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	Robot Room - Photoresistor Grab Bag
		Another five photoresistors were partially shorted (or otherwise defective) such that their values were less than 4 kilohms for both brightness and darkness.
		Although not counted as defective, of all of the Jameco huge photoresistors, a few were stained, many had bent leads (the leads are very thick), and many leads had some residual gunk on them indicating they were used.
		One photoresistor was permanently shorted (0 ohm) and another was permanently open (infinite resistance).
	www.robotroom.com /PhotocellGrabBag.html (807 words)

	How to Build a Robot Tutorial - Society of Robots
		Photoresistors (also often called phototransistors or CdS photoconductive photocells; use 'photocell' for digikey) are simple resistors that altar resistance depending on the amount of light place over them.
		Photoresistors are probably the most common, the most affordable ($1-$2 each), and the easiest of all robot sensors to implement.
		Unless you are one of the.00001% of the world population that has a third arm, you should really get one of these alligator clip holder things.
	www.societyofrobots.com /schematics_photoresistor.shtml (953 words)

	One Day Computer Interface Workshop -- Photoresistors (Site not responding. Last check: )
		Photoresistors are light sensitive resistors whose resistance decreases with the amount of light falling on them.
		To pick the resistor, you need to realize that this circuit is just a generalization of the basic building block of analog electronics, the voltage divider.
		Use an ohmmeter to measure the resistance range of your photoresistor for your range of light intensities.
	web.mit.edu /rec/www/workshop/photoresistors.html (153 words)

	Using photoresistor array in robotic applications
		This is because if the photoresistors resistance is say 1k at 'average' light, 1k resistor should be used (to make voltage divider, and to assure that average light will be converted as 128 by 8-bit A/D converter).
		Because of this, photoresistors on inputs 2,3 and 4 aren't affecting other resistors.
		Some of the improvements I can think of are: using photodiodes instead of photoresistors (photodiodes that have different characteristics, for colors), using surface mount photoresistors to get 'high' resolution (if exist), using two sided PCB, and placing photoresistors on one and resistors on other side etc. Write me if you make any improvements or whatever...
	www.seattlerobotics.org /encoder/jun99/dusan.html (544 words)

	Photoresistor - Wikipedia, the free encyclopedia
		A photoresistor is an electronic component whose resistance decreases with increasing incident light intensity.
		A photoresistor is made of a high-resistance semiconductor.
		On the right is part of a night light that used a photoresistor to turn on a light in the dark.
	en.wikipedia.org /wiki/Photoresistor (375 words)

	Meter monitor apparatus
		The photoresistor is mounted in a corresponding barrel located in the opposite slot of the guard, with the light receiver barrel opening located to the opposite side of the tube in accurate alignment with the transmitter barrel.
		The output of the photoresistor 38 is connected to form a voltage dividing network to actuate a solid state switching circuit in response to change in the status of the light beam transmission by the pointer 16 as follows.
		The voltage at the sensing node 50 is proportional to the resistance of the photoresistor 38.
	www.nmbest.biz /scitechcatalog/meter_monitor.html (4103 words)

	Robotics Help from Pololu: A Breakbeam Sensor
		The photoresistor acts almost like a switch: when the light is detected, it is closed, connecting the output directly to ground.
		A very common use is as a odometer - the LED and photoresistor sit on opposite sides of a wheel that turns as your robot drives.
		Connect longer wires to your LED and photoresistor, select an appropriate pull-up resistor, and assemble the circuit according to the diagram.
	www.pololu.com /advice/examples/breakbeam (649 words)

	Process for producing a photoelectric detector of the high-sensitivity photoresistor type - Patent 4652335
		In a photoresistor, the electricity-conducting mechanisms are such that there may be a gain G whose value is given by the ratio between the life time.tau..sub.v of the photo-created carriers and their transit time.tau..sub.t to cover the interelectrode distance (the electrodes necessary for making contacts define this distance): ##EQU1##
		It is a particular object of the invention to define a process for increasing the sensitivity of a photoresistor of the type in question by increasing the natural surface potential of the gallium arsenide (GaAs) which constitutes the active layer thereof.
		The variations in the obscurity current as a function of the voltage applied to terminals 5 of the photoresistor follow curve A in the absence of channel 6 and curve B in the presence of this channel.
	www.freepatentsonline.com /4652335.html (2198 words)

	Matrix encoder for sensor arrays - Patent 4536762
		The unscanned photoresistors of the column are connected between the column conductor and a separate terminal of the microcomputer held at ground potential.
		In order for the photoresistors to provide a reliable indication of the angular positions of the code wheels, it was therefore necessary to exercise considerable care in the construction of the arrays and in the selection of arrays to actually be used, to thus insure very tight tolerances on the array electrical parameters.
		The selected photoresistor is thus being "referenced" to the parallel combination of the remaining column elements, in which the reference is an average of the characteristics of the remaining photoresistors in the column.
	www.freepatentsonline.com /4536762.html (5422 words)

