[SOLVED] - How to test field windings & armature windings of the …
Oct 11, 2011 · Activity points. 10,827. Few tips when you check the brushed dc-motor, -disconnect all wires from motor -turn motor slowly with hand and check is the rotor turning without jamming or stucking ....if so >> mechanical fail ... check bearings ...is field magnet loose...other loose parts. Try to move the motor shaft axial and radial directions to ...
How to test a DC Shunt motor ? What tests should be performed
Oct 14, 2012 · first test the field winding with a megohmmeter to check, that the winding has no short to the housing. Then check the current consumption of the field winding. If you can, start with a low voltage and rise it until you reach the nominal voltage. Look for the maximum current at the specification plate.If you reach the maximum current before the ...
Regulating a dynamo (DC generator) output to charge a battery
Oct 7, 2009 · When the relay pulls in, power was cut to the field winding, and the output power starts do decrease. The relay sparks and buzzes away merrily controlling the output voltage. That is the general idea. A modern electronic voltage regulator works exactly the same way, but the switching on and off of the field winding is done electronically.
Self Excitation and Residual Magentism in a DC Motor
Oct 16, 2005 · Self-excitation works this way: the residual flux in the stator is sufficient for the generator to develop an output voltage. If the field (excitation) winding is connected in parallel with the output, then the voltage produced at the output will create a current through the field winding, which will increase the field (assuming the polarity is ...
what is VS coupling or VSD coupling ? thanks - Forum for Electronics
Oct 11, 2011 · determines the torque transmitted from the input rotor to the output rotor. The controller provides closed loop speed regulation. by varying clutch current, only allowing the clutch to transmit enough torque to operate at the desired speed. Speed feedback is typically provided via an integral AC tachometer.
modulating only the magnetic field of an EM wave - Forum for …
Jan 29, 2004 · Its magnetic field is present and detectable outside the aluminium/copper/whatever 'E-shielding' box. Applying RF to its superimposed winding, the static magnetic field would vary per the waveform, sort of 'modulated'. Outside the box, there will be the same static magnetic field with no magnetic 'modulation'; inside the box, yes.
How to make an air gap on an E E core? | Forum for Electronics
Dec 23, 2010 · If you want lowest stray field, and the winding is over the middle leg, you should have the gap in the middle leg only. In case of a single prototype only, you can grind the gap by hand with a Silicon Carbide sharpening stone. It takes time, but is possible, I did it several times.
Motor speed control for small 120V. AC. fans? - Forum for …
Jul 30, 2004 · 120 vac fan speed controller I have found a very useful, inexpensive, no problem, inductive load, 5 amp, AC fan control for the size motors under discussion. It is a single pole, fully variable rotary speed control from Ace Hardware model 5A-120 AC for ten dollars ($10). It fits inside of a standard electrical box.
How to correctly calculate coil's field strength?
Jun 21, 2019 · The given simple field equation is valid for long solenoids, almost exactly for length >= 100*radius. There's also a simple equation for the field at the centre line of short (radius < length) and a slightly more complicated formula for medium length coils.
Toroid core - Forum for Electronics
Aug 25, 2024 · 1,413. Location. Richmond Hill, ON, Canada. Activity points. 62,314. You compute power in a toroid as you would for any non-linear inductor, and the value assigned is when L reduces by 10% at some temp and rms current level. This current level guarantees non-saturation if the temperature is allowed to stabilize.