|
|
| Line 1: |
Line 1: |
| A '''bridge-tied load''' (BTL), also known as '''bridged transformerless''' and '''bridged mono''', is an output configuration for [[audio amplifier]]s, a form of [[impedance bridging]] used mainly in [[professional audio]] applications.<ref>{{cite book |url=http://books.google.com/books?id=K1t0GxyvVbMC&pg=PA87 |page=87 |title=Guide to Sound Systems for Worship |last=Eiche |first=Jon F. |publisher=Hal Leonard Corporation |year=1990 |isbn=0-7935-0029-X |series=Recording and Audio Technology}}</ref> The two channels of a stereo amplifier are fed the same [[monaural]] [[audio signal]], with one channel's [[electrical polarity]] reversed. A [[loudspeaker]] is connected between the two amplifier outputs, ''bridging'' the output terminals. This can double the voltage swing at the load as compared with the same amplifier used without bridging. The configuration is most often used for [[subwoofer]]s.<ref>{{cite web |url=http://www.directproaudio.com/shop/amplifiers/guide/modes.cfm |title=Stereo, Parallel, and Bridge Mono |work=Amp Guide |publisher=DirectProAudio |accessdate=September 28, 2011}}</ref>
| | The author's title is Christy. For years he's been living in Alaska and he doesn't plan on altering it. To climb is some thing I really enjoy performing. He functions as a bookkeeper.<br><br>Here is my web blog: [http://kjhkkb.net/xe/notice/374835 live psychic reading] |
| | |
| ==Power output==
| |
| | |
| Because the available voltage swing across the load is doubled for the same power supply voltage, bridged output theoretically enables the design of an amplifier producing four times the power output on the same supply voltage, since.
| |
| | |
| :<math>P = \frac{{V^2 }}{R}</math>.
| |
| | |
| However, operating a pair of existing amplifier channels in bridge mode only doubles or triples power output to the load, since the amplifier retains its existing current rating.<ref name=Bartlett>{{cite web |url=http://www.prosoundweb.com/article/print/amplifier_power_master_class_not_all_ratings_are_similar |title=Amplifier Power Master Class: Not All Ratings Are Similar |last=Bartlett |first=Bruce |publisher=ProSoundWeb |date=May 1, 2010 |accessdate=September 28, 2011}}</ref>
| |
| | |
| ==Impedance==
| |
| | |
| Driving the load between two signals of opposite electrical polarity (often incorrectly called antiphase, or 180° out of phase - one signal is ''inverted'', there is no phase change) makes each amplifier see only half the load's [[electrical impedance]]. In practical terms, an eight-ohm loudspeaker could be safely connected to a bridged amplifier that was capable of driving four ohms per channel.<ref>{{cite web |url=http://www.rocketroberts.com/techart/amp.htm |title=Audio Power Amplifier Fundamentals |year=2007 |work=Joe's Tech Notes |last=Roberts |first=Joe |accessdate=September 28, 2011}}</ref>
| |
| | |
| ==Benefits and drawbacks==
| |
| | |
| Since two amplifiers are being used in antiphase, using the same power supply, there is no need for the use of a DC blocking capacitor between the amplifier and the load. This way, it will be more linear and less expensive, use less space, and there is no power loss through the capacitor.<ref>{{cite book |url=http://books.google.com/books?id=Qpmi4ia2nhcC&pg=PA367 |page=367 |title=Audio Power Amplifier Design Handbook |last=Self |first=Douglas |publisher=Focal Press |year=2009 |isbn=0-240-52162-5 |edition=5}}</ref>
| |
| | |
| Bridging an amplifier increases the power that can be supplied to one loudspeaker, but it does not increase the amplifier's total available power. Because a bridge amplifier operates in mono mode, a second identical amplifier is required for stereo operation. For bridged amplifiers, [[damping factor]] is cut in half, so [[speaker cable]]s should have a large diameter conductor or be kept as short as possible for minimum resistance. Because the amplifier's bridged output is floating, it should never be grounded or it may damage the amplifier.<ref name=Bartlett/>
| |
| | |
| ==Uses==
| |
| | |
| This output configuration is useful in applications where battery size dictates a lower supply voltage, e.g., automotive or handheld applications.
| |
| | |
| == See also ==
| |
| * [[Amplifier]]
| |
| * [[Bridged and paralleled amplifiers]]
| |
| * [[Electronic amplifier]]
| |
| * [[Single-ended signalling]]
| |
| | |
| ==References==
| |
| {{reflist}}
| |
| | |
| [[Category:Electronic amplifiers]]
| |
The author's title is Christy. For years he's been living in Alaska and he doesn't plan on altering it. To climb is some thing I really enjoy performing. He functions as a bookkeeper.
Here is my web blog: live psychic reading