Construction
I injection mold the target faces and lamp holder on my own injection molding machine. On the left is the LED holder which I also injection mold from ABS plastic. This holds the super bright 10mm LEDs at a set distance behind the lenses for best effect.
They are both molded from black, UV-resistant ABS plastic making them very durable. They are perfect for locations where the signal might get hit by track crews, bystanders, etc. – in other words everywhere.
Between the target and the LED holder are the “Fresnel-like” lenses that I CNC machine from clear acrylic plastic rod. The lenses are designed to look like prototypical Fresnel lenses. They disperse the beam and eliminate the harshness of a bare LEDs.
The LEDs are mounted on a printed circuit board that contains the appropriate current limiting resistors for the desired operating voltage (12vdc is standard, specify voltage when you place your order).
The LED board has a four pin terminal block with screw terminals to connect the head to field wiring.
Full signal head ready to be mounted in a standard 1/2″ metal, or PVC, conduit box.
The conduit boxes are available at stores like Lowe’s and Home Depot in the USA. Contact me if they are not available in your area.
The heads are shipped without a conduit box because the appropriate box is determined by your mounting requirements (mast, signal bridge, etc.), head configuration (single, double, etc.), etc. You can purchase them for the same price I can. Once you start thinking about it, there are hundreds of different mounting configurations.
I have run across two major suppliers of PVC conduit boxes, Carlon and Cantex. I prefer the ones from Cantex because they have rounded ends which look more prototypical than the square ends that Carlon uses.
The boxes are usually available in PVC plastic and cast metal. The PVC models come with slip fittings to accept 1/2″ PVC conduit. The metal ones come with threaded fittings which will accept 1/2″ NPT for threaded pipe as well as standard threaded conduit fittings.
In some cases (signal bridges, etc.) you might also use the flexible conduit (PVC & metal).
In the future, if enough customers request it, I am considering injection molding a more detailed, prototypical housing that would also eliminate the two screws on the front currently required to secure the target/lamp assembly in the conduit box. Let me know if you are interested in this option.
Conduit Boxes
PVC boxes with slip joints are shown but all are available as metal boxes with 1/2″ NPT threaded openings.
Type “LB”
This is used to mount a single, three lamp, head. You can either plug the rear opening, or saw it off flush with the back and fill it with epoxy, two-part resin, etc. (shown on the right).
Type “E”
This box is harder to find but its the easiest to use because you don’t have to modify it as when using an “LB” box to mount a single head.
Type “C”
This box is used when you want to mount multiple heads on a single mast. You can also use it for a single head by plugging the top opening.
type “SLB”
This box is used for the two lamp heads. Unfortunately, as far as I know, this is the only “S” (for “short”) type box readily available. As far as I can tell, it is not available in PVC. If you find an “SE” box (no port on the back) let me know as I have never found one.
Options
All heads have the following LED board options (please specify at the time of order):
- An operating voltage other than the standard 12vdc (from about 3vdc on up).
- Added surge/lightning protection. This will help protect the LEDs from lightning strikes in the area but they will not protect against a direct strike that actually hits the cable, head, etc. This is typically not needed when using my signal controllers because the wire runs from the controller are short and the controller has surge protection on all the LED drive lines.
- Different connection for field wiring. By default the LED board is shipped with screw terminals. I can supply different connection types such as 4-pin plug, solder connection, etc.
Specific Products
Three Lamp Assembly (Part # SH-301-12)
3″ x 6″, ABS, 5/8″ lamp openings on 1″ centers, complete, ready to mount in box. (Note: Photo shows the original prototype circuit board, not the current production version)
Three Lamp Assembly (Part # SH-302-12)
4.352″ x 2″, ABS, 5/8″ lamp openings on 1″ centers, complete, ready to mount in box. (Note: This is the same as SH-301-xx but with smaller target)
Two Lamp Assembly (Part # SH-201)
1.375″ x 2.875″, ABS, 10mm lamp openings on 1″ centers, complete, ready to mount in box, soldered wire connections, 12vdc, no surge protection, green over red standard. Other colors, voltages, surge protection, etc. available as options. I can also supply this with a plug or screw terminals if desired.
This assembly does not have lenses or an LED holder. I machine the face of the 10mm LEDs flat to soften the harshness of the LED beam and widen the viewing angle.
A common use of this assembly is for a double-sided switch dwarf. This is easily made by machining the back off of two SLB boxes and epoxying them back-to-back as shown above.
Please contact me if you would like a two lamp head that uses the same lens openings (5/8″), Fresnel lenses, etc. as in the three lamp head.
(Limited availability, contact me prior to ordering)
Three Lamp Sub-assembly (Part # SH-303)
3″ x 6″, ABS, 5/8″ lamp openings on 1″ centers, includes target, lenses and LED holder. The holes in the rear of the LED holder are designed to accept 10mm LEDs. If you would like to use incandescent bulbs instead of LEDs this is a good place to start. You can easily machine the rear of the LED holder to accept a colored ‘gel’ and a lamp socket.
Three Lamp Target (Part # SH-304)
3″ x 6″, ABS, 5/8″ lamp openings on 1″ centers. This is a target only, no LED holder, no LEDs, no lenses, etc., just the target with the lamp hoods.
Three Lamp Target (Part # SH-305)
4.352″ x 2″, ABS, 5/8″ lamp openings on 1″ centers. This is the same as SH-304 but with smaller target.
Three Lamp Target (Part # SH-306)
3″ x 6″, Molded from two-part resin rather than ABS plastic, 5/8″ lamp openings on 1″ centers. This is a target only, no lamps, lenses, etc. These are the same as the SH-304 targets except that they are molded from two part resin. (See note below on resin. Limited availability, contact me prior to ordering)
Three Lamp Target (Part # SH-307)
4.352″ x 2″, Molded from two-part resin rather than ABS plastic, 5/8″ lamp openings on 1″ centers. These are the same as the SH-306 targets except that they have a smaller target. (See note below on resin. Limited availability, contact me prior to ordering)
Two Lamp Target (Part # SH-201)
1.375″ x 2.875″, Molded from two-part resin rather than ABS plastic, 5/8″ lamp openings on 1″ centers. This is a target only, no lamps, lenses, etc. The openings in this target are designed to accept my Fresnel-like lenses (see below). (See note below on resin. Limited availability, contact me prior to ordering)
Two Lamp Target (Part # SH-202)
1.375″ x 2.875″, Molded from two-part resin rather than ABS plastic, 10mm lamp openings on 1″ centers. This is the same as SH-201 except the openings are designed to accept 10mm LEDs. (See note below on resin. Limited availability, contact me prior to ordering)
Fresnel Lenses (Part # SH-001)
These lenses are CNC machined from acrylic plastic rod. They are designed to press into the targets that have 5/8″ holes. They do not have true Fresnel geometry but they are designed to look like prototypical Fresnel lenses. They serve to widen the beam viewing angle and eliminate the harshness of a bare LED beam.
Note on the resin assemblies
I have have a limited number of heads and targets that are molded from two-part resin as opposed to ABS. Dimension-ally they are the same as their ABS counterpart. They are perfectly serviceable but they are not quite as durable as the ABS parts. They are not ‘fragile’ but they will break if bent or struck with a hard object.