Sc2

One of the modifications that can be done with the SC-2 is to cut the trace from the number 1 position. Note the cut trace center of picture.    This allows the SC-2 to be independently powered, from the included wall wart,  Terminal #1 can be wire similar to all the rest. 

New out of the box, this would void the warranty.  Without the #1 terminals you still have (5) switch positions, if you programmed the unit to all switches.   This unit has it's own antenna and does not require a track connection.

TONY_BBC posted:

...The sc2 manual says accessories and switches must have independent power sources...

It doesn't really say that.

It says accessories and switches must be powered separately - in other words, you need to power them with transformers... the SC-2 does not power accessories and switches.

ADCX Rob posted:

TONY_BBC posted:

...The sc2 manual says accessories and switches must have independent power sources...

It doesn't really say that.

It says accessories and switches must be powered separately - in other words, you need to power them with transformers... the SC-2 does not power accessories and switches.

Rob, I interpreted that wrong also.  I thought their was something in the design preventing them from having the same power source.  I really have limited electronics understanding...   I like your interpretation better.    

I have four 180 watt bricks connected to two tpc400's powering my layout.  One TPC powers the mainline so I could run four or five locomotives on that line.  I wanted the other TPC to power all sidings, yards, and accessories.  I figured I would not have that much amperage drawn on this second TPC.  I have bus wires run around the entire layout for each TPC.     

From Rob's interpretation of the instructions, does anyone see any issue with me powering the SC2 and my switches from the same TPC bus?  

Also, I have all Atlas switches and was just going to connect them to the constant 18 volts provided via the TPC bus.  I was also going to power all my accessories with the same 18 volt connection to that bus wire.  Does anyone see an issue with me powering all the switches and accessories with constant 18 volts in this manner?  

Any and all thoughts are welcome.

Tony, thanks for this post.  It came at the perfect time.  I want to use SC2's to control 15 switches in the yard I will be working on in a couple weeks.  

Thanks,

Bob 

I have cut the trace and powered the SC-2s with power from my accessory transformer which has it's common connected to track common (the U terminals). That seemed to work fine since the base signal was connected to those U terminals as well. Before I connected the U terminals together, the SC-2s were very intermittant to react to the commands from the CAB2. But a further issue presented itself shortly. The switches (Fastrack) that were connected to the number one position switched well, but when something rolled over the antiderailing part of the switch or the switch controllers were actuated in the already switched position, the switch would buzz annoyingly. I since have removed the switches from the #1 positions and installed command upgrades from ERR in those switches. The SC-2 is somewhat an ancient product that has minor issues with the latest Fastrack switches. They work well if you just use them for 83 % of what was the purchase promise.