Control Panels

Last updated: 3 May 2011

The following picture shows my first control panel. It sits in front of the tracks in my back room on their way from the garden to 7 storage sidings in the garage.

The panel to the left of the ZTC511 controller has a red push button and a green LED for each of the 7 sidings.

The pushbuttons are connected to CTI through a CTI Sentry. When CTI is powered up you can press a pushbutton to change the appropriate points for that siding. CTI lights the red LED above the pushbuttons until the points have changed. This is helpful because each motor is given time to change and the longest sequence is 4 points so it is useful to know that the sequence is complete when the LED goes out. I have also implemented a track diagram on the PC screen using CTI and you can change individual points or set a route using that.

Since these are hidden storage sidings switches on the point motors are used to cut power from all but the current siding. At any given time the currently live siding is indicated by the green LEDs which are simply connected across the rails for each siding.

Eventually the buffer stops at the end of the sidings will also cut power to their sidings. A buzzer on the panel will buzz when the stops are pressed. A pushbutton will override the power cut so that the train can just be eased off the buffers.

A CCTV camera has been installed over the sidings so that the operator can see what is happening from a screen above the control panel.

The panel to the right of the ZTC511 controller controls the tracks between the hidden sidings and the garden. The rightmost point is actually through the wall on the bridge over the patio and is at one corner of the triangular junction. The implementation of this panel is not yet complete.

The track diagram indicates the state of points, signals and some isolating sections. These sections will be useful for storing locos without decoders and putting stock on or off the track. I am also planning a DC option for running visiting DC locos.

The row of switches below the diagram control the points and signals. The rightmost 2 switches switch the panel out and switch power to the points and signals.

When the panel is switched out the points and signals move to a preset state. Control of some of them will be passed either to the junction panel or to CTI, or both.

The bottom row of switches are master switches for providing power to accessories and each DCC power district. They include a switch for programming mode. This allows the spur at the right hand end of the loop to be used as a programming track. The 5 switches to the right control power to the isolating sections.

Above the track diagram is a crude set of block instruments. These will provide communication between this panel (signal box) and the loops and junction panels (boxes) as described later.

The next picture shows the loops panel. It is not fully wired up yet and the LEDs on the track layout and block instruments have not been installed. The layout of the panel is similar to the back room panel. On the track layout the centre two lines are the up and down main. Point 2 leads around one side of the triangle to the patio bridge and then indoors. Signal 3 controls the exit from a planned goods marshalling yard with three sidings. There is a loop off the up and down main lines. Control of the other end of the loops belongs to the Bournemouth panel.

The block instruments have not been wired up and tested in use but the proposed procedure is as follows.

Each instrument has two LEDs and a 2-way centre off switch. The normal state is with the LEDs out and the switch in the centre off position. The Loops Down instrument on the back room panel and Down Branch on the loops panel constitute a pair.

To move a train from the back room to the loops the back room signalman moves his Loops Down switch to Is line clear? This lights the Is line clear? LED on the Loops Down Branch instrument.

When his line is clear the loops signalman moves his switch to the Line clear position. This lights the Line clear LED on the Back Room Loops Down instrument. The back room signalman can now set his points and clear the signals for the train to be driven from the back room to the loops. He sets his switch to Train entering section which puts out the Is line clear? LED on the Loops Down Branch instrument and lights the Train entering section LED.

When the train has arrived and the loops signalman has checked that it is complete he sets his switch to Train out of section. This puts out the Line clear LED on the Back Room instrument and lights the Train out of section LED. The back room signalman now returns his switch to the normal position which puts out the LEDs on the loops instrument. Finally the loops signalman returns his switch to normal which puts out the LEDs on the back room panel and returns both instruments to their normal state.

This procedure is missing the bell codes to identify what train or route to expect. I am still thinking about this but it could be addressed with multiple Is line clear? switches, one for each type or route. Initially I will rely on the sequence table and the odd shout!

I am also considering using CTI to substitute for the back room signalman when the panel (box) is switched out. The junction and loops instruments would then interface to CTI instead of the back room block instruments Only a simplified functionality would be provided such that a pushpull train could be accepted and released from the indoor section and an engine could be turned used the shunt ahead.

The loops panel is now outside. It lives on a shelf above the loops. Here are some pictures in various states of undress.

Hopefully the cover will be weather proof. It is made from plastic sheet from Squires reinforced with plastic sections.

Inside we have a MERG Accessory Decoder, a CTI Sentry and a couple of relays (under the veroboard on the left). The other veroboard, partly obscured by the Sentry, contains the diodes. The relays control the 2 remaining Hoffman motors. They will be removed when I replace the Hoffman motors with servos as described in Point Control which also includes a schematic for my wiring of accessory decoder, local switches and relays.

The relays can be operated by the decoder at all times but the local switches operate only when the panel is "switched in". The relays operate the 2 points with Hoffman motors using a separate feed. These motors are still working despite the problems I had with the third one.

For normal working the points are controlled using the switches on the panel. When the panel is switched out they are controlled from CTI's CTC panel. In an emergency or during maintenance the points can be controlled directly using CTI, a DCC throttle or via JMRI using my iPOD. This is proving really useful.

Note that although DCC is not used by the local switches they do draw their power for the relays from the accessory decoder board.

The Sentry is used to detect the state of the "switch out" switch. Later it will also be used for the switches which form part of the block instruments.

This is a very cost effective solution for controlling accessories using DCC. The decoder can control up to 8 relays.

Further decoders will be needed in this panel as more points and signals are commissioned. I may also use the decoders to control the LEDs in the block instruments rather than the more costly CTI Signalman. However I don't want to overload the DCC bus and the Signalman is more compact.