances; 1 ammeter switch; 1 dead-beat standard voltmeter; 1 voltmeter switch ; 1 switch for the shunt 

 for potential-distribution; 1 plug box with plug and 4 m flexible. 



For currents to 30 amperes Extra 3. 10. 



Fitting a Lamp Bracket for lighting purposes, with switch and 2 fuses Extra 1. 0. 



Portable Construction as in Fig. 50,471 A Extra 0. 10. o 



Sliding Rheostat fitted to the slab, adaptable up to 20 amps., having a resistance of 0.9 ohm . . . Extra 1. 5. o 



Rheostat and Double Switch Contact arranged separately from the board and made of travelling type (see 



Fig. 50,471 B) Extra 5. 0. 



Measuring Instruments with 2 ranges (cf. F i g. 50,471 C), permitting of accurately measuring small cur- 

 rents also Extra 2. 10. 



The ranges are 30 and 3 amps, and 250 and 25 volts. 



50.474. Travelling Type Experimental Switchboard (Type Bi), (cf. Fig. 50,472), fitted with 

 massive castors; apparatus and measuring instruments as in No. 50,473 26. 5. 



Weight, net, about 100 kg, gross, about 145 kg. Packing for land transport 0. 16. o 



50.475. Experimental Switchboard Type Ci, for fixing to a wall (cf. F i g. 50,471). for con- 

 necting up to 110 volts Direct Current, and for taking currents of 0.04 20 amps, and 

 pressures of 0.4 110 volts from the network; with standard pattern instruments and 

 Double Switch Contact Current Eegulator with 21 stages 19. 0. 



Weight, net, about 50 kg; gross, about 75 kg. For dimensions, see dimension sketch and table 

 on p. 113. Packing for land transport 0. 12. 



The switchboard carries: 1 24-ohm regulating resistance variable in 21 stages, and for a max. load 

 of 5 20 amps., with Double Switch Contact having 21 contacts; 2 terminals for the feed supply; 

 2 fuses; 1 main switch (quick break type); 1 dead-beat standard ammeter; 2 measuring resistances; 

 1 ammeter switch; 1 dead-beat standard voltmeter; 1 voltmeter switch; 1 switch for the shunt for 

 potential-division; 1 plug box with plug and 4 m flexible. 



Fitting a Lamp Bracket for lighting purposes, with switch and 2 fuses Extra 1. 0. 



Portable Construction (cf. Fig. 50,471 A) Extra 0.10. 



Sliding Rheostat, fitted on the slab, adaptable up to 20 amps., with resistance of 0.9 ohm Extra 1. 5. 



Resistance and Double Switch Contact arranged separately from the switchboard and made of travelling type ! 



(see Fig. 50,471 B) Extra 5. 0. 



Measuring Instruments with 2 ranges (cf. Fig. 50,471 C), to admit also of measuring exactly small currents | 



and pressures Extra 2. 10. 



The ranges are 20 and 2 amps, and 110 and 11 volts. 



50.476. Travelling Type Experimental Switchboard, Type Ci (cf. Fig. 50,472), fitted with 

 massive castors; apparatus and instruments exactly as in No. 50,475 21. 0. 



Weight, net, about 68 kg; gross, about 100 kg. Packing for land transport 0. 13. 



50.477. Experimental Switchboard, Wall Type, with extra large Standard Measuring Instru- 

 ments, two Switch Contacts arranged separately and resistance for placing over the 

 switchboard (Figure), for connecting up to 110 160 volts Direct Current, for taking 

 currents of 0.03 30 amps, and pressures of 0.3 110 (or 160) volts from the main . 37.10.0 



The instrument bases are 295 mm diameter. It is possible to read the scale even at a consi- 

 derable distance away. The levers (or handles) of the Double Switch Contact used in our other switch- j 

 boards are fixed separately, and there is a separate circuit for each lever. The resistances are not ; 

 placed behind the switchboard but over the latter, being connected to the switchboard by special leads. 



The switchboard is fitted with: 1 Regulating Resistance of 36 ohms in 30 steps, for a max. load 

 of 5 30 amps, and two switch levers each with 30 contacts; 2 fuses; 1 main switch; 1 dead-beat stan- 

 dard type ammeter with 2 measuring resistances and 1 dead-beat standard type voltmeter, each in- 

 strument having a diameter of base of 295 mm; 1 ammeter switch; 1 voltmeter switch; 1 switch for 

 the shunt for potential-division; 1 lamp bracket with 2 fuses; 1 plug box with plug and 4 m flexible; 

 also terminals for main and apparatus. 



50,477 a. - The preceding, for connecting to a 220 volt Direct Current main, for 



taking currents of 0.04 20 amps, and pressures of 0.4 220 volts from the network 38.10.0 



The resistance is 48 ohms in 30 stages for a max. load of 5 20 amps. ; in other respects the con- 

 struction is the same as that of Switchboard No. 50,477. 



