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TB056: Demonstrating the *set_report* Request: With PS/2® to USB Keyboard
Translator Example - Microchip Application Note Published 4-May-04
(app note added 2/06) |
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Telephone Hold Button (Aaron Cake) - Although a hold feature is
standard on most new phones, a lot of us still use the origional bell
phones. Those of us that require a hold feature will find this circuit very
useful. It is easy to build, and is compact enough to be installed inside
the phone with no real problem. It is also powered by the phone line itself,
eliminating the need for batteries.... [Circuit Design by Aaron Cake] |
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Temperature Controlled Relay Circuits - The first circuit
energizes the relay when the temperature rises above the preset level. The
second circuit energizes the relay when the temperature falls below the
preset level. The two circuits are practically identical. The only
difference between them is the polarity of the transistor. The value of the
thermistor is not critical. The important thing is the voltage on pins 5 &
6. Any value thermistor should work satisfactorily. But you may need to
change the value of R1 - to achieve the desired range of adjustment.
(Circuit designed by Ron J added 09/09/09) [Circuit Design by Ron J.] |
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Test System Signal Switching - Agilent Application Note (added 6/06)
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The Behavior of CMOS in hot insertion - Pericom Semiconductor Application
Brief # 039....[App Note] |
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Thermal switches provide circuit disconnect - 4-Sep-03 Issue of EDN A
single temperature sensor can provide an interrupt to a microcontroller when the
measured temperature goes out of range. You need multiple temperature sensors when you
have to monitorthan one hot spot. A microcontroller implements the proper protective
action when one of the temperature monitors detects an overtemperature condition....
[Design Idea by Mark Cherry, Maxim Integrated Products, Sunnyvale, CA] |
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Thermostat With Adjustable Hysteresis - This small thermostat allows you to
select the size of its hysteresis. You can set both the temperature at which the relay
will energize, and the temperature at which the relay will de-energize. The difference
between these two temperatures is the hysteresis.... [Circuit Design by Ron J.] |
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Three parts provide tenfold increase in switcher current - 22-Aug-02 Issue
of EDN Industrial-control circuits often derive their power from widely varying
sources that can exceed the 40V maximum rating of popular switching ICs. This
Design Idea presents a simple, flexible, and inexpensive buck switcher that converts
an input voltage as high as 60V to 5V at several amps. The circuit is unique in that
it boosts current with almost no compromise in performance, size, or cost.... [Design
Idea by Wayne Rewinkel, National Semiconductor, Sunnyvale, CA] |
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Three-state switch interface uses one microcontroller pin - 21-Feb-08 Issue
of EDN A single microcontroller I/O pin senses the state of a three-position
switch.... [Design Idea by Kartik Joshi, Netaji Subhas Institute of Technology, New
Delhi, India] |
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Through Glass Push Button Switch - This simple technique allows a mechanical
pushbutton switch assembly to activate a reed type relay through a pane of thick
glass. Pushing the button moves a magnet near the reed relay, closing the relay
contacts. …. [Designed by David A. Johnson] |
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Throughput Expansion with FET Based Crossbar Switching - Pericom
Semiconductor Application Note # 045....[App Note] |
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Timer light switch-Digital - Typical circuit representative of those used in
most light switch type digital timers. The timer module is normally a PIC or custom
chip, and it syncs to the AC line so that a trigger pulse can be supplied at the right
moment….schematic only…. [Circuit by Stepan Novotill] |
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Tiny RGB Video Multiplexer Switches Pixels at 100MHz - DN205 Design
Notes (Linear Technology) (app note added 6/06) |
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Toggle Switch Control Of Twin Coil Switch Machines - These circuits allow an
ON-ON type DPDT toggle switch to control a twin coil switch machine motor. The handle
of switch can then be used to indicate the route selected. The circuits are also able
to control LEDs that could be used to indicate the selected route. [from Rob Paisley's
Model Train web site] |
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Toggle Switch Debounced Pushbutton |
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Toggle Switch No. 1 - This simple circuit will energize and de-energize a
relay at the push of a button. Any type of momentary action push-to-make switch can be
used. Pushing the button once - will energize the relay. And pushing it a second time
- will de-energize the relay....(Circuit designed by Ron J added 09/09/09)
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Toggle Switch No. 2 - Pushing the button once will energize the relay.
