The RailBoost5 Power Booster is based upon the TMW-DCC TMW05 MidiBooster, a 1.5 Amp booster, and the TMW06 Power Supply. I've modified it to a 5 amp booster with a larger power supply. The booster currently DOES NOT have short circuit protection, and I recommend that you use it with a DCC Circuit breaker such as the Tony's Train Exchange PSOne. Exposure to a short circuit for more than a few seconds will result in damage to some of the electrical components, and in some cases explosion of the silicon casings due to excessive heat buildup.
I've assembled several of these boosters for use on my layout and for friends. Creating a system beyond the breadboard can be extremely challenging. To assist, I've created circuit board designs for the two modules (the power supply and the booster) that can be uploaded to ExpressPCB. The latest designs on this website have been upgraded to accomodate full 5 amp pathways from the power supply through the booster, however, I have not tested them as of yet, but will do so shortly.
(To utilize these designs, download the free software from ExpressPCB.)
Power Supply
The power supply accepts 12-15V AC input and provides 5 amps of +15V and -15V DC for the booster, as well as 2 amps of 5V DC for a few IC's.
Power Supply Schematic and PCB Design
Booster
The booster is connected to the outputs from the Power Supply and the transmit pin from the PC serial port. The serial port signal is amplified and used to turn pairs of transistors on and off at high speed to create the DCC data signal.
Booster Schematic and PCB Design
Components
The following is a listing of the components in the design and their Digikey order numbers to assist in ordering.
| Board | Part Label | Description | Source | Order Number | Quantity |
| Power Supply | J1 | Terminal Block - 2 Position | Digikey | 281-1414-ND | 1 |
| Power Supply | J2 | Terminal Block - 4 Position | Digikey | 281-1416-ND | 1 |
| Power Supply | RECT1 | Rectifier - 100V 8A | Digikey | MB81-BPMS-ND | 1 |
| Power Supply | C1, C2 | Capacitor - 5600uF 50V | Digikey | P6933-ND | 2 |
| Power Supply | C3, C4, C5 | Capacitor - 470uF 35V | Digikey | 493-1084-ND | 3 |
| Power Supply | Q1 | Transistor - PNP TIP2955 | Digikey | 497-2608-5-ND | 1 |
| Power Supply | Q2 | Transistor - NPN TIP3055 | Digikey | 497-2586-5-ND | 1 |
| Power Supply | R1, R3 | Resistor - 1 Ohm 5W | Digikey | TWW5J1R0E-ND | 2 |
| Power Supply | R2, R4 | Resistor - 10 Ohm 5W | Digikey | TWW5J10RE-ND | 2 |
| Power Supply | REG1 | Voltage Regulator - 15V 1.5A | Digikey | 497-1454-5-ND | 1 |
| Power Supply | REG2 | Voltage Regulator - 5V 2A | Digikey | 497-1468-5-ND | 1 |
| Power Supply | REG3 | Voltage Regulator - -15V 1.5A | Digikey | 497-1478-5-ND | 1 |
| Booster | J1 | Terminal Block - 6 Position | Digikey | 281-1417-ND | 1 |
| Booster | J2 | Terminal Block - 2 Position | Digikey | 281-1414-ND | 1 |
| Booster | R1, R2 | Resistor - 200K Ohm 0.25W | Digikey | 200KQBK-ND | 2 |
| Booster | R3, R4 | Resistor - 330 Ohm 0.25W | Digikey | 330QBK-ND | 2 |
| Booster | R5, R6 | Resistor - 1K Ohm 0.25W | Digikey | 1.0KQBK-ND | 2 |
| Booster | R7 | Resistor - 0.47 Ohm 5W | Digikey | 0.47W-5-ND | 1 |
| Booster | IC1 | Op Amp - LF351 | Digikey | 497-2966-5-ND | 1 |
| Booster | Q1 | Transistor - NPN BC337OS | Digikey | BC337-ND | 1 |
| Booster | Q2 | Transistor - PNP BC327OS | Digikey | BC327-ND | 1 |
| Booster | Q3 | Transistor - PNP TIP126OS | Digikey | 497-2570-5-ND | 1 |
| Booster | Q4 | Transistor - NPN TIP121OS | Digikey | 497-2537-5-ND | 1 |
| Booster | C1 | Capacitor - 0.047uF | Digikey | P4307-ND | 1 |
| Case | | Project Case | Radio Shack | 270-1809 | 1 |
| Case | | Illuminated Rocker Switch | Radio Shack | 275-692 | 1 |
| Case | | 9 Pos. Male D-Sub Connector | Radio Shack | 276-1537 | 2 |
| Case | | Banana Jack Ins. Binding Posts | Radio Shack | 274-662 | 1 |
| Case | | Stackable Banana Plug | Radio Shack | 274-0734 | 1 |
| Case | | Transformer 115VAC 12.6VCT 6A | Digikey | HM5220ND | 1 |
Testing
Prior to using the board on your expensive locomotives, here are some simple tests to ensure the boards are working properly. Please be sure to use safety glasses and gloves for your protection in case of failure.
Power Supply
Using a Voltmeter, measure the DC voltage from the outputs of the 15V, 5V, and -15V terminals.
Booster
Connect the serial input on the Booster board to the 5V terminal, then connect the Booster to the power supply, measure the output, it should be a solid 15V or -15V (depends upon how your have your voltmeter hooked up to the terminals). Then connect the serial input on the Booster board to the Ground terminal (GND), the output should be the opposite of what you read previously.
