I recall reading somewhere that putting DC current through wire turns on ferrite toroids could result in damage to the material. Am I recalling correctly? Is there a current threshold that should be
Jeff, Some ferrite materials are design to change permeability with DC bias, sometimes by as much as a factor of ten. I'm not sure if all mixes will do this or only those specifically designed to do
Charles: I'm not sure that this has an application for Beverage matching, but I have made use of the variable permeabilty property in remotely tuning a loop antenna. This is done by controlling dc i
You have two very good reasons NOT to worry. First, the toroids see only the DIFFERENCE between the current on the shield and the current in the center conductor, which is zero. Second, the current i
For almost any imaginable ham application of ferrites, we want the core to operate in its linear region. Especially with smaller cores, DC bias currents through any windings can be a real concern. En
YES! And a LARGE core running near saturation could also introduce distortion -- that is, INTERMOD! This could be a VERY big deal in a voltage balun, because the core carries the entire output of the
That's all very true but it is imporant to point out heating does not mean saturation. As a matter of fact one of the most common myths about cores is heat = saturation. That's just wrong. While the
This is scary! How do you know if you are exposed to such trouble?I think in my small property it would be unlikly to develope such a problem but with somebody close to a power sub station or heavy i
A clamp on current meter with low frequency response. I have two types here (for very low frequencies) an "Amprobe" for power lines and a homebrew hall cell detector. You'd also be surprised how muc