	Safety device for electrical apparatus containing a dielectric gas, in particular circuit breakers or voltage-droppers ...
		4 shows an embodiment in which a photodetector such as a photoresistor 30 is connected to a gate circuit 27A associated with a battery 28 and serves to feed a small solenoid 31 whose core 32 constitutes a retaining abutment for a flyweight striker 33 under thrust from a spring 34.
		In another variant, the photoresistor is replaced by a photodiode likewise associated with a power supply and a gate circuit including time delay means and controlling a striker or a solenoid.
		In a variant embodiment, the means for opening a passage for the gas inside the enclosure in the event of a long-duration arc, is an explosive charge which is fired under control of a detonator having time delay means and itself tripped by the photo-generator.
	www.freepatentsonline.com /5089931.html (1860 words)

	Overview
		Photoresistors change resistance based on the amount of light detected, but the Cerebellum can only read in voltage.
		In this circuit, the photoresistor is attached to the 5 Volt Cerebellum power source, and to the 4.7k resistor.
		On the other hand, when the photoresistor has an ultrabright LED pointed directly at it, the resistance is closer to 500 Ohms, so Vout is almost 5V.
	www.andrew.cmu.edu /user/sshamlia/98012/S05/photovore/photovore.htm (303 words)

	EE-210, Lab 6, Op-Amps, Part Deux
		A photoresistor is a resistor that is sensitive to light.
		The photoresistor you will use has a resistance of about 2.5 kohms in the dark, and 380 ohms in bright room light.
		A photoresistor is a class of resistors referred to as negative coefficient resistors.
	people.msoe.edu /~barnicks/courses/EE-210/EE-210_Spring_2004_lab6.htm (524 words)

	photoresistor data sheet
		Photoresistor data sheet recommendations (e.g., strong evidence photoresistor data sheet effectiveness photoresistor data sheet to an photoresistor data sheet being strongly photoresistor data sheet and sufficient evidence corresponds to an intervention being recommended).
		Of photoresistor data sheet 243 studies, 77 were excluded on the basis of limitations in their.
		Photoresistor data sheet the extent to which the interventions photoresistor data sheet practiced photoresistor data sheet the photoresistor data sheet States.
	hometown.aol.com /vaha016/photoresistor-data-sheet.html (355 words)

	Photoresistor - Encyclopedia, History, Geography and Biography
		It can also be referred to as a light-dependent resistor (LDR), photocell, or photoconductor.
		This page was last modified 14:18, 29 April 2006.
		Photoresistor, Cadmium sulfide cells, Applications, Circuit Symbol, See also, Optical devices, Transducers and Detectors.
	www.arikah.net /encyclopedia/LDR (374 words)

	[No title] (Site not responding. Last check: )
		Before placing the photoresistors to the display bulb, it is necessary to shield the sides of the vacuum tube with two small fl adhesive strips, as shown in Figure 6, so that only a light slot of about 1.5 mm is left.
		The photoresistor resistance Rphr is inversely proportional to the luminous energy E(nu) striking it [3]: therefore, we have: The current Ia emitted by the vacuum diode filament, if stable, does not affect the operating of the instrument at all, therefore, it can be used to perform the periodic calibrations of same.
		Periodic calibrations are necessary to define the K constant of the instrument defined as the relative variation (or percentage) of the anode current Ia, per unit variation of the potential difference VCD at the ends of the bridge [4].
	www.rhfweb.com /gravdetect.htm (3195 words)

	Welcome to Adobe GoLive 6
		The photoresistor is part of a resonant circuit (using a 555 timer) that produces a square wave with frequency proportional to the resistance.
		Since the frequency of the square wave input is proportional to the light seen by the sensor, your module should move the servo1 to maximize the frequency of the signal (i.e., minimize the period).
		This code segment measures the number of 0.5 ms ticks in one period of the pulse generated from the photoresistor and writes the angle to which to move the servo into a real-time fifo (you have to compute the angle yourself.) The precise period is unimportant; your control should just try to minimize it.
	www.engr.uky.edu /~ee599/proj3/proj3.html (675 words)

	Silonex Inc. : Audiohm Optocouplers : principles of operation (Site not responding. Last check: )
		The light falling on the photoresistor causes the resistance to reduce, after a period of time (usually ms) the photocell reaches its R"on" resistance.
		When the supply to the LED is removed and the LED stops emitting light, the photoresistor reacts to the removal of the light by starting to return to its "dark" state.
		This is a phenomenon typical of a photoresistor.
	www.silonex.com /audiohm/principles.html (273 words)

	Emergency lighting device - Patent 5336977 (Site not responding. Last check: )
		The solar cell plate (5) is connected electrically to the first terminal of the battery unit (21) so as to absorb solar energy and convert the solar energy into electric energy in order to charge the battery unit (21).
		The photoresistor (71) has a first terminal that is connected electrically to the base terminal of the second transistor (Q2), and a second terminal which is grounded.
		When the resistance of the photoresistor (71) is at a relatively low value due to the presence of strong surrounding light, the voltage across the photoresistor (71) is relatively low when compared to the resistor (R1).
	www.freepatentsonline.com /5336977.html (1950 words)

