As Tortoise (by Circuitron) switch machines are the "stall-motor" type they are normally operated using a toggle switch because it is desirable for constant electrical current to be powering the machine, thus ensuring that the points are held tight to the rail. A momentary push button switch would not normally work with this type of switch machine.
I am an enthusiastic subscriber to Model Railroader Video Plus, the online video service of Model Railroader Magazine. I have learned a great deal from the many high quality, professionally produced videos. In my opinion this service is well worth the cost.
One of the video series I followed in MR Video Plus was the step-by-step design, construction and scenicking of their Canadian Canyons N scale portable layout. While I do not currently model in N scale, all of the information provided is transferable HO scale. A couple of the episodes in the Canadian Canyons series provided a very detailed step-by-step description of how to use push buttons to operate Tortoise switch machines.
At the heart of this setup is a Digitrax DS64 Quad Stationary Decoder, as follows.
A Tortoise switch machine has 8 electrical contacts on a contact strip. The two outermost contacts are wired to the outputs of the DS64 - this is how the switch machine is moved. The inputs to the DS64 can be a momentary on push button switch. Any such switch will do.
The MR Video Plus episodes introduced me to a very neat type of push button switch sold by Mouser electronics (Mouser part number 612-LP1OA1AG)(the "O" is an "oh" not a zero). Here is the data sheet from the Mouser site:
These switches have four electrical contacts on their base. Two of the contacts constitute the outputs of the switch itself (they close the circuit when the button is pressed) and the other two are wired to a green LED mounted inside the clear button. There is no internal circuitry to operate the LED.
Reference was made above to the 8 contacts on a Tortoise. The other 6 contacts are actually two pairs of 3 contacts. These can be used to power the switch frog, operate signals or in this case to operate the green LED mounted in the push button. It is necessary to include an appropriate resistor in the LED circuit to protect the LED from excess current. I use a 560 ohm resistor when the LED is wired to a 12 volt DC circuit.
In the MR Video Plus design they used only one Mouser switch to power each turnout. Pushing the button once moves the turnout in one direction. Pressing again moves it in the other direction, and so on. I decided it would be better to use two Mouser switches for each turnout drawn on the control panel, as follows:
The green LEDs are powered by one of the three contacts on one side of the Tortoise. The momentary off-on switch for each pair are mounted in parallel to the inputs of the DS64. The blue light is unrelated to the turnouts - it shows that an uncoupler is powered.
I find this method of operating turnouts nice to operate and nice to look at. Thank you MR Video Plus for introducing me to this concept.
Here is one location under my layout where I have three DS64s, enough to operate twelve Tortoises:
