Resistances. 



169 



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50 862. 1 : 8. 



50867. 1:15. 



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 5 





The preceding, for a 25 Ampere Direct Current Arc Lamp. * - d. 



List Xo. 50,876 50.877 50.877 a 50,877 b 

 Working Pressure 65 110 150 220 volts 



Price 1. 10. 2. 10. 4. 0. 6. 0. 



50.878. Switchboard for connecting up the Projection Apparatus with the wall, Figure, 



can be used for current of up to 30 amperes. Price without series resistance ... 1. 10. 



50.879. do., for connecting up the Projection Apparatus with the ceiling 1.10. o 



"'. ^80. Transformer for Alternating Current Arc Lamps of up to 25 amperes with a working 



voltage of 100 125 volts, with contact resistance 3. 0. 



When using alternating current, it is under all circumstances advisable in view of the great 

 saving of current to provide a transformer for stepping down the network voltage to that of the lamp. 

 Separate series resistances are thus done away with. When submitting orders, kindly state precisely 

 the network voltage. 



We would ask that series resistances and transformers be ordered at the same time as the lamp, 

 so that the two can be regulated together, this greatly simplifying erection and working. 



"xi. 881. -The preceding, for working pressures of from 190 220 volts, for 1 arc 



lamp to 20 amperes 3. 5. 



50,882. Mercury Vapour Alternating Current Rectifier (Cooper-Hewitt's), Figure, for a 



D. C. output of 30 amperes, with automatic starter 25. n. n 



Flexible Double Conducting Cable, armoured, for connecting the lantern with the switchboard. 



List Xo. 50,883 50 884 50,885 50,886 50,887 



Section, abt. sq. mm 2.5 4 6 10 16 



Permissible load 15 20 i':> 35 60 amps. 



Price per metre 1 s. 6 d. 1 s. 8 d. 2 s. d. 3 s. d. 4 s. d. 



The two thickest sections are suitable for the Megadiascope and Epidiascope. 



Cl. 3270. 242. 

 3462. :>2:>9. 