Pushing the same button a second time will de-energize the relay. Any simple momentary
action push-to-make switch will do…. [Ron J.'s circuit] |
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Toggle Switch No.1 - This simple circuit will energize and de-energize a
relay at the push of a button. Any type of momentary action push-to-make switch can be
used. Pushing the button once - will energize the relay. And pushing it a second time
- will de-energize the relay.... [Ron J.'s circuit] |
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Toggle Switch Number 3 - This versatile circuit provides a selection of
different switching modes. It can be used as two entirely separate toggle switches -
with each push button successively energizing and de-energizing its own relay. Or the
two switches can be interlinked with diodes - to produce a number of different
switching patterns. For example - the circuit can be used to reverse the direction of
DC motors.... [Ron J.'s circuit] |
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Touch Activated Alarm - Not much to tell here as the circuit speaks for
itself. The 555 can be almost any type, they are all pin-compatible. Although some
CMOS types may not have enough power to drive the transistor, in that case use an
ordinary 555. C1's working voltage should be increased to 25V if you decide to go with
a 12V power source. Change the value of C1 for the desired output pulse.... [Tony van
Roon's circuit] |
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Touch Dimmer - .... |
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Touch Keypad - This board layout was created using the SOIC version of a
PIC16F627A without drawing the usual schematic first. Most of the part values
are etched on the Layout. The SIP resistor packs I used are 10k ohm, some
experimentation with this value may be useful....(circuit added 08/08/08) [Luhan Monat
- Mesa Arizona] |
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Touch Switch - This circuit uses a 555 timer as the bases of the touch
switch. You can learn more about 555 timers in the Learning section on my site. When
the plate is touched the 555 timer is triggered and the output on pin 3 goes high
turning on the LED and the buzzer for a certain period of time…. [Randy Linscott's
design] |
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Touch Switch - The Touch Switch circuit will detect stray voltages produced
by mains voltages and electrostatic build-up in a room. In the first circuit, pin 2
must see a LOW for the circuit to activate. If sufficient static voltage is
detected by the plate, the chip will change state. If not, you will need to touch the
plate and the 0v rail.... |
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Touch Switch - A touch switch is a switch that is turned on and off by
touching a wire contact, instead of flicking a lever like a regular switch. Touch
switches have no mechanical parts to wear out, so they last a lot longer than regular
switches. Touch switches can be used in places where regular switches would not last,
such as wet or very dusty areas.... [Aaron Cake's design] |
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Touch Switch Circuits - All the circuits and projects we describe in these
articles consist of very important "building blocks" that you can add to other
designs. This time we describe the concept of touching a plate (or two plates
separated by a small gap) and turning a circuit ON or OFF. A TOUCH PLATE is classified
as a high impedance device....(electronic designs added 08/08/08) |
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Touch switch needs no DC return path - 3-Feb-05 Issue of EDN Common
designs for touch switches detect a decrease in resistance when a user's fingertip
either connects a contact to the circuit's common ground or supplies an injection of
60-Hz ac voltage, resulting from immersion in the electrostatic field that nearby
power lines radiate. But what if no nearby power lines exist and the equipment
operates from a battery source, such as in an automotive appl.... [Design Idea by Brad
Albing, Philips Medical Systems Inc, Cleveland, OH] |
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Touch Switch using Transistors - Schematic & notes only there no circuit
description…. [Tony van Roon's circuit] |
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Touch Switches - (electronic circuit added 1/03) |
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Touch-activated timer switch extends battery life - 10-Jul-08 Issue of EDN
Designed to fit into the battery compartment of an optical mouse, this circuit
automatically shuts off the battery after a time delay.... [Design Idea by Israel
Schleicher, Prescott Valley, AZ] |
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Transformer Driver Controls BiDirectional Switch - 07/17/97 EDN-Design
Ideas....You can use a transformer-driver IC to simply control a MOSFET on/off
switch.... EDN is migrating links. This link is not verified. Search the "title"
+ "EDN" for new link. |
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Translating DVD Video with Pericom's PI5C3245 & PI5C16212 Bus Switches -
Pericom Semiconductor Application Brief # 012....[App Note] |
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Travel Touch Alarm - The Travel Touch Alarm can be used to provide a audible
alarm when someone touches the door knob or handle of your hotel room. The door
knob or handle must be made of metal for the circuit to work. The main chip in the
circuit is a 555 timer…. [Circuit design by Randy Linscott] |
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TRIAC Light Controller - This project is intended for controlling mains
powered disco lighting, although there are many other possible uses for controlling
almost any mains appliance. It will control five seperate channels at up to 3 Amp per
channel. This could be increased by designing another PCB with wider tracks than
the PCB included with this design.... [Matthew Hewson's circuit] |
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Triac lighting and heating controller uses few parts |
| - 2-Sep-04 Issue of EDN The
triac lighting-control circuit in Figure 1 is small and inexpensive because load and
housekeeping power come directly from the line voltage, thereby eliminating bulky,
expensive supplies. The CLZD010 closed-loop controller maintains constant light
intensity by automatically adjusting the timing of the triac's firing until the
feedback signal and setpoint command are equal.... [Design Idea by David Caldwell,
Flextek Electronics, Carlsbad, CA] |
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Turn on the aquarium lights every day at the same time - Turn on the
sprinkler or the aquarium lighting for the same period of the day. You can choose to
operate the output by every 2nd, 3rd day only. There is a manual start/stop button to
immediately turn on or off the output, and a disable button to completely turn off
automatic operation.... [Peter Jakab, Electrical Engineer, Engineer of Informatics] |
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Two Buttons Provide Safe Start - 07/06/00 EDN-Design Ideas....The circuit in
Figure 1 provides a safety interlock that checks the actuation of two pushbuttons
before enabling a relay. When you push both buttons, the circuit actuates the relay.
