Convention Paper
A Microprocessor Based TEF Analyzer
AES Convention 72 · Paper 1946 · October 1982
Abstract
A series of computer programs for AC CIRCUIT ANALYSIS and OPTIMIZATION and MEASUREMENTS will be explained. The ANALYSIS program plots graphs for GAIN, PHASE, PHASE DELAY, GROUP DELAY, SQUARE WAVE response, IMPULSE response, STEP response, or OUTPUT WAVEFORM for any stimulus waveform, IMPEDANCE magnitude (ohms), and IMPEDANCE PHASE (degrees), given the schematic diagram in RESISTORS, CAPACITORS, INDUCTORS, and CURRENT CONTROLLED CURRENT SOURCES, which can characterize transistors or OPAMPS. This type of analysis is useful for passive and active filters and studies of opamp feedback circuits for closed loop gain and stability. OPTIMIZATION is a powerful addition which tweaks the circuit component values to achieve a target response for transfer functions or impedances. Examples will be shown for creating active filter circuits which can exhibit a 4 pole filter with only 1 opamp. The MEASUREMENT program is used to digitize a square wave stimulus and output waveform of the device under test for FFT and DECONVOLUTION calculations to reveal magnitude and PHASE graphs of audio tape recorders both analogue and digital. The programs run on Hewlett-Packard Desktop Computers 9845, 9826, 9836, 87, and 86.
