This circuit allow an ON-ON type DPDT toggle switch to control a single coil switch machine motor such as those made by Kato®. The handle of switch can then be used to indicate the route selected. The circuit is also able to control LEDs that could be used to indicate the selected route.
The main disadvantage of this circuit is the cost of two large electrolytic capacitors per switch machine. This could be offset by bulk or surplus purchases of the capacitors.
The size of the capacitors depends on the power needed to throw the turnout and the supply voltage. The value of the charging resistors depends on how quickly the turnout will be returned to its last position. A resistance of 1000 ohms would be a practical value in most cases.
NOTE:Although these circuits are show using DPDT toggle switches, 3 and 4 pole switches could also be used to control frog polarity or signals with the extra poles.
The resistors should have a 1/2 watt or greater power rating. The capacitors can be between 1,000 and 2,200 microfarads and should have a 35 volt or higher rating.
The next circuit reduces the number of capacitors needed per switch machine to 1 plus a capacitor that is shared by all of the machines. The value of the shared capacitor, C1 should be at least 4 times as large as that of C2.
The following circuit uses momentary contact bush button switches. Only 2 capacitors are required for any number of switch machines.
The following circuit uses dual power supply and has indcator LEDs. The bridge rectifier can supply other switch machine power supplies.
The following circuit uses dual power supply and has bipolar indcator LEDs.
For more information on other Capacitor Discharge - switch machine power supplies, follow this link. Capacitor Discharge - switch machine power supplies
The explanations for the circuits on these pages cannot hope to cover every situation on every layout. For this reason be prepared to do some experimenting to get the results you want. This is especially true of circuits such as the "Across Track Infrared Detection" circuits and any other circuit that relies on other than direct electronic inputs, such as switches.
If you use any of these circuit ideas, ask your parts supplier for a copy of the manufacturers data sheets for any components that you have not used before. These sheets contain a wealth of data and circuit design information that no electronic or print article could approach and will save time and perhaps damage to the components themselves. These data sheets can often be found on the web site of the device manufacturers.
Although the circuits are functional the pages are not meant to be full descriptions of each circuit but rather as guides for adapting them for use by others. If you have any questions or comments please send them to the email address on the Circuit Index page.
19 September, 2009