LESSON FIFTEEN. THE HIGH POTENTIAL TRANSFORMER.The transformer, like the induction coil, steps up the voltage of the current to a value where it is sufficient to charge the condenser.The transformer for wireless work should have a potential of from 15,000 to 40,000 volts. Several manufacturers claim advantage for low voltages and build machines having a potential of only about 8,000 volts, but experiments have shown that under most ordinary conditions higher voltages permit greater range of transmission.Both open and closed core machines may be used with good results. Probably, however, neither one is the best.The core of a wireless transformer is built up of sheet iron "laminations" to reduce core losses and eddy currents.FIG. 33. High Potential Closed Core Transformer.FIG. 33. High Potential Closed Core Transformer.FIG. 34. Method of Protection against "Kick-Back"FIG. 34. Method of Protection against "Kick-Back"The secondary windings are very carefully insulated with empire cloth or paper and may or may not be immersed in oil accordingly as they are designed.A transformer, more especially than an induction coil, produces a "kick-back" on the line. "Kick-back" is a high potential current caused by the counter action of currents in the condenser and aerial system, due to the fact that they continue to surge after the current has dropped to zero or so low that it is unable of its own accord to produce secondary currents which will jump the spark gap."Kick-back" destroys insulation and is liable to cause burnouts of other electrical instruments supplied from the same system. It may be guarded against by providing the line with a protective device which consists of a condenser having a capacity of one or two micro-farads placed directly across the terminals of the transformer in series with two five-ampere fuses. A small spark gap open about 1/64 of an inch wide is connected across the terminals of the condenser.In case special protection is desired for some instrument in the circuit, such as a meter, a protective device should be connected directly across its terminals.
LESSON FIFTEEN. THE HIGH POTENTIAL TRANSFORMER.The transformer, like the induction coil, steps up the voltage of the current to a value where it is sufficient to charge the condenser.The transformer for wireless work should have a potential of from 15,000 to 40,000 volts. Several manufacturers claim advantage for low voltages and build machines having a potential of only about 8,000 volts, but experiments have shown that under most ordinary conditions higher voltages permit greater range of transmission.Both open and closed core machines may be used with good results. Probably, however, neither one is the best.The core of a wireless transformer is built up of sheet iron "laminations" to reduce core losses and eddy currents.FIG. 33. High Potential Closed Core Transformer.FIG. 33. High Potential Closed Core Transformer.FIG. 34. Method of Protection against "Kick-Back"FIG. 34. Method of Protection against "Kick-Back"The secondary windings are very carefully insulated with empire cloth or paper and may or may not be immersed in oil accordingly as they are designed.A transformer, more especially than an induction coil, produces a "kick-back" on the line. "Kick-back" is a high potential current caused by the counter action of currents in the condenser and aerial system, due to the fact that they continue to surge after the current has dropped to zero or so low that it is unable of its own accord to produce secondary currents which will jump the spark gap."Kick-back" destroys insulation and is liable to cause burnouts of other electrical instruments supplied from the same system. It may be guarded against by providing the line with a protective device which consists of a condenser having a capacity of one or two micro-farads placed directly across the terminals of the transformer in series with two five-ampere fuses. A small spark gap open about 1/64 of an inch wide is connected across the terminals of the condenser.In case special protection is desired for some instrument in the circuit, such as a meter, a protective device should be connected directly across its terminals.
LESSON FIFTEEN. THE HIGH POTENTIAL TRANSFORMER.The transformer, like the induction coil, steps up the voltage of the current to a value where it is sufficient to charge the condenser.The transformer for wireless work should have a potential of from 15,000 to 40,000 volts. Several manufacturers claim advantage for low voltages and build machines having a potential of only about 8,000 volts, but experiments have shown that under most ordinary conditions higher voltages permit greater range of transmission.Both open and closed core machines may be used with good results. Probably, however, neither one is the best.The core of a wireless transformer is built up of sheet iron "laminations" to reduce core losses and eddy currents.FIG. 33. High Potential Closed Core Transformer.FIG. 33. High Potential Closed Core Transformer.FIG. 34. Method of Protection against "Kick-Back"FIG. 34. Method of Protection against "Kick-Back"The secondary windings are very carefully insulated with empire cloth or paper and may or may not be immersed in oil accordingly as they are designed.A transformer, more especially than an induction coil, produces a "kick-back" on the line. "Kick-back" is a high potential current caused by the counter action of currents in the condenser and aerial system, due to the fact that they continue to surge after the current has dropped to zero or so low that it is unable of its own accord to produce secondary currents which will jump the spark gap."Kick-back" destroys insulation and is liable to cause burnouts of other electrical instruments supplied from the same system. It may be guarded against by providing the line with a protective device which consists of a condenser having a capacity of one or two micro-farads placed directly across the terminals of the transformer in series with two five-ampere fuses. A small spark gap open about 1/64 of an inch wide is connected across the terminals of the condenser.In case special protection is desired for some instrument in the circuit, such as a meter, a protective device should be connected directly across its terminals.
The transformer, like the induction coil, steps up the voltage of the current to a value where it is sufficient to charge the condenser.
The transformer for wireless work should have a potential of from 15,000 to 40,000 volts. Several manufacturers claim advantage for low voltages and build machines having a potential of only about 8,000 volts, but experiments have shown that under most ordinary conditions higher voltages permit greater range of transmission.
Both open and closed core machines may be used with good results. Probably, however, neither one is the best.
The core of a wireless transformer is built up of sheet iron "laminations" to reduce core losses and eddy currents.
FIG. 33. High Potential Closed Core Transformer.FIG. 33. High Potential Closed Core Transformer.
FIG. 33. High Potential Closed Core Transformer.
FIG. 34. Method of Protection against "Kick-Back"FIG. 34. Method of Protection against "Kick-Back"
FIG. 34. Method of Protection against "Kick-Back"
The secondary windings are very carefully insulated with empire cloth or paper and may or may not be immersed in oil accordingly as they are designed.
A transformer, more especially than an induction coil, produces a "kick-back" on the line. "Kick-back" is a high potential current caused by the counter action of currents in the condenser and aerial system, due to the fact that they continue to surge after the current has dropped to zero or so low that it is unable of its own accord to produce secondary currents which will jump the spark gap.
"Kick-back" destroys insulation and is liable to cause burnouts of other electrical instruments supplied from the same system. It may be guarded against by providing the line with a protective device which consists of a condenser having a capacity of one or two micro-farads placed directly across the terminals of the transformer in series with two five-ampere fuses. A small spark gap open about 1/64 of an inch wide is connected across the terminals of the condenser.
In case special protection is desired for some instrument in the circuit, such as a meter, a protective device should be connected directly across its terminals.