At that point, you can release one of the switches without the relay'.... [Design Idea
by Vincent Himpe, Alcatel Microelectronics, Desselgem, BelgiumVincent Himpe, Alcatel
Microelectronics, Desselgem, Belgium] |
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Two Light Controlled Relays - These two circuits use LDRs (Light Dependent
Resistors). Circuit No.1 energizes the relay when the light rises above a preset
level. Use it to switch things on at dawn. Circuit No.2 energizes the relay when the
light falls below a preset level. Use it to switch things on at dusk. [Circuit
designed by Ron J.] |
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Two Line Intercom Plus a Telephone Changeover Switch - The circuit presented
here can be used for connecting two telephones in parallel and also as a 2-line
intercom. Usually a single telephone is connected to a telephone line. If another
telephone is required at some distance, a parallel line is taken for connecting the
other telephone. In this simple parallel line operation, the main problem is
loss....(added 5/02) |
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Two Temperature Controlled Relays - These two circuits use Thermistors
(Temperature Dependent Resistors). Circuit No.1 energizes the relay when the
temperature rises above a preset level. Use it to switch things on when it gets hot.
Circuit No.2 energizes the relay when the temperature falls below a preset level. Use
it to switch things on when it gets cold. [Ron J.] |
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Two-wire, four-by-four-key keyboard interface saves - 08/17/06 EDN-Design
Ideas....You can use a microcontroller that includes an ADC to design a
two-wire-plusground keyboard interface. For example, you can use a resistive voltage
divider to identify a pressed key (Reference 1). A microcontroller’s integrated ADC
typicallyou can use a microcontroller that includes an ADC to design a
two-wire-plusground keyboard interface. For example, you can use a resistive voltage
divider to identify a pressed key (Reference 1). A microcontroller’s integrated ADC
typically.... [Design Idea by Stefano Salvatori, University of Rome, Rome, Italy; and
Gabriele Di Nucci, EngSistemi, Rome, Italy] |
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Typical Application For The UPG2150T5L Switch - Application Note California
Eastern Laboratories Doc #962....[App Note] |
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Ultra Low Voltage N-Channel Analog Switch Transmission Gate - Circuit Ideas
for Designers Application Notes Advanced Linear Devices, Inc....[App Note]
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Ultrasonic Switch (Andrew Wilson) - The circuit described generates
(transmits) ultrasonic sound of frequency between 40 and 50 kHz. As with any other
remote control system this cirucit comprises of a mini transmitter and a receiver
circuit. Transmitter generates ultrasonic sound and the receiver senses ultrasonic
sound from the transmitter and switches on a relay....(electronic circuit added 4/05)
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Undershoot Protection When using Bus Switches - Pericom Semiconductor
Application Note # 030....[App Note] |
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Universal 4 Digit Keypad Operated Switch - I've modified the design of the
output section - to free up the relay contacts. This allows the circuit to
operate as a general-purpose switch. I used a SPCO/SPDT relay - but you can use a
multi-pole relay if it suits your application....(Circuit designed by Ron J added
09/09/09) |
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Universal Telephone Hold - Place any phone in your house on holdeven
cordless phones. 7 pages. Not available as a kit of parts. [free circuit from
Golab.com] |
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USB Printer Sharing Switch - I had two computers, a Mac Mini and a generic
Windows computer. Both were on different networks, but in the same room, and I wanted
to share a Lexmark USB laser printer between the two of them. I ended up making this
switch to share the printer between the two computers....(schematic / circuit added
6/07) |
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USB switch - You can connect one USB device like a printer or scanner on 2
computers and controlled by software.….(electronic schematic added 03/09) |
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Using model PSW-1211 as a SPST switch - AN-80-001 Application Note
MiniCircuits.com (app note added 08/08/08) |
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Using the RSW-2-25P switch - AN-80-004 Application Note
MiniCircuits.com (app note added 08/08/08) |
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VGA Switch - Digital VGA switch for switching between two PC monitors with
MAX465 IC..... |
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Video Routers - VISW 8 x4 Stereo audio/video router (added 5/02)
