IndianaRog and the Temple of Steam

Although I have a few of these generators sprinkled throughout this website, I thought I would create a separate section for them as they seem to be growing in numbers and are a very nice accessory for any steam engine with enough power to drive them. 

First, a family photo so to speak, then we'll touch on each one separately:

In the lower left is the oldest generator/dynamo in the group.  As best I can determine it is a Bowman #839 AC dynamo built by Doll et Cie in approx. 1927.  It was a common practice at the time for one mfg. to specialize in a component and sell it to others. 

Supposedly Doll sold the black dynamo components to Bowman.  Bowman then  mounted them on the Meccano base and sold the dynamo as their own.  It has a small plaque stating 2 volts, 0.1 amps and lights quite nicely 80 years later.  A thin blue pinstripe outlines the horseshoe magnet while a thin black pinstripe adorns the red base.

The dark blue generator positioned above the Bowman is a Jensen Model 15 cast iron base model which utilized a 3 part magnet.  This 3 part magnet design replaced two earlier versions, the horseshoe shaped magnet used from the early '30's until 1950 and the one piece magnet version used for just the single year 1951.

I also have an early horseshoe magnet generator in a standalone version, it can be seen as part of my Jensen #20 Big Power Plant.

The same goes for the round magnet design from the single year 1951.   See my Jensen #10 from that year for an example of that type of magnet.

The 3 piece magnet design debuted in 1952 and has been in use by Jensen to this day (albeit with a change to the base which we'll cover in a bit). 

The Jensen 15's put out 2-3 volts AC and require a fairly high rate of spin to perform well, but they are the most robust generators out there intended for the toy steam market. 

The cast iron based versions pop up on eBay from time to time and are always snapped up quickly as they are favorites with collectors. 

In the 1980's Jensen painted the cast iron bases a teal blue-green color for the last few years they maintained the cast iron version. 

The cast iron base was replaced in the mid '80's by a formed aluminum base as seen in the next two generator examples. 

The lighter blue generator in the top center of the "family photo" and directly below is a Jensen 15BL AC model offered from 1995-2005.  This one featured ball bearings in the journal uprights as well as a pair of 3 step pulleys offering in effect a built in line shaft.  

The base of the 15BL was made from a heavy aluminum stamping that replaced the earlier cast iron type. 

Though not as elegant as cast iron, the aluminum base design is actually a better electrical conducting "gen-set" and better light output is possible for the same rpms.

Another improvement visible in this example is a pair of electrical contact tabs...one for positive and one for negative.  The previous, cast iron design depended on the frame to carry the negative which was less efficient than this arrangement.

Jensen only kept this design in their lineup for 10 years as it was apparently difficult to assemble and align the bearings which can be seen inside the journals in the second picture.

The third Jensen 15 seen in the upper right of the "family photo" above and directly below, has been in the Jensen lineup continously from the mid 1980's to present.   It features a natural aluminum pressed type base, dual electrical pickups and a single step pulley.

This model is what is currently available from Jensen and toy steam retailers and it still sets the standard for a reasonably priced AC toy steam generator and lamp combination.

All three of the Jensen generators shown feature the nickel plated brass lamp post and belled light fixture which has been in continous use since the mid 1930's...some things just can't be improved on!!

The last generator/lamp combination in the lower right of the "family photo" and below, is a concoction built by me.  The heart of this unit is a stepper motor, which can often be found residing in old dot matrix computers.  When recycled as I have done, the stepper motor becomes a dandy DC generator (my only DC example).

Within the wooden base I have concealed the wiring and other components which ultimately connect to a spare Jensen lamp post.   The lamp used is a 6 volt version and engines cannot be run full tilt connected to this as the stepper motor is capable of more than 20 volts DC...6 volt bulbs prefer a little less!

I give full credit for the stepper motor concept to a gentleman named Peter Santa Maria who sells them as ready to run units on eBay from time to time under seller name "PSANTAMA".  I incorporated one of his turnkey kits into my Jensen 51 replica as a DC power source and highly recommend them to others who want a high output DC generator, but don't care to scrounge for the parts. 

Peter maintains a website where you can buy several versions of his generators made up and ready to run...here's his website:  modelenginegenerators .  I highly recommend his offerings and he's a real gentleman to deal with.

All of the examples above work beautifully.   All AC generators use a #14 bulb available from Radio Shack.  My one DC example uses a #502 bulb available from www.bulbster.com.