Taking the coach out the box, reveals there is a pull tag to enable the lights, however when I tired to pull it out - the whole chassis came off! At least that works out how to get inside.
This revealed that the battery is located below the seating area - and it turns out this is a good job, and rather essential - CR2032 batteries are magnetic, and otherwise the magnet would be attracted, ot stick to the roof.
Taking the seating out reveals the lighting attached to the top - screwed in complete on a singlar strip - very different to the images shown for R7338 which has a board attaches to another board of LEDs.
R7338 isn't out yet, but given it is only sold as being used to convert an existing coach, I'm rather surprised and a bit confused to why they've gone to the effort of designing it differently. Speculating - maybe they're pretty keen on expanding the Maglight range to more coaches, and having a seperate control board will allow for easier implementation down the line.
I ordered a wheel of 5V LEDs. After doing some reading on these forums about pre-existing latching reed switch solutions, mainly sold by layouts4u, although they run from a 3V battery, as 3V SMD LEDs are uncommon/expensive compared to 5V ones, it is adequate to run 5V LEDs undervolted on a 3V supply.
I went about tracing the circuit board to work out where to attach my lights to, and drew out a diagram of the wiring configuration of the board.
I found that the tail of Q1 contains a negative lead to the LEDs and I can take a lead after R2 for the positive. I'm not brilliant with knowledge of electronics, but I think given the LEDs have individual resistors, R2 may be a bit redundant, but maybe it's some sort of protection from inverse insertion? I'm not really sure - either way I decided to play safe and take from the same place as the pre-existing LEDs.
I also noticed there were rather a lot of redundant traces where it looks like SMD components should be mounted but aren't.
As seen, this worked, horrah! But after looking at the circuit board, it seemed rather oversized for the space it was going to fit, I decided I should attempt to cut it down. I identified I could chop it down next to the soldering plates as they were just blank placed where SMD components could go up to there, and after Q2 as this was just pre-built LEDs. Of course, for the modification to the left end, I needed to take out the reed switch, and relocate it. I also took this opportunity to snip off the LEDs on the other side of the board.
This worked for the first end, and then I forgot to take photos of the process for the second end, either way I ended up with this layout for the maglight inside the coach, some of you may be able to foreshadow what is about to happen.
I re-wired the connection to the battery though the seating area and into the weight box on the coach (with the help of a drill), as to mimic Hornby in getting it away from the area the magnet will be used. I used cheap insulating tape over the magnets
to make sure the weights did not lead to any conduction, and added a plug to allow easy separation of the seating to the base - however with hindsight, this may be a bit pointless in hinsite, as it comes out with the seats anyway. It may be more useful from the seats to the roof, but would create additional challenges in hiding the wires.
A diagram of the complete board modification below.
At this point I thought I was done, so I went to put the seating back in... and... crunch.... eh-oh.
I managed to break the reed switch.... So off on eBay I have gone to order some reed switches, and hopefully I will be able to repair it. Perhaps this reveals (speculative) reasoning behind the seperate board, idiots like me not thinking about the seating before closing up a chassis, I would be surprised if Hornby were not expect people use the R7338 lighting on other coaches, and by making a dedicated board, where the switch is at the end - it perhaps is designed to force the installer to think to place the reed switch parallel to the gangway and avoid the crunch which otherwise may happen.
I will post a follow-up post when/if I manage to get it working.
On a final note, I will note, that at least with my unit, the reed switch magnet operation is not as reliable as one would like. It took many attempts to to pass the magnet over before it would switch between on/off states, I found waving it in a circle above the switch would reliably toggle it within about 20 seconds, about 80% of the time. This makes it hard to see how Mr. Kohler imagines people may hide a magnet inside a bridge to cause activation (as per the press launch video seen on this forum). The only guaranteed method was accidently shorting the magnet over the switch for an instant toggle. I did notice during soldering, that it got easier to toggle - maybe the heat of the iron loosened it a bit? I was going to take a video to demonstrate this, but sadly I've broken it, and it wouldn't be a fair comparison to do it on replacement components.
I hope you've explored my initial explore into the world of Hornby Maglight, I'd be interested to know if others are as excited about maglight as me, or if any other lighting technologies are preferred by others.
- Read more...
- 1 comment
- 980 views