Construction of the station building part IV

Two garden LED lights that have been in service in my garden the last year will become the interior lights for the building. The upper part of the light fixtures themselves will be used as they hold the solar panel. They will be placed on top of the building to collect sunlight.
After opening the light fixture it is clear that it used a 1,2 V 40 mAh battery. The power switches were rusty (but these are actually quit obsolete as I never used those) and will be removed. Considering the rusty state of the battery cells it will be a good idea to replace those with reachable AA or AAA cells.

The wires from the solar panel to the circuit board will be lengthened. As mentioned above the fixtures with panel will be placed on top of the building (disguised as chimneys) and the longer wires run to the circuit boards that will be placed in the building, together with the new batteries, in a way it is easy to access for repair or maintenance.

Opening the light fixture

The battery shows it is a 1,2 V cell. It will be replaced by a 1,2 AA or AAA size cell

Old cell removed. New one shall be connected with wires to B+ and B-
The solar panel will be connected to S+ and S- (here still connected to red and black wire).
The white wires went to the obsolete switch and are now connected together, without the switch.

Lengthened wires connected.

The LED light fixtures are than placed on the roof using hotglue. I added an extra layer of hotglue on the 'chimney's to give more grip if I make the chimney of of cement or Milliput (see later on).

 

I carved the foam to give the cement more grip on the surface.

Roof tile pattern was 'sculpted using an old screwdriver. There is not only a pattern but also some relief in it. 

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Solar powered railcar Part VI

Testrun

Last night I made several test runs. After removing the useless diode (see part V) the car did had power enough to run its rounds. However the space between the front wheels (motorized axle) was a bit to wide causing the wheels to block in the curves. This was fixed by adjusting the distance between the wheels a bit.

First video: an early test run with flickering headlight (loose contact) and loosing one of the sliding doors! Sorry for the horrible sound...

 

Later that evening it finally runs well, especially considering the very moderate 1,5 volts power source! Again sorry for the sound...

 

Next (and final) step; windows and final detailing...

Solar powered railcar Part V

Some progress on the electrics. It is not my most favorite part as I lack the knowledge of it. It is trail and error for me.

As planned I connected the motor directly to the battery and added a small switch to turn the motor on and off. Due to the fact I misunderstood some good advise of a railway modeller on the Garden Railway Forum I had placed a diode (wrongly!) between the battery and the motor to avoid unwanted discharge of the battery. However this was a complete useless thing to do. The diode had no function on that spot at all... it only let the voltage drop with 0,7 volts, causing too low voltage to run.

The diode had actually made more sense between the panel and the battery cell ifI had chosen to charge the cell directly from the panel (which I did not as I let it charge using the connection on the board). When charged directly from the panel it is also better to use a Schottky diode instead of the BY diode I used as the Schottky has a way lower voltage drop (0,2 volts). Trail and error!
 
A 1,5 volts 2500 mAh battery cell is used (the original cell that came with the set was 600 mAh). Hopefully this will extend running time (but also will extend charging time). If not, or when charging takes way too long or don't charge at all, I will replace it with the 600 mAh again.Although I found the LED a bit too blue-isch I used it as headlight because, well... I had it.
Perhaps a bit of coloring will get a more warmer color and if not it can be replaced after all.

Overview; be aware: the green diode is REMOVED (see text)

LED in place

Switch for the LED glued in place. The motor switch will be next to it.

Overview on how the parts fit together

Charging up in the first June sun

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Solar powered railcar Part IV

Coach - work in progress

It has been a few weeks, so time for an update!

After building the chassis I started to build a coach. As said the model was loosely based on a Billard draisine that could be found on multiple French metre gauge and narrow gauge railway lines. I choose this simply because I liked the looks of it.
To keep is as light as possible the coach is build op from balsa sheets and cardboard (the backsides of paper notebooks). The coach will be attached to the chassis with small screws from underneath.

