These circuits allow single coil switch machines to be controlled using a SPDT and SPST, normally open, push button swithes.
The circuit using a DPST switches is fairly simple and may be less expensive to control a small number of turnouts. There are fewer options for DPST push button switches though and some can be quite expensive.
The DPST push button circuit is equivalent to using a DPDT toggle switch that returns to the OFF opsiton when released.
The SCR (Silicon Controlled Rectifier) circuit is more complex and would need a circuit board but it uses less expensive components.
These circuits should be powered by a current limiting, capacitor discharge type switch machine power supply as closing both push buttons at the same time will create a short circuit.
Shown is a simple RC type supply but electronic current blocking supplies will also work. The supply can be connected to any number of control circuits.
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.
30 December, 2016