[or 



Handy Man 



Electric Lights for the Summer Cottage' 



IN the selection of a generating equip- 

 ment for the charging plant of the 

 summer cottage, the worker has a num- 

 ber of options. For instance, he may in- 

 vestigate the claims made for the many 

 small generating units consisting of 

 dynamo and gasoline engine either direct 

 connected or belt driven. While these 

 little plants are perhaps high in price for 

 our purpose, still they have many fea- 

 tures of merit which commend them to 

 the notice of the amateur engineer in 

 charge. On the other hand, the ingenious 

 man may couple together a small engine 

 and dynamo, mounting them on a single 

 wooden base, and perhaps get quite as 

 satisfactory results as the other fellow 

 who put a hundred or two into a regula- 

 tion plant. This article is intended for 

 the handy man who, for some reason or 

 other, scorns the idea of purchasing the 

 plant complete, and who wishes, perhaps, 

 to pick his engine from some place near 

 the junk heap and to rewind an old fan 

 motor to make his generator. This very 

 thing has been done, and that more than 

 once within the knowledge of the writer. 

 To this end, therefore, let us consider 

 the amount of electrical energy neces- 

 sary to charge the battery and after that 

 the horsepower required to get this en- 

 ergy out of the dynamo. 



The battery suggested in former arti- 

 cles is of a capacity ranging from 80 to 

 100 ampere hours and its charging rate 

 is in the neighborhood of 10 amperes 

 for from eight to twelve hours. A gen- 

 erator having a capacity of 100 watts 

 will do the work if this capacity is actual 



* Continued from the July number. 



as well as theoretical. The voltage should 

 be in the neighborhood of eight or nine 

 and the machine should be capable of 

 standing a continuous run of twelve 

 hours, delivering a current of ten am- 

 peres without overheating either in the 

 windings or the bearings. Perhaps the 

 most prolific source of trouble in the 

 small machine is found in the bearings, 

 which are seldom well designed and fre- 

 quently without adequate oiling facilities. 

 Of course, the ideal generator for our 

 purpose is one of the standard automo- 

 bile lighting and charging type. It is 

 likely that the cost of a new one will 

 scarcely be justified, and, unless the 

 worker is able to buy a second-hand gen- 

 erator in good condition, it is probable 

 that he will be obliged to have recourse 

 to a dynamo of inferior design. 



In the writer's experience one of the 

 most^ satisfactory small generators avail- 

 able is one made from a rewound small- 

 power motor. The case of a one-eighth 

 horsepower machine of this type is re- 

 called. The motor was picked up in a 

 junk shop at a price commensurate only 

 with the iron and copper in it, and, while 

 the windings were quite worthless since 

 they had been literally burned up, still 

 the frame, bearings, armature and com- 

 mutator were in excellent shape after 

 the dust and oil were cleaned off. The 

 machine had originally been wound for 

 no volts and of the shunt type. In re- 

 moving the winding, or rather its rem- 

 nant, the sizes of the wire on armature 

 and field were carefully noted and in 

 rewinding there was used a wire having 

 ten times the area of the original one. 

 The carbon brushes of the motor were 

 displaced by ones of copper gauze and 



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