CHAPTER 15 HINTS, TIPS AND HANG-UPS
A simple meter
This is an instructive project aimed at learning something of measurement. Figure 15.1 shows a circuit with a diode, resistor and capacitor. Applying 0 dB tone to the input terminals, and connecting a voltmeter to the output, will give a reading of between 0.75 Vdc and 0.8 Vdc. An oscilloscope will read the same. The programme may confuse a digital voltmeter (DVM), but the oscilloscope should follow the variations in level; experiment with different timebase settings. Note how during periods of silence the voltage falls to zero.
This simple circuit can be turned into a useful piece of kit by building into a box with a moving coil meter connected to the output terminals.
Using headphones ...
Get An Introduction to Video and Audio Measurement, 3rd Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
