What causes residual flux?

When external magnetic force is applied to a magnetic material the domain magnetic moments align in the direction of applied force. However they will retain a net alignment in the direction of applied force, which is the cause for residual flux.

What is residual flux in DC generator?

The field of dc generator is an inherent characteristic of any electromagnet. Even after the current is turned off, the field still has some magnetism. Residual flux is what this flux is called. Residual flux is important in self excited generators.

What is residual flux in transformer?

Abstract: Part of the magnetic flux will remain in the transformer core after it is switched off, referred to as the residual flux. When an unload transformer being energized, inrush current may flow in the voltage jump side, causing relay malfunction and many other problems.

What is residual flux density?

Residual magnetic flux density (remanence) In the magnetic hysteresis loops showing the magnetic characteristics of a material, the remanence is the value of the flux density remaining when the external field returns from the high value of saturation magnetization to 0.

What is the function of residual magnetic?

Residual magnetism is defined as the amount of magnetization left behind after removing the external magnetic field from the circuit.

What is meant by leakage flux?

Leakage flux is defined as the magnetic flux which does not follow the particularly intended path in a magnetic circuit. The total flux in the magnetic circuit is given by, ϕ a = ϕ g + ϕ l.

Why residual flux is important for a DC shunt generator?

The switch in the field circuit is supposed open and the armature of DC Shunt Generator is driven at rated speed. Because of presence of small residual flux in the field poles, DC Shunt Generator will have a small voltage at its terminal even though the switch S is open when driven at rated speed.

What is residual voltage in DC generator?

The residual voltage is the voltage that remains in an output transistor while it is ON. For example, consider an NPN output with a power supply voltage of 24 V and a residual voltage of 2 V. While the output transistor is ON, there will be 2 V between the output line (the black wire) and the 0-V line (the blue wire).

What is a coercive force?

Definition of coercive force : the opposing magnetic intensity that must be applied to a magnetized material to remove the residual magnetism.

What is residual voltage?

The residual voltage is the voltage that remains in an output transistor while it is ON. For example, consider an NPN output with a power supply voltage of 24 V and a residual voltage of 2 V. A relay, timer, or other load is connected between the power supply line (the brown wire) and the output line (the black wire).

Where is residual magnetism found?

This phenomenon of the residual magnetism is widely seen in the transformers, generators, and motors. It is also called as Remanence.

What is the value of MMF?

The strength of the MMF is equivalent to the product of the current around the turns and the number of turns of the coil. As per work law, the MMF is defined as the work done in moving the unit magnetic pole (1weber) once around the magnetic circuit.

What makes no-clean flux residue benign?

If the No-Clean flux has been fully activated (experienced a temperature cycle commensurate with the flux or paste manufacturer’s solder profile recommendation), then the residue should be benign. Make sure that the outer extremities of the flux residue have indeed met the minimum required temperature to fully activate the flux.

Why do clean a no-clean flux?

Increasing PCB Complexity.

Improved Board Performance.

Improved Aesthetics.

Easier Inspection and Quality Control.

Better Conformal Coating Performance.

Early Specification.

Testing.

Follow the Process.

Check Materials Compatibility.

Choose Tools for Safety.

What is residual flux?

Residual flux is inherent characteristic of any electromagnet, including field of dc generator . In field of ideal electromagnet, flux is proportional to Ampere turns (field current multiplied by numbers of turns of the field winding).

What to remove solder flux?

Since solder flux for electronics are water soluble, regular water flux electronics can be used to remove the electronic solder flux residues taking care that the entire assembly needs to completely dried before power is applied to it.