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Modified Circuit 9
Parts List: 1-CMOS 4011 NAND IC/2N3904 transistor/4.7 mf capacitor/220 mf capacitor/120 ohm resistor/
100K ohm resistor/1K ohm resistor/470 ohm resistor
Radio Shack resistors: (100 ohms + 22 ohms) in series - can be used for the 120 ohm resistor.
Note: A trimmer may be incorporated in or used for *R to obtain the desired effect. The 2 resistors making up *R in
the above circuit were available at Radio Shack.
This circuit represents a realistic triangular waveform circuit. (Circuit 9 uses a square wave)
In designing the circuit, I made use of the 4011's capability as both an oscillator together with
it's ability to output a triangular type waveform to the NPN transistor powering the bulbs. This makes
for a good simulation of the 20585 Gyralite.
The input to this circuit is taken from the collector of the 2N3906 PNP transistor of circuit 9.
Using the components listed, a flash rate of 55-60 flashes per minutes was attained.
Because of the tolerence of the electrolytic capacitors incorporated in this circuit, the values of resistance
may have to be determined in order to get the desired effect together with the 55-60 flashes per minute rate.
A GP60 Athearn locomotive was used in this circuit. I mounted all circuitry in the boxcar. Jay-Bee metal wheels with wipers, etc. - were used for electrical activation from the boxcar wheels. The interior cab lighting bulb was eliminated. I also used a 1K resistor for the 47 ohm one of Circuit 9. This makes it possible to turn the circuit on with 3 volts track voltage. The resulting connection from the boxcar to the locomotive was 2 wires.
The circuit was put together on a Radio Shack circuit board, which was cut to accomodate the boxcar mounting. A socket is used for the IC. The metal tab was cut off the LM317 adjustable voltage regulator. The DB-9 connectors were used for ease of putting the 2 components together. Wires are soldered to the pins of the DB-9 plug and socket. Hot glue was used to coat wire at junctions with pins to act as a strain relief for the wires. This glue acts to combine the wires at the junction with both plug and socket. The 4700 mf capacitor is mounted as shown. The battery holders, circuit board and capacitor were all mounted using hot glue. Notches were made at the front base of the boxcar to accomodate the wires running to the locomotive. Hot glue is used for securing wire. It should be noted that the connectors could optionally be eliminated or other connectors could be used. One should keep the assembly as well as the disassembly of the boxcar in mind (batteries) as the circuit is constructed.
The DB-9 plug is inserted into the DB-9 socket. Wires between the boxcar and locomotive are checked for slack. As in Circuit 9, holes were drilled in the location on the locomotive for the air hoses. A drop of hot glue on the inside of these holes will secure the 2 wire from the boxcar, which supply the voltage for the 2 headlight bulbs (which are wired in series).
This is an option:
I used a diode bank (3 diodes soldered in series - keep direction of current in mind for proper polarity) for this locomotive. The "reverse" direction diode bank was eliminated. This locomotive would run in the forward direction. I wanted to have the light circuit operate while the locomotive was stopped.
The connector strip was removed, rotated 180°, and the excess strip on the front connector strip part was trimmed off. The rotation was done because of the interior geometry of this locomotive. The truck electrical transfer structures were soldered to the connecting strip.
A piece of brass was cut to be placed against the brush spring end. One end was soldered to the motor body (sand parts first). A piece of insulating material was placed between the brass and the metal clip that previously held the brush spring. This metal clip was then secured in its former position, securing the brass strip and insulating material between them. The connecting clip was secured to the metal clip.
One end of the diode bank was soldered to motor body while the other was soldered to the connecting strip.
The ends of the connecting strip ride on truck electical transfer structures as shown.
The "Details West" 20585 Gyralite plate was not used in this circuit. It is an option.