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Video Switcher - Monitoring several cameras on one monitor is usually done
in one of two ways: divide the screen into sections and show them all at once, or time
sequence the cameras onto the whole screen. This device uses the second method
(which, if you don't already know,….(electronic schematic added 08/08) [Luhan Monat -
Mesa Arizona] |
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Video Switcher - Automatically or manually switch the outputs from up to
four cameras into one video monitor. 8 pages. Not available as a kit of parts. [free
circuit from Golab.com] |
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Voice activated switch - The VS-1 provides quality components and a compact
printed circuit board that makes it a snap to “turn on” a multitude of devices, from
HAM transmitters and amps to tape recorders or clandestine listening equipment....HAVE
FUN!....(electronic design added 6/07) |
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Voice over Circuit - switches automatically from sound source to
microph1-when enough sound comes in from microph1(added 5/02) |
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Voltage Comparator Switch - This circuit will provide an indication whenever
the input voltage differs from two defined limits, V1 and V2. The supply voltage, Vcc
must be higher than the highest input voltage by at least 2 volts. One application
here is to monitor a 12V car battery....(electronic schematic / circuit added 4/02)
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Voltage Controlled Switch using 555 - In this circuit the 555 timer is used
in a novel way, as a voltage controlled switch….(Circuit designed by Miroslav Adzic
added 6/07) |
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Voltage-Based Controller for Switches - (circuit / schematic design added
6/06) |
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Vxi Switching Application Note 5968-7234 - Aligent Application Note
(app note added 04/05/06) |
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Water Activated Relay (Marin Lukas) - In his circuit Marin has used two
transistors wired as a high gain compound pair. Transistor T1 may be a 2N2222A and T2
a BC108. The current gain will be the product of each transistors beta, which will be
a minimum of 140 x 110 or 15400. The power supply used can be any voltage from 4.5 to
15 volts,.... [Designer is Marin Lukas] |
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Waterproof Bathroom Switch - The object of this circuit is turn the domestic
lighting on and off in complete safety in a room with very high humidity. A detector,
flush-mounted into the wall, detects the magnetic field variations ….must register on
this site.... [Published in Elecktor July/August 2010] |
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Whistle on Whistle Off - This CMOS toggle flip flop circuit has an addition
of2bandpass filters and condenser microphone so the relay can be toggled by whistling
at it…. [Bill Bowden's website] |
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Whistle Responder - Beeps when hears your whistle A gadget suitable for
key-holders, games etc..... |
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Whistle Switch - (electronic schematic / circuit added 4/02) |
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Whistler: Electronic Trainer/Coach - This device makes it possible to
generate beeps at chosen regular time intervals for timing track race training. Each
time interval is indicated by a beep, and the end of a performance test is indicated
by a double beep. Two types of test are allowed.….must register on this site....
[Published in Elecktor July/August 2010] |
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White LED driver backlights LCD and keypad - 13-Nov-03 Issue of EDN
Designers widely use white LEDs to backlight color LCDs and keypads in handheld
devices, such as cell phones, MP3 players, GPS navigators, and PDAs. Their spectrum
and brightness represent near-ideal light sources. One possible configuration for a
phone or a phone/PDA combination is to have a group of three LEDs to light the display
and six LEDs for the keypad.... [Design Idea by Fabien Franc, Catalyst Semiconductor,
Sunnyvale, CA] |
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XY Keypad uses µC's Serial Port - 10/10/96 EDN-Design Ideas....Interfacing
an X-Y keypad to a microcontroller usually uses a parallel port of 8 bits or more. But
with the circuit shown in Figure 1, a more efficient interface using a
microcontroller's serial port reduces the number of connections required from eight to
three. This interface uses the MM74C922N, a National Semiconductor keypad
encoder,.... [Design Idea by James Mears, National Semiconductor, Tacoma, WA] |
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Zero-Delay Bus Switches - Pericom Semiconductor Application Note #
001....[App Note] |
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