Saturday, July 30, 2016

How I trigger effects on a MyLocoSound soundcard with a Deltang/RC Trains Rx65b receiver


The latest version of the large scale MyLocoSound Universal soundcard includes five sound effects in addition to the sound of the engine.
On the steam soundcard, these are:
  • a plain or US style chime whistle;
  • a bell or short whistle;
  • a guard's whistle or 'All aboard' cry;
  • a safety valve blow off;
  • a Westinghouse brake pump.
On the Universal diesel soundcard these effects are:
  • a British two tone horn or a US-style single tone horn;
  • a bell (or reverse two tone horn);
  • a guard's whistle or 'All aboard' cry;
  • a turbocharger;
  • an airbrake release.
These effects (in addition to adjusting the chuff rate) can be triggered on the fly using the TV style remote control which is provided with the card.

However, as the TV remote is infra-red, it can only be used at short distances out of direct sunlight. Fortunately it is possible to trigger the effects using a radio control receiver, provided it has 0v outputs (ie outputs which will effectively connect the soundcard trigger terminals to the negative supply from the battery). The RC Trains / Deltang Rx65b receiver / controller has up to fifteen outputs which can be configured to provide this sort of output. By default, the receiver has at least five outputs which are suitable for triggering soundcard effects (Rx65b version 611/11 onwards - shown by 11 / 11 on the main chip in gold), and so, when I took delivery of a MyLocoSound Universal steam card, I decided to interface it with the card.

Wiring up the Rx65b

Consulting the chart on the Deltang website and the RC Trains Rx65b leaflet, I discovered the following output pads were suitable for triggering the MLS Universal soundcard with a Deltang / RC Trains Tx20 transmitter.
  • Pad 3 - 0v output when Ch2 goes low
  • Pad 4 - 0v output when Ch4 goes low
  • Pad 9 - 0v output when Ch3 goes low
  • Pad 10 - 0v output when Ch3 goes high
  • Pad 15 (C) - 0v when Ch5 goes low
So, what does this mean? Let's assume, for convenience, that when it is first switched on, a transmitter is sending no signals on any channel to a receiver which is bound to it - in effect, the channels are in a 'neutral' state. Twiddling a knob, moving a joystick, flicking a switch or pressing a button on the transmitter can make a channel go high or low depending on which direction the knob is twiddled, the joystick is moved or the switch is flicked. So, on the Deltang/RCT Tx20, when:
  • Function button 1 is pressed, it makes Ch2 go low;
  • Function button 2 is pressed, it makes Ch4 go low;
  • the Direction switch is flicked to the left, it makes Ch3 go low;
  • the Direction switch is flicked to the right, it makes Ch3 go high;
  • when the Bind button is pressed, it makes Ch5 go low.

This means that the Deltang / RCT Tx20 is able to trigger certain output pads on the Deltang/RCT Rx65b receiver which in turn can be used to trigger the sound effects on the MLS soundcard - Simple!

Armed with this information, I soldered colour-referenced leads to each of the relevant output pads on the Rx65b;
  • blue to Pad 3
  • orange to Pad 4
  • grey to Pad 9
  • purple to Pad 10
  • brown to Pad 15 (aka Pad C)

Wiring up the MyLocoSound soundcard

The MyLocoSound Universal soundcard has screw terminals for its input triggers. To trigger each sound, the terminal needs to be connected to the negative supply (0v). This could be done by attaching a series of push-buttons or reed switches to each terminal. As the Rx65b receiver can supply 0v outputs from its output pads, I could have connected leads directly from the pads on the receiver to the inputs on the soundcard. However, I knew that the 'internal' voltage used by the soundcard is 5v, whereas the 'internal' voltage of the receiver is 3.1v and so I recognised that there could be a possible conflict if residual current was to flow back from the card to the receiver. To help guard against this, I decided to connect 1k ohm resistors between the soundcard trigger terminals and each of the pads on the receiver. There's a possibility I could be being overly cautious, but having 'fried' a couple of receivers in the past, I felt the minimal cost of a handful of resistors was worth it.

That's all I needed to do - apart from connecting the speaker, the motor leads and the power supply to the card and receiver. If you are using a different battery supply for the soundcard to that used by the receiver, you would need to connect the negative terminals of each battery supply together (but NOT the positive terminals), to ensure continuity of the logic circuitry.

