So you’ve got a DCC++, NCE Power Cab or other relatively small current DCC system and you want to expand but you don’t want to spend a lot of money on a bigger DCC system. There are options out there that will get you a 3 to 5 amp booster for under $100.
One of the first boosters I looked at that takes the DCC output of a system and boosts it was the Tam Valley 5 Amp Trip / 3 A Continuous Duty DCC Booster Board. http://www.tamvalleydepot.com/products/dccbooster.html#booster This board is priced at about $55 US Dollars and you simply connect the output of your DCC system to it and add a power supply. Supplies are available from Tam Valley and resemble a laptop power supply. Further down the booster page is a suitable power supply sold by Tam Valley.
In my experiments with DCC++ I came across an electronics site maintained by Dave Bodnar. Dave has many interesting projects including a booster for the DCC++ system but could be used by any DCC system as it takes a DCC signal and optically isolates it, then boosts it with an H-Bridge output. I was able to get the PCB that Dave used directly from him but be aware that this is not specifically designed for this project and modifications are needed. I have not been able to get the booster operational as yet. During the trouble shooting phase, I shorted the Arduino Mini and destroyed it. I have another on order and will make another attempt. I mention it here for those who are DIY inclined and like to experiment. Details are here: http://trainelectronics.com/DCC_Arduino/DCC_Booster/index.htm
Dave’s site has a wealth of information on it and I suggest you spend some time there if you are interested in model railroad electronics.
While waiting for my parts to come to repair my version of Dave Bodnar’s booster I came across a post on a Yahoo group that mentioned the poster was going to use a booster developed by the MERG group. I investigated and discovered that MERG stands for Model Electronic Railroad Group. Based in the UK they are a group that has celebrates their 50th anniversary this year and over the years have developed a number of electronic projects which have been produced as kits that members can purchase and build themselves. They have a booster kit and as they only sell to members, I bought a booster kit. Shipping from the UK to Canada was reasonable and it came promptly. I talk more about MERG on the MERG page but here is a link to get you started. http://www.merg.org.uk/