Favorite Circuits

Please refer to hobby reference materials for correct and safe use information regarding these and all electronic circuits.  These diagrams are intended to explain how things were accomplished in theory, but it is the responsibility of the individual to locate precise information regarding electrical circuits, materials, ratings of components, etc.  Do not attempt these hobby projects, or any electrical project, if you don't have the necessary skills and experience.  The page owner is not and cannot be held responsible for fire, electrical shock, damage, or accident of any kind caused by these circuits or any ideas or information contained on this site.

A Reed Switch Tutorial

Here is a simple way to play a sound effect or train station announcements. The cassette recorder/player is set to play, preferably with a looping tape, like those that were used in early answering machines. This circuit is best used when a train automatically stops (dead center rail) at a station or other layout point. Then the tape will play until the train moves off of the insulated rail. Because precise timing of the tape loop is difficult, the operator would wait for a pause in the tape to resume travel of the train. The insulated rail and relay can be used to trigger almost any device by way of the relay's contacts, either momentarily or for as long as the insulated rail is grounded by a wheelset. The old analog devices still have a place in our hobby, and it is an inexpensive way to achieve sound effects and use the older equipment. Because there aren't any fancy electronics in the old boom boxes or similar players, they are simple to use and trouble-shoot. Not everything has to be digital! And the sound quality of these older boom boxes can be quite nice.

This is the most useful circuit I have ever used.  It causes the relay to "latch" or stay
energized once it is activated until the current is removed.

The above shows how a second relay can "unlatch" the first.  This diagram
shows an insulated rail instead of a magnetic reed switch.

If you would want to operate a handcar for a buffet table, a holiday display, or other situation where you can't have wires running from a transformer or there is no available AC outlet for a transformer, regular D cell batteries can take the place of a transformer for these small motorized units. This idea can also be applied to HO trains. Lionel handcars run on either DC or AC because there is a rectifier inside. They will run very smoothly on DC, better than on AC. Just remember to give the motorized items frequent breaks so they don't run continuously, whatever your situation. Regular safety rules still apply even with batteries! Best to use battery holders, like those from All Electronics instead of just taping batteries together with the positive end against the negative end like in the diagram above.

Pushing the door bell button will remove power from the track, just as if the 'direction' button
on the transformer was depressed.  The wire to the remote can easily be 25 to 30 ft. or longer.

The site owner is not and cannot be held liable for fire, electrical shock, property damage, bodily injury, loss of life, or accident of any kind caused by electrical circuits or any ideas, projects, techniques, or information contained on this site. The visitor assumes all risk and responsibility for any loss, injury, accident or damage arising from the use of information, ideas, techniques, projects, concepts, components, products, and circuits on this site.

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