I picked up a Liliput G-scale tram (product L193501) which was described as suitable for DCC control, but with no connector. The shop didn't have any info on how this could be done and I've not yet had any reply for help from Liliput in Germany. I've dismantled the tram and the connections do seem simple but being completely new to DCC (which I hope to drive using DCC++ and an Arduino Mega), I don't know what to cut and reconnect. Any suggestions would be welcome. Suggestions on a DCC chip to use would also be good (something simple for speed & direction; there are lights at each end which switch according to direction of travel; I imagine tram sound is not available?) The photo below shows the block holding the wheels has two metal strips which will connect with the two bendable strips of metal on the underside of the tram (marked on my photo as A to A and B to B). There is also a 2-wire cable which pushes into a female connection on the underneath of the tram (C to C). The tram will move if both the metal strips (A & B) and the cable (C) are connected; it does not work if only the strips are connected (and the cable is disconnected); I haven't yet established whether connecting the cable but not the strips is sufficient to drive the motor. Many thanks, Les
You need to determine where the motor is attached to the power inputs. At first glance, it looks to me that the motor is integrated into the truck, which might be an issue. In any case, the motor must be completely isolated from the power connections from the track in order to use DCC, so that's you first task......find out how the power is connected to the motor. If the power input is isolated from the motor, instralling DCC should be relatively easy, BUT the way you described the reverse lighting, I'd assume that you'd need to change the light connections from the main board and connect it to the DCC.......are the lights bulbs or LEDs???
Thanks for the speedy reply. I'm a newbie as far as dismantling engines and terminology (and DCC and electronics!) is concerned, so can you tell me is the "truck" the lower block in my photo? If so, yes, I realise the connection between A-A & the one between B-B would each need to be isolated. What I'm unclear about is what the C-C cable is for and why disconnecting that stops the motor from running. Do you have any thoughts on that? I haven't yet checked what the lights are - bulbs or LEDs. I'll try to do that tomorrow - it's a bit late to head back out to the garage now here in the UK. I'll also try to confirm that the 2 cables that are just visible coming out from the left and right ends of the main board (that's the board in the upper part of the image I assume) and then disappear into the rectangular tubes just go straight to the 2 bulbs. So, if that's the case, those cables would need extending and rerouting onto the DCC chip too. Thanks again for helping out and for any further advice you can offer. Best regards, Les
This is just a guess, but it appears that the track power is transferred to the control PCB via the metal strips. The power is then sent to the lights via the black wires, and back down to the motor via the plug "C". You should be able to verify this by using a DC power pack. Apply voltage to the metal strips and check for lights. Then apply voltage to the connector and check for the motor running. To convert to DCC, if I am right, tou would need to connect the decoder input to the metal plates "A" and "B", the light outputs to the black wires, and the motor output to cable "C."
Hi, It looks to me like the lower A & B strips (which probably contact the wheels) carry the power from the track up to the board. Then the 'C' connector carries the power back down from the board to the motor (via the red and black wires). I can't clearly see the components on the board, but I'm guessing that they are rectifiers and capacitors that supply the lights which if they are LED's would need those components to reduce flicker and allow them to light regardless of the polarity of the track (eg work in either direction). Jim EDIT: Beat me to it SP_fan_1951 !
So concur with Jim and SP fan. IF you can verify the motor is isolated you can just use that connector (red and black) for your motor control and wire to your decoder. As far as the lights go that is going to be a little more complicated. You have two option in my opinion. 1) easiest would be to cut those A and be tabs off. Wire a very simple rectifier circuit with 12V (I'm assuming 12V will work here) regulator and solder that output from the track pickups to A and B. Essentially it would work like it does now. When there is power to the track the lights would be on. No control. 2) If you want to control the lights then you would honestly need to most likely trash the existing PCB in there (unless you are really good at tracing things or have a schematic) and wire the lights (assuming they are LEDs) to the new decoder with appropriate resistors. This would let you do things like dim the lights, do forward and reverse, turn them off and on, etc. This really allows you to take advantage of DCC but obviously is a lot more involved wiring and circuit wise so just depends on how comfortable you are with all that.
Thanks to all for the interesting comments. I think my request to Liliput for advice must have got lost in the cloud somewhere but Bachmann UK has now passed on my query to Liliput & I hope for a reply within a week. I'll then review all the info & see what to do. Thanks again.
