DERBY FINISH LINE DETECTOR by LM339
The following is an electronic schematic and parts list for the items needed to construct an infrared detector for the finish line of a Pinewood Derby racetrack utilizing an external power supply and the parallel port of an IBM compatible computer of at least 486/33Mhz running DOS 3.1 or better. Also included is a narration concerning the construction of the detector as well as the BASIC code required to operate the detector.
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Read more original source:
http://www.geocities.com/Yosemite/Trails/7471/pwdtrack.htm
Categories: Detector Tags: light control, lighting senser, LM339
Bargraph Voltage Indicator by LM339
The circuit Bargraph Voltage Indicator used IC op-amp two quad voltage comparators to illuminate a series of 4 LEDs indicating volume level.
The op-amp used in this particular circuit is the LM339. It is a popular IC and should be available from many parts stores.
The 1K resistors in the circuit are essential so that the LED’s turn on at different Voltage input levels.
The sensitivity can be decreased with R1 and the input control to read higher levels.
This circuit is easily expandable with more op-amps, and is not limited to use with the LM339.
Detail more,Plaese read in image.
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Basic Memory Functions by LM339
Comparators can be made to perform a basic memory function by wiring them as a ‘SET / RESET’ type of FLIP/FLOP. This type of circuit can be used in unplugable walk around throttles to remember the direction of the train when the controller is disconnected. In the next diagram the comparator will remember which switch was pushed last. If the ‘SET’ button is pushed the LED will be on, the ‘RESET’ button will turn the LED off. A higher current version is also shown.
Source:http://home.cogeco.ca/~rpaisley4/Comparators.html
Thank you.
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Categories: Basic electronics, Digital, Electronic Control Tags: Basic electronics, digital circuit, Electronic Control, LM339
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