Popular Science Monthly 



A New Condenser to Protect 

 Wireless Generators 



IF a layman were shown about the 

 wireless cabin on board a battleship, 

 without a doubt he would consider the 

 rack of condensers about the least im- 

 portant part of the equipment. The 

 experienced amateur knows better. He 

 knows that should the condensers break 

 down, the entire sending machinery is 

 likely to collapse. Even leaking con- 

 densers may cut down the efficiency of 

 the station so that it would be difficult, 

 if not impossible, to comunicate over a 

 long distance. Think what this would 

 mean if a warship were on a scouting 

 cruise and discovered something im- 

 portant ! 



Though it is not generally known, an 

 accident such as this was always threaten- 

 ing to isolate the ships of a fleet, not very 

 much more than a year ago. Most ships 

 were using glass Ley den jars or glass 

 plate condensers at this time. The im- 



A condenser built of several units, which 

 are insulated from one another as well 

 as each of the plates within each unit 



mense voltages across the high-tension 

 transformer that the jars had to stand, 

 continually broke them down under the 



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prolonged strains, and only protective 

 condensers across the wireless generator, 

 saved it from utter destruction. Moreover, 



The same method is used in this condenser, 

 although it is of very different construction 



brush discharges invariably took place 

 through the glass of the condensers. 

 These discharges increased in intensity 

 as the glass weakened with use. The dis- 

 charges contaminated the air with ozone, 

 which made it hard for the operators to 

 work; to say nothing about the decrease in 

 the sending power that they produced. 



The Navy Department has now elimi- 

 nated the glass condenser, and thus has 

 done away with its disadvantages. A 

 mica condenser, the development of 

 William and Philip Dubilier, of New 

 York city, is now used exclusively. This 

 condenser is made up of a number of 

 units connected together in series. The 

 result is that the full potential across the 

 transformer is divided a good number of 

 times before it acts across any of the 

 units. The voltage that does result 

 across a single condenser is correspond- 

 ingly sm.all; too small, in fact, to set up 

 any detrimental brush discharge action. 

 Such sets of condensers ought to be highly 

 efficient, and, theoretically, ought to last 

 a life time. 



Each of the units is built up of al- 

 ternate sheets of copper foil and mica, 

 the copper foil being connected in mul- 

 tiple as in ordinary mica condensers. 

 Though the probability of a breakdown 

 of the mica has been made exceedingly 

 small, the chances of such a breakdown 

 injuring the station has been made 



