The 73's have Arrived

On Monday morning I received a phone call from the boss at home advising that a package from Auscision Models had arrived. So I left work reasonably early at 4:00pm and made my way home. Upon my arrival I unpacked the models and took then straight down to the shed to run them on DC. They ran very smoothly and I was most impressed with them. I then gathered some tools together:- Wire Cutters, Soldering Iron, Solder, Tweezers, DCC wire, two decoders, a DC throttle, a multi-meter, 2 x AA batteries in a battery holder, a 1K ohm resistor and a small 3mm white LED, and then spent some time with the family over dinner.

 

After dinner I read the instructions that came with the models. I used the foam lid from the box as my work area, and proceeded to disassemble the model by removing the KD’s and the chassis. At last access to the internal wiring. I had a close and look and thought that I will be able to install the motor decoder quite easily and then look at my additional decoder for the rest of the lights. I removed the circuit board and cut off the front headlight board. It was very easy to remove the two red wires and the two black wires from the wheel pickups and then remove the red and black wires from the motor and connect them to the orange and grey wires from the decoder. I chose an NCE N14SR decoder as it had 4 function outputs.  However, when I connected them red to orange and black to grey the loco ran in reverse. What a stupid decision by the Chinese designers.

 

My plan is to use the N14SR decoder to power the motor and the lights at one end, and a 4 function FL4 for the other end.  Maybe a Z14SR decoder may have been a better options as it is about half the size of the N14SR decoder.

 

Then my attention turned to the front light board that I removed. I decided to try and workout what wire was what. I numbered the 5 wires from right to left. That is correct right to left when viewed from the rear, with the lights facing forward away from me. After some trial and error, I worked out that when my 3V battery with its 1K ohm resistor was connected black to wire 1 and red to wire 4, we had white marker lights. When I connect the wires in the reverse order, black to wire 4 and red to wire 1, we had red marker lights. Immediately I thought that was not good. Again a stupid decision by the Chinese designers. It appears that these two LED’s were wired back to back on the little light board at the front and rear of the loco. I would have thought that it would have been smarter to do all the magic back on the circuit board in the loco and run one extra wire to the light board at the front or rear of the loco. Sure that might have made one of the switches into a DPDT switch, or put a fourth switch in. That way it would be easier to DCC the loco eventually.  I'd bet that there will end up being more DCC versions than DC versions eventually.

 

When you run the black wire from the 3V battery to wire 1 and the red wire to wire 5, we get the headlight lighting up. When you run the black wire from the battery to wire 2 and the red wire to wire 3, we get the number boards being lit.

 

So with my small brain, I immediately wondered if it was electrically possible to use two decoders to get the red and white marker lights working alternately or even similtaneously. Can I connect the blue wire from decoder 1 to the wire 1 and the green wire to wire 4. At the same time can I connect the blue wire of decoder 2 to wire 4 and the green wire to wire 1. Of Course both green wires will have a 1K ohm resistor installed on them. Does this proposed implemetation cause issues?  So my plan is when I turn on function 1 in the first decoder, I get the white lights. When I turn on a remapped say function 3 (for example) on the second decoder, I get red lights. So I ask the vast collection of electrical gurus in this WWW thing “Will this work, or will it cook two decoders?”

 

I can be happy with controllable headlight, number boards and white marker lights with no red marker lights at each end, but if I can I would like to get them working as well.

 

I just feel this is poor planning for the DCC world in which we now live. Boo to those Chinese designers.

 

I had planned on taking some photos of my dissassembed 73 tonight, but cannot be bothered, I've had a bad day at work working with imbeciles, late buses and I am totally spent.  Last night I took the 73's to Lefty's place for Tuesday Nighters and ran it on his layout.  It ran very smoothly in DCC mode except for being in reverse.  I will fix up the two wires to the motor on Friday night and further investigate the lighting controls.