inductance of a solenoid with ferrite rod core

Rdc=DC resistance of the wire used in the solenoid Ra*(FDF-1)=additional series resistance caused by increased average flux density around the conductors when a ferrite core is placed inside the solenoid Ra=series RF resistance of solenoid in air Lp=parallel inductance representing the increase of inductance caused by the ferrite core. It has a suffix'a' when referring to the solenoid in air, and a suffix'f' when referring to a solenoid having a ferrite core. When the solenoid conductors are bathed in magnetic flux. LFEF=leakage flux effect factor, the ratio of Lp to µi*La.

The 'a' denotes air surrounding the solenoid, the 'f' denotes the inclusion of a ferrite core. This is a number, greater than 1, that corrects the value of the series DC resistance of the solenoid to its actual AC value. Another part of Co is made up of capacitance from the hot parts of the solenoid through air, to ground.įDF(suffix a or f)=flux density factor. If a solenoid former is used, its dielectric is in the path and will affect the overall loss. This is made up of mostly capacitance from the hot parts of the solenoid, through the ferrite dielectric, to ground (assuming that one end of the solenoid is grounded). The sixth part discusses important info about ferrite 61 and similar materials.ĬLF=ferrite core loss-factor at a specific frequency Ĭo=distributed capacitance. The fifth part shows how Q varies when the ratio of the length of the solenoid to the core changes Also shown is a chart showing the change of Q when the conductor spacing is changed. It also includes simulations showing the distribution of magnetic flux density and current density in the turns of the solenoid. The third part displays graphs of flux density, flux lines, inductance and Q of several ferrite cored inductors. The fourth part shows how flux density changes when an air gap is inserted in the center of a ferrite rod. The second part describes several ferrite cored inductors, along with measurements A simplified model and an equivalent circuit is also discussed.

One of this Article identifies and comments upon some of them. Summary: Many factors interact to affect the Q of ferrite rod cored inductors. About Maximizing the Q of solenoid inductors that use ferrite rod cores, including charts of magnetic flux density and flux lines, with some actual Q and inductance measurements from simulations in FEMM

Inductance of a solenoid with ferrite rod core