What is this and what harm can it do to a piece of equipment? Thanks
Alternating current does not have to alternate about 0 volts...when it is shifted by a constant amount, it is said to have a direct current offset. If a DC offset gets coupled to a loud speaker, you could ruin your speaker real fast.
Usually, when you average an AC waveform you get exactly 0V, which means the wave is symmetrical about 0V. There might be some components esp. opamps and amplifiers, which do add a DC-component to the output. Whereas a few millivolts are usually of no concern and normal, an extended amount(Volts) might harm loudspeakers. You can see the diaphragm going off center and staying there, so the excursion is assymmetrical. This causes distortion and heating of the voicecoil. A DC-offset can be blocked with a capacitor.
Dnia czwartek, 19 maja 2005 05:58, we wiadomości DC offset is a average (voltage or current) of some waveform. DC offset causes constant flow of current. It may cause damage for some circuits, because constant current is non-essential in many applications, yet it produces a heat according to Joule-Lenz law. DC offset may also cause a breakdown for transistors gates or diodes (of course it it's to high - above breakdown voltage).