IDEAL Sound Level Meter Macro-Model | My Assignment Tutor

Top Level Design Clarifications – IDEAL Sound Level Meter Macro-Model (PSpice):The IDEAL Sound Level Meter Macro-Model blocks should be replaced by the REAL circuits using, active and passive componentsas well as power supply components. Please note, there are no limitations on power supply or frequency response in theIDEAL system model blocks!General Sound Level Meter Design Parameters:1. You can use the input signals such as 1V; 0.1V; 0.01V; 0.001; 0.0001V (frequency from 10Hz to 20kHz) to cover an inputvoltage loss level range up to 80 dB (but you can also use decades of signal change such as dB/decade). This will provide asensible input voltage as you can then create bode plots using dBV in PSpice. Please note, the maximum AC input voltage of1V corresponds to 0 dB (voltage loss level)!2. The smallest voltage from the microphone is about 6 microvolts. Thus, in order to simulate the circuit using the input values of 1V,0.1V, 0.01V, 0.001V and 0.0001V you need to provide a gain of about 400-1000 for your input filter circuits. Please note, youshould use a stepped attenuator before any gain stage!3. Filter’s circuits should be designed based on the transfer function equations shown in the macro-model. The filter circuitrepresents the frequency weighting conditions which you need to incorporate in your active filter circuits. Each equation representsa pole of the filter of 20.6Hz, 20.6Hz, 12.2kHz, 12.2kHz, 107.7Hz and 737.9Hz respectively. The active filter design should considerthe C- weighting use, to assess the risk of instantaneous human hearing damage, and A- weighting which should takes Cweighting and incorporates the signal parameter in the further active filter. Please note, the AC analysis can be done up to theend of the weighting network, only! After a full-wave rectifier (shown in the above model as the ABS block), this signal isconverted to the r.m.s. through the Squaring, Mean and Square Root blocks, as it gives good correlation with subjective responseto noise. A Log function provides scaling approximately 50mV/dB sensitivity to the peak detector which should achieve at least40dB dynamic range. The output of the peak detector in response to the short input pulse is a step shape signal. Although there willbe a finite rise time of the peak detector output, it will be very short and it is the final peak detector output step signal value that isimportant. The level of this signal depends on the Type of the instrument.


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