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This is an old revision of this page, as edited by 24.85.131.247 (talk) at 15:36, 1 August 2013 (→‎DC Tape Bias: new section). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

DC = Direct Current, DCT = Discrete Cosine Transform.. the reference suggests a link stronger than that which exists.

Analogy

Far as I know, it wasn't an analogy but an original purpose. Around 1950 when engineers invented digital line codes they got help from mathematicians, who later applied the math answers to other fields. I don't mind the math folks running off with a useful idea, but they shouldn't steal its origin as well. Alas, I have no reference for either the analogy theory, or my own. Jim.henderson 23:06, 4 August 2007 (UTC)[reply]

Could anyone clarify the difference between DC bias and DC offset? I know nothing about electronics, but from the articles, they both seemed to be defined as the mean amplitude of a waveform. Google suggests that they are different things, but it's very unclear. It seems like DC offset should at least be mentioned/linked somewhere in this article (the offset article just has DC coefficient linked under "See Also" without any explanation). Propaniac (talk) 15:40, 25 August 2008 (UTC)[reply]

DC offset is a property of a waveform, an abstract mathematical concept, while DC bias is a property of an electrical circuit, a concrete physical property. Less rigourously, DC offset is generally something you want to eliminate or at least ignore, while DC bias is generally something you need to add in order for a circuit to work properly. The current articles reflect this difference, although I'm sure it could be made clearer (and perhaps given citations). I would oppose the proposed merger. Tevildo (talk) 18:10, 18 October 2009 (UTC)[reply]
Thinking about this in more detail, I would propose that we move the non-electrical meanings of the term from DC bias to DC offset (including the redirects from DC component and DC coefficient). "Bias" is the concrete as opposed to the abstract meaning. Tevildo (talk) 18:21, 18 October 2009 (UTC)[reply]

Circular Statement

The following statement is circular: "DC-balanced waveforms are useful in communications systems, since they can be used on AC-coupled electrical connections to avoid voltage imbalance problems between connected systems or components." It is essentially saying that DC-balanced waveforms are useful because they avoid voltage imbalance, which is obvious from the term "DC-balanced" itself. The article does not say why DC-balance is important: i.e.: what the consequences are of voltage imbalance in an AC-coupled circuit. These problems include bit errors when a (relatively) long series of 1's create a DC level that charges the capacitor of the high-pass filter used as the AC coupler, bringing the signal input down to a 0-level. I have added this sentence and invite anyone to re-write it more elegantly.--Jelsova (talk) 21:59, 1 October 2008 (UTC)[reply]

DC Tape Bias

I do not believe that a DC tape bias was ever used for reducing distortion. It might have been used by accident. Does anyone have a reference for this claim? DC offset in the recording head can only increase distortion, by lowering how much headroom there is before the core saturates. 24.85.131.247 (talk) 15:36, 1 August 2013 (UTC)[reply]