Handbook for Sound Engineers

272 Chapter 10 References Inductor and Magnetic Product Terminology, Document No. 34053, March 2002, Vishay Dale. ILB, ILBB Ferr ...

273 Chapter 11 Audio Transformer Basics by Bill Whitlock 11.1 Audio Transformer Basics.......................................... ...

274 11.3.1.2 Balance Characteristics............................................................ 302 11.3.1.3 Resistances, Capac ...

Audio Transformers 275 11.1 Audio Transformer Basics Since the birth of audio electronics, the audio trans- former has played an ...

276 Chapter 11 Therefore, if we place two coils near each other as shown in Fig. 11-4, an ac current in one coil will induce an ...

Audio Transformers 277 (11-3) where, IE is excitation current in amperes, EP is primary voltage in volts, f is frequency in hert ...

278 Chapter 11 The actual transformer is connected at the PRI terminals to the driving voltage source, through its source imped- ...

Audio Transformers 279 flux. As a material saturates, its permeability decreases until, at complete saturation, its permeability ...

280 Chapter 11 to eddy currents. Eddy currents are greatly reduced when the core consists of a stack of thin sheets called lamin ...

Audio Transformers 281 turns of heavier wire is needed for the secondary. Compare this to the total of 240 turns of heavier wire ...

282 Chapter 11 inductance decreases rapidly as the number of layers is increased. 11.1.2.4 Winding Capacitances and Faraday Shie ...

Audio Transformers 283 common-mode noise, or CMRR, as discussed in Chapter 37. In Fig. 11-16, if the primary is driven by a bala ...

284 Chapter 11 tance, were zero, the voltage source—by definition zero impedance—would effectively short out RC, resulting in ze ...

Audio Transformers 285 IM distortion test mixes 60 Hz and 7 kHz signals in a 4:1 amplitude ratio. For virtually all electronic a ...

286 Chapter 11 Except in bi-filar wound types discussed below, leakage inductance LL and load capacitance are the major limiting ...

Audio Transformers 287 output appears as 0.5 Ei in series with RG /4 or 150ȍ. When RL is connected, a simple voltage divider is ...

288 Chapter 11 There is essentially no intrinsic impedance associ- ated with the transformer itself. With no load on its seconda ...

Audio Transformers 289 ments in signal-to-noise ratio are not solely due to this gain. Because most amplifying devices generate ...

290 Chapter 11 design and physical construction very different. Of course, some audio transformer applications need fea- tures o ...

Audio Transformers 291 the primary to evenly distribute capacitances and the incorporation of a Faraday shield between primary a ...