Decibel Meter - The circuit below responds to sound pressure levels from about 60 to 70 dB. The sound is picked up by an 8 ohm speaker, amplified by a transistor stage and one LM324 op-amp section. You can also use a dynamic microphone but I found the speaker was more sensitive. The remaining 3 sections of the LM324 quad op-amp are used as __ Designed by Bill Bowden
Half-flying capacitor analog multiplexer for microControllers - This technique uses digital I/O pins to multiplex analog voltages into an analog input on the microcontroller. The method is most suitable for signals that do not need to be sampled frequently and it may be extended to accommodate a large number of inputs, though for a large number of inputs, the use of a separate analog multiplexer or a mincrocontroller with an integrated multiplexer would often be a better choice __ Designed by Dick Cappels
LED Decibel Meter - The circuit below responds to sound pressure levels from about 60 to 70 dB. The sound is picked up by an 8 ohm speaker, amplified by a transistor stage and one LM324 op-amp section. You can also use a dynamic microphone but I found the speaker was more sensitive. The remaining 3 sections of the LM324 quad op-amp are used as __ Designed by Bill Bowden
Rectifier tracks positive & negative peaks - 06/08/06 EDN-Design Ideas Versatile precision rectifier also delivers full-wave output Design by Harry Bissell Jr
Simple Circuit 3 Transistor Audio Amp 50 Milliwatt - Here is a little audio Amplifier similar to what you might find in a small transistor radio __ Designed by Bill Bowden
Single Pulse Voltage Multiplier - Sometimes it's necessary to generate a higher voltage pulse from logic circuits than the circuits themselves can supply. The need to generate a programming pulse for Atmel flash controllers was one of those. In that case, I needed to generate an infrequent pulse that __ Designed by Dick Cappels
Temperature controller has "take-back-half" convergence algorithm - 09/15/05 EDN-Design Ideas Enhanced closed-loop control balances stability, responsiveness Design by W Stephen Woodward, University of North Carolina, Chapel Hill, NC
Two Quadrant Analog Multiplier uses No Log Amps - 10/10/96 EDN-Design Ideas You usually obtain product of two values by summing outputs of logarithmic amplifiers. block diagram in Figure 1 shows a configuration that produces a two-quadrant product of analog signals but uses no log amplifiers. VA and VB are multiplier inputs. triangle generator produces a linear triangle whose voltage range is between0V and maximum value that VB can attain (VB>=0V]. VA may assume both positive and negative values. Figure 2 shows circuit waveforms Design by Giovanni Romeo, Istituto Nazionale di Geofisica, Rome, Italy
Two-quadrant multiplying DAC utilizes octal CMOS
buffer - 09/30/13 EDN-Design Ideas Here's a novel approach to making a multiplying DAC Design by Ajoy Raman |