I've been digging around, looking to build my own custom throttle box. I do electronic and field service for our Kids Run Trains group.
Before continuing, please understand that some of what we are doing here is considered a crime to purists and a sin to modern electronic logic. I'm joking about this, but some of you might question this setup... a lot.
Our rules are:
-Educate and further the hobby
-Keep the train on the track
-Enjoy running trains
Our control system is visually complex, but when you look at the diagram it's dastardly simple. Keeping costs down has led us to use pre-fab components that are rapidly replaceable within 2-5 minutes, or swap with a spare unit on hand while repairs are made to the first. We can buy a pile of Z-Controllers for 20$/each used.
Four Powerhouse 180's feeding a modern 425 watt ZWL that sits inside the layout. We control total track power available to the other set of controls.
Posts A and D pass to the outside of the layout to two MTH Z-Controllers that are simply there to provide throttle for kids to run the trains. These outputs connect to the two tracks on our LCCA modules.
Power handling is not the current problem.
Some of the things I need to fix:
-Reverser lockouts
-Z-Controller is not rugged enough
-Z-Controllers have a 4 second "Boot up" and also dumps a modified sine wave.
As many of you know, not all trains have E-Units and respective lockouts. Not all E-Units are electronic. I need a way to keep voltage on the track to stop conventional units from cycling. I've been thinking of a fixed resistor array with enough wattage handling that I can cut in/out with the flip of a switch.
Our current resolution to this is to take the Z-Controller control knob and setting it to a minimum power. Then we remove the control dial and clock it (re-index) to the new "off" setting. The problem with this is that this breaks the rheostat on the Z-Controller when it gets turned past the stops. It doesnt take much effort. This segways me to the next topic...
Z-Controllers are not super durable, but they get the job done. The electronics in them are solid, but the buttons break when you get some gorilla mashing them (makes mental note to fix the buttons from last show).
Due to this 4 second "boot up" of the Z-Controller, it causes a lot of operational errors on our part. Vigilance takes care of this, but you get the occasion where we forget.
Z-Controllers require 9v input before it turns on. There are conventional units that fly away at 10v. Because of this, I'd like lower voltage control.
The ZWL outputs modified sine. Pump this into a Z-Controller and the output looks really freaky on the scope. Despite this, the trains really dont seem to care and it does not interfere with TMCC/DCS. Final voltage at the track is a paltry 17v unloaded.
I'm looking to replace the Z-Controller portion with a slightly more robust (and durable) setup.
https://ogrforum.com/...98#71538114105517698
John's Bell/Whistle array would be incorporated into the box (May I please?). We do not care about the 1-2 volt drop.
I am unsure of the value for the variable resistor and would like some input as to how big to rate this. This, along with the bell/whistle buttons would be added to the control box and placed outside for public interaction.
The 8ohm resistor is to maintain a 7 to 8 volts on the track to prevent cycling of the E-Units. Again, this has been proven effective until there is a short or derailment. This would be used if the engine does NOT have an effective method to stop it from reversing. Please suggest better values for the resistor if you feel it's not up to the task.
Command Mode switch would bypass external public control. This would permit us to run via ZWL handles or handhelds.
Again, I am looking for a value for the VR and any suggested parts. Open to suggestions as well.
