220 Volt Live Wire in Wall Scanner:  This circuit will help you to scan  line of a 220V live wire in  wall.  FET gate is connected to a capacitive metal sensor (which is usually a simple metal plate). When you hold  sensor close to  wall,  LED will indicate  current flow around where it detects  wire. Works on 9VDC. (added 6/06)

48 input×16 output crosspoint IC eliminates the need for multiplexer amps:  02/20/03  EDN-Design Ideas / (added 02/05)) Crosspoint switches are ideal for use in video-security systems, which accept multiple camera inputs while providing playback and multiple loop-through to multiple monitors. To provide video loop-through or monitor outputs, se systems often require additional multiplexer amplifiers that can drive standard video loads...

 ADC Multiplexer Expander Works Transparently:  06/20/96 EDN-Design Ideas / (added 6/06)  When you need to multiplex a large number of analog signals into an ADC—as in medical, instrumentation, and or applications—you may find it difficult to find an appropriate ADC that has enough channels to fit your system's needs. You can add external multiplexers, but se normally require additional control lines from  CPU. Also,  time required for switching channels may limit  system's throughput rate. The circuit in Figure 1 allows you to increase  effective size of an ADC's multiplexer without requiring any additional time or control lines from  CPU.

AN-247: Using the ADC0808/ADC0809 8-Bit µP Compatible A/D Converters with 8-Channel Analog Multiplexer:  National Semiconductor Application Note   (app note added 6/06)

AN-249: over Voltage Protection for the ADG5XXA Multiplexer Series:  AN-249 Analog Devices Application Notes  (app note added 6/06)

AN-250: Bandwidth, OFF Isolation and Crosstalk Performance of the AD5XXA Multiplexer Series:  AN-250 Analog Devices Application Notes  (app note added 6/06)

AN-35: Understanding Crosstalk in Analog Multiplexers:  AN-35 Analog Devices Application Notes  (app note added 6/06)

Analog multiplexer uses flying capacitors:  01/22/04 EDN Design Ideas  /  (added 1/05)  This Design Idea describes a way to increase  number of analog inputs to your microcontroller for cases in which adding an analog-multiplexer chip or upgrading to a microcontroller with more inputs might be impractical. If  microcontroller you're using has some spare I/O pins and at least one of m is bidirectional or is amenable to tristating, you can configure a simple analog multiple......

Analog Multiplexers help Test IS IRQs and DrQs:  12/07/95 EDN-Design Ideas / (added 3/03)

Analog multiplier works over large frequency range:  09/16/99 EDN Design Ideas  /  (added 2/06)  

Astable Multivibrator #1:  (electronic (schematic / circuit added 4/02)

Astable Multivibrator #2:  (design added 8/03)

Bandwidth, OFF Isolation and Crosstalk Performance of the AD5XXA Multiplexer Series:  AN-250 Analog Devices Application Notes  (app note added 6/06)

Barcode scanner:  (electronic circuit added 4/05)

Barcode Scanner #2:  Intersil Application Block Diagram  (app note added 6/06)

Data Multiplexer Adds Cursor to LED Display Driver:  03/30/95 EDN-Design Ideas / (added 03/03)

Force/Sense Connection Eliminates Multiplexer on Resistance Error:  01/22/04 EDN Design Ideas  /  (added 1/05)  Digitally controlled gain is an everyday analog-design element. You frequently find this element in an op-amp-based, transimpedance current-to-voltage converter. When you design digital gain control into such a converter, the usual scheme is to arrange things such that a digital multiplexer selects the appropriate feedback resistor for each gain figure....

Garage Door Opener Scanner:  [The opener] uses a 555 timer as a pulse generator to transmit pulses to a binary counter.  Each pulse will increment the binary counter by one.  You can adjust the speed of the counting by turning R1.  Go ahead and experiment to find just the right speed to use.  Switch one is for resetting the count back to the beginning. (added 11/06)

LMH730276 4:1 Multiplexer Evaluation Board:  National Semiconductor Application Note   (app note added 6/06)

LMH730277 2:1 Multiplexer Evaluation Board:  National Semiconductor Application Note   (app note added 6/06)

Low Cost RS-232C Multiplexer Serves as Multiport Adapter:  03/01/96 EDN-Design Ideas / (added 03/03)

LTC1390: A Versatile 8-Channel Multiplexer:  DN112  Design Notes (Linear Technology) (app note added 1/06)

Maximum Voltage Sorter uses Analog Multiplexers:  09/29/94 EDN-Design Ideas / (added 3/03) The voltage-sorting circuit in Fig 1 continuously finds the maximum of eight input voltages and the corresponding binary address with the aid of two analog multiplexers, IC1 and IC2. The circuit compares each input sequentially with the current maximum voltage and updates the maximum voltage and address when it finds a new maximum. IC2 and IC3 act as storage elements. IC4 ensures that latching can't occur at the beginning or the end of a given address, thereby preventing an incorrect address from being latched at an address transition. The sorter can also find the minimum of its input if you swap the CMP01 comparator's input....  

Multiplexer Amplifiers form large multiplane multiplexer structures:  12/26/02 EDN Design Ideas  /  (added 1/05)  The variety of video sources available to a home-video-switching system has grown from a few composite inputs to many multisignal sources. These sources include cable, HDTV, satellite dishes, VCR, DVD, video games in broadcast, and multi-PC or graphic KVM (keyboard-video-mouse) applications. Each requires an N×M-to-1 multiplexer, in which M is the number of sources and N is the number of c......

Multiplexer Creates Mixed Signal Scope Input:  01/16/97 EDN-Design Ideas / (added 08/05) When you work with mixed-signal designs, it's often useful to view the timing of several analog and digital channels on the scope at once. Figure 1 accomplishes this task using two buffered multiplexer ICs and two TTL logic chips. IC1 and IC2 each combine a four-channel multiplexer with an op-amp on the output. The output of the multiplexer connects to the noninverting input of the op amp, and the inverting input is available as an external pin on the IC. This feature allows the multiplexer to have a buffered output and allows each channel to have different gain.

Multiplexer enables pseudomultidrop RS 232 transmission:  09/28/00 EDN Design Ideas /  (added 2/06) 

Multiplexers convert deep FIFO buffer to bidirectional :  12/04/97 EDN-Design Ideas / (added 2/06)  

Multiplying DAC makes Programmable resistor:  06/24/99 EDN-Design Ideas  (added 2/06) 

Over Voltage Protection for the ADG5XXA Multiplexer Series:  AN-249 Analog Devices Application Notes  (app note added 6/06)

PIC Based RS485 Multiplexer:  Recently, I had to design a circuit real quick that transmitted 4 parallel TTL data bits over 350m of twisted pair cable. I needed to feed in four parallel data bits at one end, and get 4 parallel data bits out the other end, completely transparent to the transmitting and receiving circuits.
I decided to implement this using a PIC 16F84 for both an encoder and decoder, and use RS-485 drivers (DS26C31 and DS26C32) to drive the 350m cable. I only needed five I/O pins per PIC, so this could have been implemented....  (added 6/06)

Printer Port Controls Video Multiplexer:  08/01/96 EDN-Design Ideas  /  (added 6/06)

ScanMate Audio Activated Recorded:  your (Radio) scanner buddy! (added 5/02)

Serial Control Multiplexer Expands SPI Chip Selects:  Maxim Application Notes / 210 / Nov-08  (app note added 6/06)

Tiny RGB Video Multiplexer Switches Pixels at 100MHz:  DN205  Design Notes (Linear Technology) (app note added 6/06)

Using the ADC0808/ADC0809 8-Bit µP Compatible A/D Converters with 8-Channel Analog Multiplexer:  National Semiconductor Application Note   (app note added 6/06)

Video multiplexer uses high speed op amps:  08/21/03 EDN Design Ideas  /  (added 1/05)  Video multiplexers route video from several sources to a single channel. Low-end consumer products use CMOS analog switches and multiplexers, such as the 4066 and 4051. Unfortunately, these devices have a series on-resistance that ranges from approximately 100Ω to 1 kΩ, a resistance that is not constant with video level and that appears in series with the signal....

Voltage Regulator controls scanner-lamp brightness:  05/13/99 EDN-Design Ideas / (added 11/06)