All that was needed now was to play with test the loco:

The output pads of the Rx65b are programmable and so any of the pads on the receiver could be used to provide 0v outputs. If, for example, you find that you have an earlier version of the Rx65b (ie the gold numbers on the main chip on the board aren't 11 / 11), then you could reprogram them (see How to reprogram the output pads on a Deltang / RC Trains receiver). Alternatively, if your transmitter doesn't have five accessory outputs, then some of the effects on the soundcard could be triggered by connecting reed switches between the inputs and 0v and using magnets placed between the rails.

Monday, July 04, 2016

Progress Report 65

A long spell of fine weather has enabled me to get out into the garden for some prolonged running sessions and so there has been fewer opportunities for me to engage in constructional projects - which I tend to do when the weather is too cold or wet for being outside. The better weather has clearly encouraged others to venture out into the garden, judging by the increased number of transmitters I've been constructing and despatching, together with associated receivers, wiring looms and other equipment. However, there has been time for a few projects and some ongoing maintenance to be completed.
  • Apart from ongoing maintenance there has been no major engineering works on the line. 
  • On the lineside, here has been an addition in the form of a motorised road vehicle - a steam lorry. 
  • In terms of rolling stock developments, the new timber wagons have been equipped with pit-prop loads, the newly added Bagnall loco has had a paint job and I have been busy converting LGB Starter Set Stainz locos to radio control.
  • There have been a few developments in relation to aspects of control on the railway. I have had to replace the lithium-ion batteries in Fowler diesel, No. 8 - my first battery failure since going over to battery power, three years ago. I have added a new transmitter to the range which I supply through RC Trains, and I have also constructed some bespoke transmitters for various customers.
  • On the operational front, I have had the opportunity to engage in some running sessions - one of which I videoed and turned into a time-lapse overview of a full timetabled day's operations at Beeston Market station. I have also improved the appearance of the destination stickers I use on freight stock to help with shunting.
Finally, it was encouraging to see an article (which I submitted about a year ago) appearing in the magazine for the 16mm Narrow Gauge Modellers Association. This describes how I added Deltang radio control to my IP Engineering Lollypop railcar (see How I constructed an IP Engineering Lollypop railcar).


Whilst filming the time-lapse video of a day's operations at Beeston Market (see below), I decided to animate the steam wagon which was parked beside the goods yard. I used a crude form of stop-action animation to give it the appearance of movement, but it prompted a fellow modeller to enquire as to whether I had considered making it radio controlled. Never fearful of rising to a challenge, I decided to investigate the feasibility of such a venture (see How I converted a ModelTown steam lorry to radio control).

The conversion is not particularly elegant as I used it more as an investigation than a serious attempt at motorisation. The resin-cast model is representational rather than an accurate scale model and so there is plenty of scope for its enhancement. One day, I will set about improving the model, both cosmetically and mechanically.

Rolling stock

Timber wagon loads

 After purchasing four small Feldbahn timber wagons (see Progress Report 64), I felt they would be improved by repainting, weathering and having loads. I have been considering constructing some wagons to transport pit-props from the timber yard to the copper mine and for transshipment to the main line for some time and so these were an opportune addition to the line.

The pit prop loads were conveniently cut from various twigs and branches which were found in the woodland nearby (see How I provided pit prop loads for my timber wagons)

 Bagnall new livery

My newly acquired Bagnall loco was in urgent need of a new paint job and so it went through the railway's paint-shop and has emerged in the standard Rover Brooklands Green livery reserved for the line's locomotive roster.

As the prototype on which it was based was 2' gauge and had outside frames, I have tried to disguise the driving wheels by painting everything below the running plate matt black and picking out the motion in bright red. I have also added a few extra cosmetic details such as reversing levers and clack valves to focus attention away from the lower part of the loco.

She is a good runner and looks very much at home in charge of passenger trains in the timetable. The early version of the MyLocoSound card has a throaty chuff, although I struggle to keep the cylinder beat in time with the loco's speed.

Stainz conversions

After posting information about converting my trusty LGB Starter Set Stainz loco to radio control (see How I converted an LGB Stainz loco to battery power and radio control), I had some enquiries from fellow modellers, asking if I could perform the same surgery for them.

