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Short Range Reflective Object Sensor - Drawing only 30uA from a 3v
supply, this circuit will detect a human finger with a range of about 1 inch.
The sensor uses an inexpensive infrared LED and a matching photo diode. ….
[Designed by David A. Johnson] |
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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 Activated Lamp - The circuits below light a 20 watt lamp when
the contacts are touched and the skin resistance is about 2 Megs or less. The
circuit on the left uses a power MOSFET which turns on when the voltage
between the source and gate is around 6 volts. The gate of the MOSFET draws no
current so the voltage.... [Bill Bowden's circuit] |
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Touch Dimmer - (electronic Circuit / Schematic added 10/04)
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Touch 'N Flip - Ever wonder how a touch plate, like the kind you see on some
elevators and lamps work?This circuit will give you a feel for how the touch plate works
in a circuit and you can expand on the circuit to suit your project needs. The touch plate
…. [Randy Linscott's design] |
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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 - (circuit added 9/04) |
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Touch triggered alarm - No description available.... [Posted by Jospfh] |
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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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Touch-controlled Dimmer - Here’s a dimmer that, besides being touch-controlled,
also has a setting memory that enables it, for example, to turn the lighting on at the
level you had set last time it was turned off. The project uses a specialized IC, an
LS7534 from LSI Computer Systems, available from Farnell, among others.….must register on
this site... [Published in Elecktor July/August 2010] |
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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] |
