LESSON THIRTY-ONE. DISTRIBUTED CAPACITY AND CAPACITY LOSSES.Every coil of wire possesses the property, not only of carrying a current of electricity but ofholding a chargeof electricity as well. This property is called capacity. Thecapacityof a condenser is its property for holding a charge of electricity. The capacity of a coil is termed its "distributed capacity" in order to distinguish it from the capacity of a condenser. The distributed capacity of a coil is due to the condenser effect which exists between the adjacent turns of the wire. The effect of this distributed condenser is exactly the same as if a small condenser was connected across the ends of the coil as shown in the accompanying illustration.Distributed capacity is very objectionable in most receiving circuits because a radio detector depends upon voltage for its operation and when a circuit contains an appreciable amount of distributed capacity the voltage is considerably lower than it would be otherwise.The usual method of reducing the distributed capacity of a coil is to use wire having comparatively thick insulation so that the wires are spaced farther apart. Certain shellacs and varnishes used in impregnated windings increase the specific dielectric capacity of the space between the turns and increase the distributed capacity of the winding.The same objection to distributed capacity also holds good in the case of what might be termed capacity losses which are due to improperly arranged connections, contact points, etc. Every pair of leads or taps from a coil possesses capacity. They really form a miniature condenser, the wires corresponding to the tinfoil or metal sheets of the condenser and the air between being the dielectric.For that reason the leads should always be as far apart from one another as possible and contact points should be as small as possible. It is unwise to use "double conductor" having two parallel conductors bound together for leading out connections or connecting radio apparatus.If capacity losses and distributed capacity are reduced to a minimum in a circuit, it is possible to employ more inductance than would be otherwise in order to tune the circuit to a certain frequency and the voltage is thereby preserved and full benefit derived therefrom by the changes which it produces in the detector.
LESSON THIRTY-ONE. DISTRIBUTED CAPACITY AND CAPACITY LOSSES.Every coil of wire possesses the property, not only of carrying a current of electricity but ofholding a chargeof electricity as well. This property is called capacity. Thecapacityof a condenser is its property for holding a charge of electricity. The capacity of a coil is termed its "distributed capacity" in order to distinguish it from the capacity of a condenser. The distributed capacity of a coil is due to the condenser effect which exists between the adjacent turns of the wire. The effect of this distributed condenser is exactly the same as if a small condenser was connected across the ends of the coil as shown in the accompanying illustration.Distributed capacity is very objectionable in most receiving circuits because a radio detector depends upon voltage for its operation and when a circuit contains an appreciable amount of distributed capacity the voltage is considerably lower than it would be otherwise.The usual method of reducing the distributed capacity of a coil is to use wire having comparatively thick insulation so that the wires are spaced farther apart. Certain shellacs and varnishes used in impregnated windings increase the specific dielectric capacity of the space between the turns and increase the distributed capacity of the winding.The same objection to distributed capacity also holds good in the case of what might be termed capacity losses which are due to improperly arranged connections, contact points, etc. Every pair of leads or taps from a coil possesses capacity. They really form a miniature condenser, the wires corresponding to the tinfoil or metal sheets of the condenser and the air between being the dielectric.For that reason the leads should always be as far apart from one another as possible and contact points should be as small as possible. It is unwise to use "double conductor" having two parallel conductors bound together for leading out connections or connecting radio apparatus.If capacity losses and distributed capacity are reduced to a minimum in a circuit, it is possible to employ more inductance than would be otherwise in order to tune the circuit to a certain frequency and the voltage is thereby preserved and full benefit derived therefrom by the changes which it produces in the detector.
LESSON THIRTY-ONE. DISTRIBUTED CAPACITY AND CAPACITY LOSSES.Every coil of wire possesses the property, not only of carrying a current of electricity but ofholding a chargeof electricity as well. This property is called capacity. Thecapacityof a condenser is its property for holding a charge of electricity. The capacity of a coil is termed its "distributed capacity" in order to distinguish it from the capacity of a condenser. The distributed capacity of a coil is due to the condenser effect which exists between the adjacent turns of the wire. The effect of this distributed condenser is exactly the same as if a small condenser was connected across the ends of the coil as shown in the accompanying illustration.Distributed capacity is very objectionable in most receiving circuits because a radio detector depends upon voltage for its operation and when a circuit contains an appreciable amount of distributed capacity the voltage is considerably lower than it would be otherwise.The usual method of reducing the distributed capacity of a coil is to use wire having comparatively thick insulation so that the wires are spaced farther apart. Certain shellacs and varnishes used in impregnated windings increase the specific dielectric capacity of the space between the turns and increase the distributed capacity of the winding.The same objection to distributed capacity also holds good in the case of what might be termed capacity losses which are due to improperly arranged connections, contact points, etc. Every pair of leads or taps from a coil possesses capacity. They really form a miniature condenser, the wires corresponding to the tinfoil or metal sheets of the condenser and the air between being the dielectric.For that reason the leads should always be as far apart from one another as possible and contact points should be as small as possible. It is unwise to use "double conductor" having two parallel conductors bound together for leading out connections or connecting radio apparatus.If capacity losses and distributed capacity are reduced to a minimum in a circuit, it is possible to employ more inductance than would be otherwise in order to tune the circuit to a certain frequency and the voltage is thereby preserved and full benefit derived therefrom by the changes which it produces in the detector.
Every coil of wire possesses the property, not only of carrying a current of electricity but ofholding a chargeof electricity as well. This property is called capacity. Thecapacityof a condenser is its property for holding a charge of electricity. The capacity of a coil is termed its "distributed capacity" in order to distinguish it from the capacity of a condenser. The distributed capacity of a coil is due to the condenser effect which exists between the adjacent turns of the wire. The effect of this distributed condenser is exactly the same as if a small condenser was connected across the ends of the coil as shown in the accompanying illustration.
Distributed capacity is very objectionable in most receiving circuits because a radio detector depends upon voltage for its operation and when a circuit contains an appreciable amount of distributed capacity the voltage is considerably lower than it would be otherwise.
The usual method of reducing the distributed capacity of a coil is to use wire having comparatively thick insulation so that the wires are spaced farther apart. Certain shellacs and varnishes used in impregnated windings increase the specific dielectric capacity of the space between the turns and increase the distributed capacity of the winding.
The same objection to distributed capacity also holds good in the case of what might be termed capacity losses which are due to improperly arranged connections, contact points, etc. Every pair of leads or taps from a coil possesses capacity. They really form a miniature condenser, the wires corresponding to the tinfoil or metal sheets of the condenser and the air between being the dielectric.
For that reason the leads should always be as far apart from one another as possible and contact points should be as small as possible. It is unwise to use "double conductor" having two parallel conductors bound together for leading out connections or connecting radio apparatus.
If capacity losses and distributed capacity are reduced to a minimum in a circuit, it is possible to employ more inductance than would be otherwise in order to tune the circuit to a certain frequency and the voltage is thereby preserved and full benefit derived therefrom by the changes which it produces in the detector.