The in- and exterior were painted in a grey primer (Humbrol #1). The interior kept this grey color while the outside was painted in white and red livery. The model has sliding doors like some of these Billard draisines had. I left out the engine grille because, well... it is solar powered and not petrol powered after all ;-)

The pictures below shows the work the last weeks. The coach itself is for 90% done. I am still not sure what to do best with the wiring and I still need to figure out a removable roof (for access) that holds the solar panel.

But so far so good:

Priming the doors

 

Painting the coach in my 'neat and tidy' workshop...

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Solar powered railcar Part III

Chassis

The plywood parts of the Solar House kit turned out to be very handy as a support for the motor and gearbox..With a bit cutting and filing all fits nicely. This base is 72,5 mm square. I will use a similar part and a sheet of balsa wood that I have lying around to expand the chassis. It will become somewhere between 130 or 150 mm in lenght, just what looks fine and runs well.
I just use plastic LGB wheels while I had those left over and to keep it as leight as possible.

Also made an axle mount out of styrene sheets. Again all very basic and light weight.

A little video of the test run which was made without the solar panel. It was powered by a normal 1,2 Volt battery for testing (I could not discover how much the capacity of this battery was).

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Solar powered railcar Part II

The motor

The Sol Expert kit was pretty straightforward to build. The instructions are simple and clear. You can choose between several gear ratios. The kit comes with a little wooden template to adjust the motor gear in different position depending on what ratio you choose.

The axle that came with the kit was a bit to thin for the LGB wheels I wanted to use so I made a spacer from a piece of  styrene tube. It works but I am not totally satisfied because one wheel has still a bit slack. Perhaps I will replace it in the future with a brass spacer. But for now it is good enough.

And the end result; motor, axle and wheels all in place and looking just fine.
Now I really need to figure out how to make a simple chassis...

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Solar powered railcar Part I

The original plan

Due to a few Youtube videos of solar powered garden trains I became fascinated by this idea and started an experimental solar powered model rail vehicle. After some (not to successful) searching on the internet for information on similar projects I realize I had to figure it out myself as much as I could. Because I am not very skilled in electronics I decided to buy on Conrad a “Solarhouse” and a motor with gearbox. Both kits are from Sol Expert (#40212 “Solarhaus” kit and #90015 “Universal getriebe”). See pictures below.

The house kit was bought because it has some electronic unit in it that charges the battery (or at least, that was what I thought it was, just keep reading...). 
This kind of electronic unit is certainly also present in most cheap LED garden lights of course, but mostly the electronic components in these have no visible codes or markings on it. As I want to examine what components can be used for making a similar unit myself, I wanted something with these codes still visible. I noticed this was the case on the Sol Expert kit.  
The kit itself is very straightforward (luckily); with a switch you can turn the LED on and off. I figured that I could replace the LED for the motor which will make the wheels spin and that would be it for me (I like things simple). No RC control desired at this moment, just want to let it work for now. The Sol Expert 0,6 – 6 volts motor is designed to run on the solar charged 1,2 volts battery. If I keep the model as light as possible, it will work (I hoped).

The second plan (after some wise advise)

Fortunately I received some very helpful advise on the Garden Railway Forum that made me understood the electronics a bit more. There is NO special charger unit in it as I had guessed. The solar panel just charges the NiMH battery. The two components are a LED driver that shuts off the LED when the voltage drops below a certain point, and an inductor.
The advise was to run the motor straight off the battery and not to replace the LED with the motor hence the chip has some current limiting function.
So, the plan is now to keep the electronic unit as it is (it will be a headlight for the railcar) and connect the motor directly to the battery together with an on/off switch. See the drawing schedule below.

Next, figuring out how I build it on some sort of base or chassis and what it would look like...
To be continued!

Sol Expert Solar House electronics #40212

Sol Expert #90015 Gearbox and motor

LED driver

Inductor

The first setup

It works!

The plan...

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