Railroad Controller with Presence Detector
Created: Sep 08, 2014
No description available.
Railroads are a huge piece of the history. They take us back to a prior time where once trains were the quickest approach to cross a gigantic area. Model railroading could take you back to those more good old times, and it is a greatest hobby. Probably, you have already perceived that this will be a standout amongst the most rewarding and relaxing hobby that you will ever experience. Model train shows are very common, and you can watch the excitement of visitors when their eyes glued to the moving locos.
The circuit uses a MCP6241/2 opamp that has a 650 kHz Gain Bandwidth Product (GBWP) and 77 degrees phase margin. This family operates from a single supply voltage as low as 1.8V, while drawing 50-µA quiescent current. In addition, the MCP6241/2 family supports rail-to-rail input and output swing, with a common mode input voltage range of +300 mV to –300 mV. These op amps are designed in one of Microchip's advanced CMOS processes. The Microchip Technology Inc. MCP6241/2 operational amplifiers (op amps) provide wide bandwidth for the quiescent current.
The controller circuit also ensures that the stop block remains in the power-up state until the train exits the stop block, and the stop block is in power-down mode thereafter. For this second task, an ordinary reed switch lies between the tracks is connected to the main controller circuit. When the train passes over the reed switch, a magnet placed at the bottom of its frame activates the reed switch and this toggles the controller circuit to remove power from the stop block. When it comes to an exhibition hall, LASER triggering is more precise than a PIR sensor. The laser is pointed at an LDR (Cds cell) and when the beam is broken, the electro-magnetic relay activates and stays activated as long as the beam is broken. The laser card/head module can be located at probably greater than 20 feet from the LDR and will work in fairly bright ambient light.