Assembly:

 

First open the parts kit and check that each part is present. If not notify RR-CirKits and we will send a replacement.

 

Start out by installing the resistors. Bend each resistor lead at a 90 degree angle close to the ends of the resistor body. After inserting each resistor into the board, bend the leads at about a 30-45 degree angle away from the resistor body, and clip them off about 1/16" from the solder pad. You may either solder each one as you install it, or solder a group of several at one time. When soldering remember that if it takes more than 2-3 seconds to complete each joint there is some problem. Be sure to use a well tinned iron with a clean tip. Too small an iron can cause as much heat damage as too large an iron because it will take too long to heat each joint and flow the solder. Likewise, too much solder causes more problems than too little, as it increases the likelihood of bridging between adjacent pads. However, be sure to use sufficient solder to assure that a fillet of solder forms between the circuit pads and the component leads. Resistors may be oriented in either direction. Facing them as shown in the parts drawing will make it easier to read the colors when you double check their values. Up, down, etc., refer to board when placed in the same orientation as shown in the parts pictorial diagram.

 

 

 

 

 

 

Select your desired crossbuck flasher lamp options before adding these next parts, and then choose just one out of the following three sections.

 

This is the default choice. The LED "soft start" emulation only works properly in this configuration. For common anode wired LEDs. (Two transistors and two 1K ohm resistors will remain unused):

 

For common cathode wired LEDs. (Two transistors and two 1K ohm resistors will remain unused):

 

For incandescent lamps. (Two 330 ohm resistors will remain unused):

 

Now install the power diode

 

Next install all the logic diodes. Note that there is no common orientation for these parts, however polarity is important. Check each one carefully to match the silkscreen printing on the circuit card.

 

 

Now install the headers, Terminals, and sockets. The slots in the polarized 10 pin headers both face to the right.

 

 

Next install the bypass and coupling capacitors. These capacitors are not polarity sensitive, and may be installed in either direction.

 

Now install the filter and timing capacitors. These capacitors are polarity sensitive, and in the case of C1 could possibly cause a hazard if installed incorrectly. All polarity sensitive capacitors have their + terminal facing the upper edge of the board except for C16 which faces left. Some may be marked with a negative band, and others with a small plus (+) sign.

 

Now install the remaining components.

 

At this point you should test the power supply voltages. Connect your power source (10-15V AC or DC) to the input terminal strip and measure the voltage between pin 2 and pin 6 of U4. It should measure 5VDC. (Pin 1 is the square pad, and the IC leads count down the left side and back up the right side.) Note that if you are using DC, then the negative lead is closest to C1. Reversing the power leads will not harm the board, but it will not work. After the test, remove power from the board.

 

 

Now install the integrated circuits. The notched end of all the ICs face the upper edge of the board. It may help to pre-form the IC leads to fit the circuit board hole spacing.

 

This should conclude all the required soldering. Check over all your connections to be sure that there are no bridged connections, and that each one has a fully formed fillet of solder between the circuit pad and the component lead.

 

Now choose the proper jumper options for your prototype gate operation.

 

 

There are some other possibilities such as ringing for 20 seconds or until the train enters the crossing, which ever occurs first. (J8 and J4) These various options should allow you to simulate most prototypical conditions. Note that fixed timed ringing will be overridden if the train clears the approach block or the crossing in less time than set by the jumper.