280 Chapter 8
Today’s computer-control systems theoretically offer:
- the remote control of many of most of the facilities and controls considered here
and in other chapters. - the fl exible ganging, nesting, and prioritization of these controls.
- the transmission of real-time signal, thermal, rail voltage, or PSU energy
storage data, monitoring, logging, and alarming. May even include a measure of
utilization, for example, if a particular amplifi er’s swing is largely unused as a
consequence of overspecifi cation. - the remote, even automatic, testing of amplifi ers, speaker loads, and their
connections.
Thus far, most computer-controlled power amplifi ers require an interfacing card to be
plugged in. Some types have integral microprocessors.
A well-designed computer control interface must not affect the analogue systems
grounding or compromise mains safety. These requirements are met by the fi ber-optic,
opto-, or transformer-coupled interfacing, familiar enough in digital audio. Such systems
must also not only meet EMC requirements, but also, in real world conditions, not radiate
or introduce EMI to the power amplifi ers. The system must also be able to recognize
faults in its own connectivity to power amplifi ers.
References .............................................................................................................
- Ball, Greg.M, Overlook THD at your peril, letters, EW WW, August, 1993.
- Cherry, Prof. Edward, Ironing out distortion, EW WW , January 1995.
- Jung, Walt, Audio applications , Section 8 of System Applications Guide, Analog
Devices, 1993. - Penrose , H. E. and Boulding , R. H. S. , Principles and practice of radar , 4th Ed. ,
Newnes , 1953. - Duncan, B., ‘ Black box ’ , HFN/RR , October, 1994.
- Bohm , Dennis , ‘ Practical line driving current requirements ’ , Sound and Video
Contractor , September, 1991. - Duncan, Ben, ‘ AMP-O1 parts 3 and 4 ’ , HFN/RR, July and August, 1984.