	Disable Auto Headlamps (Site not responding. Last check: )
		The photoresistor will turn about 1/2 turn, and then drop out of the dashboard.
		I reinserted the photoresistor back into the dash so that the hole would not be empty.
		The photoresistor is essentially a variable resistor whose resistance value changes based upon the amount of light hitting it.
	www.fasidemedia.com /personal/mike/cars/camaross/mods/autoheadlamps/disableautolamps.htm (367 words)

	photoresistor datasheet
		Photoresistor datasheet Interventions were grouped together on the basis photoresistor datasheet photoresistor datasheet similarity.
		Photoresistor datasheet and photoresistor datasheet Second, cigarette-caused fire deaths and second-hand smoke photoresistor datasheet photoresistor datasheet not reflected in the SAMMEC smoking-attributable mortality estimates.
		To select a photoresistor datasheet name and password, photoresistor datasheet photoresistor datasheet Once registered, you will have access to both Adult and MCH photoresistor datasheet photoresistor datasheet you are already registered photoresistor datasheet use SAMMEC, photoresistor datasheet the Adult or MCH SAMMEC photoresistor datasheet or link to login.
	hometown.aol.com /vaha016/photoresistor-datasheet.html (301 words)

	aparrish@itp: pcomp Archives
		This device consists of five photoresistors and a superbright LED strapped to a servomotor, all inside a circular, opaque box.
		The photoresistors are taped to the box's inner wall and the servomotor is secured to the bottom of the box, dead center.
		This value corresponds to how close the current time is to half-past the hour (e.g., at 9:30 the value would be 128, at 10:00 the value would be 0, and at both 9:45 and 10:15 the value would be 64).
	itp.nyu.edu /~ap1607/pcomp (257 words)

	Forklift Report
		The LED's and the photoresistors were placed next to each other in a linear, alternating sequence—the four photoresistors were placed in between each of the five LED's.
		By placing all four photoresistors over the white line it was determined that the sum of the sensor values was approximately 260.
		When the photoresistors were not all over the white line the value of lm was higher.
	www.et.byu.edu /groups/it548/Old_reports/1999_Reports/WoodingsCarlson/line.html (1124 words)

	P2-05.HTML (Site not responding. Last check: )
		DESCRIPTION: A selenium photoresistor is in series with the coil in a relay circuit used to turn a light on and off.
		When the resistance is low the photoresistor passes current which turns on the relay.
		During the daylight, when a streetlight remains on, it is often due to pigeons despoiling the photocell, as illustrated in the photograph at the right above, where a piece of simulated pigeon poop has been positioned on the photocell, blocking the light.
	www.physics.umd.edu /lecdem/services/demos/demosp2/p2-05.htm (157 words)

	[No title] (Site not responding. Last check: )
		Since there is a band gap, we expect that the responses of a photoresistor depend on the wavelength of the radiation.
		Mount the photoresistor at the output of the monochromator.
		Measure and plot the resistance EMBED Equation.3 of the photoresistor as a function of wavelength EMBED Equation.3 from 300 nm to 800 nm.
	www.phy.cuhk.edu.hk /course/2004-2005/phy3822/materials/exp3.doc (659 words)

	Method of forming a plug patent invention
		Thus, the tungsten is widely applied to form the contact plugs or the via plugs in the semiconductor industry so as to electrically connect the former conductive layer with the latter conductive layer, such as electrically connecting a variety of the components with the leading wires.
		As the photoresistor layer gets thinner, corners of the photoresistor layer may be cut or portions of the photoresistor layer may even be etched through before the plug hole etching process finishes.
		The substrate 30 may be a wafer or a silicon-on-insulator (SOI) substrate used in semiconductor industry, and the dielectric layer 32 comprises the dielectric materials, such as silicon oxide which may be formed by a variety of the chemical vapor deposition process or by a way of spin-on process.
	www.freshpatents.com /Method-of-forming-a-plug-dt20060921ptan20060211242.php (2045 words)

	Cadmium sulfoselenide surface-mountable optocoupler page
		A cadmium sulfoselenide photoresistor having an active surface is placed over the substrate with the active surface facing the substrate where the photoresistor has two electrodes.
		A light emitting diode (LED) chip is mounted on the substrate facing the active surface of the photoresistor.
		In an alternative embodiment of the invention, the photoresistor and the LED chip can lie side by side and be in optical communication with each other through a reflective coating on the inside of the cover.
	www.patentalert.com /docs/001/z00169712.shtml (431 words)

	[No title]
		The photoresistor is treated just like a normal resistor in a circuit and follows all the same rules.
		Data and Sample Calculations: The data from the photoresistor and motor are attached as a spreadsheet.
		The photoresistor has a broad range of resistances and is easily incorporated into a voltage divider network.
	www.cs.wright.edu /people/faculty/gpower/daily.doc (1649 words)

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