 I have now converted four Stainz locos to battery radio control and so am becoming reasonably proficient at dismantling and modifying these neat little locos. The later versions seem to have a much throatier sounding soundcard, though I have not yet found a way of modifying the card to give the loco a background hiss when stationary.


Replacing lithium-ion batteries in No.8

 When I originally constructed my IP Engineering Jessie loco, I used NiMh batteries - managing to squeeze ten AA sized batteries under the bonnet (see How I constructed an IP Engineering Jessie loco).

However, all but one of my other locos are powered by lithium batteries and so, for uniformity, I installed three 18650 lithium-ion batteries which I bought very cheaply on eBay. They do say you get what you pay for and I very quickly found that the 3000mAh claimed for the batteries was an exaggeration. After testing them, I discovered they were closer to 1600mAh. However, they did function satisfactorily, albeit needing to be recharged more frequently than I had anticipated. All was well for a year or so until, during a running session, the loco started losing power. Normally, the protection circuitry and/or the receiver will cut-out lithium-ion cells when they drop below a safe level of charge (around 3v each) and so this loss of power indicated something more serious was at fault. Removing the cells and putting them on the meter showed that, while two cells were a healthy 3.2 volts, one had dropped to 1.67 volts. I realised there was no way this cell could be recovered and so all three were discarded and three new 18650 Panasonic batteries were purchased from Ecolux - who guarantee the quality and legitimacy of their batteries. I know from experience that, when making up battery packs, the three cells need to be identical - mixing cells of different characteristics is a recipe for disaster.


After some deliberation, I am now offering my version of the Deltang Tx24 transmitter on my RC Trains website. I had always planned to have this transmitter as part of my range, but as I don't have live steam locos (yet), I felt I wasn't qualified to offer advice for version of the Tx22. However, after requests over the months from customers, I have constructed and sold three RCT-Tx24s - one of which has been successfully in service now for over four months - and so I felt confident that the transmitter would be a useful addition to the range.

The difference between this transmitter and the RCT-Tx22, is the replacement of the two way toggle switch for direction with a centre-click potentiometer. This makes it a lot more suitable for controlling servos operating the reversing lever on live steam locos. It can also be used to switch direction on receivers which are programmed for low-off operation and can also be used to control outputs from the RCT-Rx65b receiver to, for example, trigger sound effects on soundcards.

Since placing the transmitter on the website I have had a further three orders - and so there is clearly a demand for this transmitter.

Bespoke transmitters

I have also produced transmitters for customers who require some additional bespoke features. In one case, this was the addition of another push-button to trigger Channel 4 and another couple of cases, they wanted transmitters produced in the same liveries as their railways:

I charge extra for this bespoke service as it does involve additional work, but it makes my work a bit more interesting.


 Destination boards

 As freight operations are an important part of operations on my railway, I have explored various approaches to making sure goods wagons are shunted into the correct sidings when, for example, the pickup goods makes its rounds. I was attaching a white sticky label showing the destination to each wagon but, of course, they did not look particularly realistic.

After a suggestion from a war-gaming friend, I created a series of self adhesive destination boards which were mounted on pieces of tinplate. These are attached to wagons with small magnets (see How I created destination boards for my freight wagons)

Operating sessions

 With a spell of fine weather during June, I was able to indulge in a series of running sessions - one of which I captured on video and then turned into a time-lapse film showing operations at Beeston Market Station.
 Four coach special passenger at Bickerton with Barclay loco No. 2 (Beeston) in charge.

 The Up four coach special crosses the Down mixed at Bulkeley station

 Aerial shot of the above manoeuvre.

The Down mixed arrives at Bickerton as the Up pickup goods is about to depart

Time-lapse video of movements at Beeston Market station during a complete day's timetable

Since the middle of June the weather hasn't really been conducive to decent running sessions (sunny periods with heavy showers - or prolonged periods of rain). However, this has given me an opportunity to focus on organising the stock for my online business and also explore other avenues such as developing a soundcard.

Whenever I do run trains, I tend to take photos and short sections of video as the trains pass by. One of my future tasks is to try and organise these clips into another video showing life on the Peckforton Light Railway

There is always plenty to do on a garden railway.