On researching the subject, I was surprised that LEDs could be used as light sensors and that there are so many types of sensors for detecting light: photodiodes, solar cells, light dependent resistors (LDRs), and infrared (IR) phototransistors. My curiosity got the better of me and I decided to test them all. I measured the voltage generated by each sensor from different light sources: sunlight, 100 watt incandescent light bulb, IR emitter, and two types of IR remote controls. The IR emitter was connected to 3 AA batteries (4.5 volts) thru a 220 ohm resistor. The light would be brighter if the resistor had a lower value, but I wanted to be cautious after burning an emitter out. The purpose of the tests was to compare different sensors, and not to determine how bright an emitter could shine. Infrared light is invisible to the human eye, but the emitter had a barely visible red glow when lit. LEDs: a pack of 3mm and 5mm LEDs of various colors.The IR light can be seen in the screen of a digital camera. Infrared (IR) detector #2: 5mm (phototransistor), Radio Shack catalog #2760142 contains both a detector and an emitter.Infrared (IR) detector #1: Knight Lites KID-7404 5mm (phototransistor).Light dependent resistor (LDR): 7mm diameter, 300 ohms light resistance and 10M dark.Solar cell: from a very cheap solar garden lamp.Photodiode: BPW34, suitable for visible and near infrared light. Sunlight: not very strong in late December at our latitude of almost 44 degrees North.Comments on the Internet suggest that the detector in some of these packs is a transistor but in other packs it’s a photodiode, even though the description on both packs states “phototransistor” and the catalog number is the same. Digital camera if you want to see whether an IR emitter is working.Breadboard (optional) with jumper wires.LEGO Mindstorms EV3 IR beacon remote control.Infrared (IR) emitter #2: 5mm, Radio Shack catalog #2760142.Infrared (IR) emitter #1: 5mm, Radio Shack catalog #2760143.100 watt frosted, incandescent, 120 volt, light bulb.A quick calculation shows the sun was only about 23 degrees above the horizon at noon. The breadboard is optional, but it makes the job easier and faster. In the photo above, positive 4.5 volts from the battery holder can be supplied to the red row of holes along the length of the breadboard, and the negative side of the batteries to the blue row. The holes in each long row are connected together by metal strips under the board. The various LEDs and light sensors are plugged into different 5-hole rows. The 5 holes in each row are connected underneath. One side of all the resistors is plugged into one 5-row, and the other ends are in different 5-rows. This arrangement allows an LED or light sensor to be connected to any resistor and to power as needed.
#Svat wrc101 series
My first step was to measure the voltage drop across different colors of LEDs, with a variety of series resistors to limit the current. LEDs have a long lead (the anode) which connects to the resistor and then the positive side of the battery, and the short lead (the cathode) goes to the negative side. The cathode may also be identified by a small flat part on the brim of its hat-shaped package. Two photos show the connections for the green LED for one of the tests. An orange jumper is between the anode of the LED and the 5-hole row of the resistors. One photo shows a black wire from the cathode of the LED to the long negative row, and a red jumper from one of the resistors to the red positive row. LIGHT BULB EXPERIMENT RADIOSHARK SERIES.For this reason, getting the best deal for any products will take a little time and effort.Fortunately you visit the right place, we give you the best deal for SVAT WRC101 Wireless Remote Control Power Outlet Outdoor On/Off Switch with 100 Feet Range,so you don't have to do visiting several stores to get the best price. Moreover, you also must consider payment methods, the store's popularity, return policies, and customer service. Always remember that price is not the only feature to look at in selecting a store. This is a great ways to make certain you find out which online store that give you the best bargain. To get the best price for this product, you'll need make comparison prices offered by various websites. If you consider purchasing this product, the next question is where should you spend your money? There are several online retailers selling this product. Without doubt, SVAT WRC101 Wireless Remote Control Power Outlet Outdoor On/Off Switch with 100 Feet Range is one of high-quality products you can get on the internet.
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