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Title: Public address amplifier Post by: corbo on August 15, 2008, 10:04:08 22:04 Hello !!!
I try to make an public address amplifier . The output of the amplifier is generally fed to a transformer that has a secondary winding arranged to produce 100 volts at full output. Can be used an usual amplifier and an external step-up transformer ? How can be calculated this transformer (number of turns etc. ) .Can be used ferrite core ? Or maybe somebody have an schematic of an transformerless public address amplifier. Which is the best choice ?? Thank you !!! Title: Re: Public address amplifier Post by: Walkura on August 16, 2008, 01:38:56 13:38 The transformer is from what i remember only there te reduce cable losses .
In this matter i would really wonder do you really need that . I worked in a theater we had space for 500 people near the stage + 500 elsewhere . We never used an 100 Volt system . Unless you really have football stadium big places to provide with loudspeaker cables i wouldnt mind the transformer . Ferrite isn't usefull for this transformer . You really need a iron core for this . For as far my memory serves me audio transformers are just like voltage transformers but then they transform resistance (except some winding differences ). R1>R2 = N1>N2 (sorry for not being able to provide the correct formula's ,school is 20+ years ago :) |