Audible Train Approach Warning Circuit

This is a circuit that will give an audible warning that a train is entering a particular section of track. The detector also has a LED that indicates when a train is entering or leaving the block.

Incline Railway Control Circuit

The mechanism is driven by a geared slow speed motor and controlled by an electronic timer circuit. The car waits for a preset time at the top and bottom of the incline before being slowly lowered down or pulled up the track.

Model Railroad Odometer Car

The Car shows the distance a train travels on a 5 digit LCD display. The distance is indicated down to 1 of 100th of a mile (about the length of a 50 foot car) with an accuracy of approximately plus 2 percent using a standard 33 inch freight car wheel.

Silicon Controlled Rectifier Model Railroad Throttles

The Programmable Unijunction Transistor used to trigger the SCR is the key to this design as it ensures that the SCR fires on every cycle of the fullwave DC. This gives a very efficient operation with low voltage loss and very little heat generated.

Timed DC Throttle

Here is a simple timed DC throttle that has controls for the length of run, accelerate/ decelerate and the maximum train speed. The circuit also has automatic current limiting.

Rail Crossing Diamond Protection Circuit

The Crossing Diamond Protection circuit is designed to prevent collisions where one rail line crosses another. Using phototransistor sensors to detect a train the circuit will disconnect the track power from the line that crosses the occupied line.

Low Voltage Rail-to-Rail Sample and Hold