Stu Dom oversees rewiring on Proto2000 engines.
The club has begun a clinic night in place of one of the business meetings each month. Club members are encourage to give a clinic about an area of expertise or interest. The first clinic of 2012 was presented by Stu Dom on the evening of January 22, 2012, about rewiring Proto2000 engines. Below is a short summary of his clinic along with background documents with more drawings and information.
When the first Proto 2000 (Life-Like) engines came onto the scene, I raced out to buy everything I could in my preferred railroad (PRR), and there was plenty from which to choose. The engines were extremely detailed, looked better than almost anything I’d seen before, and ran well.
However, this delight soon subsided when I found that the engines ran much more slowly (perhaps prototypical) than the breed of engines most club members had (Atlas, Athearn & some Stewart). However, many times these engines were not put on the mainline, because they would get overtaken by the majority of the trains. There were many words from other club members about these obstacles on the track, more than a handful of rear-enders, and I would reluctantly take these beautiful “beasts” off of the track and run my other engines.
I really wanted to run these engines, and began to look into the cause for this uncommon behavior. The first thing I noticed was that these engines came equipped with constant intensity directional lighting – which appeared to be relatively new to the off-the-shelf stable of engines. My original Stewart F units had very bright lights but I don’t believe they were “Constant Intensity” lights. Having some electrical background, I decided to take a further look into these engines to determine if this could be the cause of this phenomena, understand why this was the
case, and to develop a corrective fix. I initiated my first efforts on a pair of SD-9 engines that I had, and later moved onto SD-7, GP-7 & GP-9 engines.
In all cases, I found that the constant intensity lighting circuit introduces a resistance or voltage drop in series with the motor. This means that for a given track voltage, the actual voltage getting to the motor was up to about 2.5 to 2.8 volts less, which translates to about a 20% reduction at full power. The power that a motor is able to produce is directly dependent on the current in the motor, and Ohms Law would indicate that this current is also directly related to the voltage across the motor, so the motor was receiving less current than other engines. To correct the problem, I developed the circuit (shown in the PDF at the bottom of the page) which allows the engine to operate at speeds consistent with other manufactures products.-Stu Dom
The attached PDF includes step by step instructions on how this type of modification can be made to a Proto2000 locomotive.
Download the PDF by clicking here.
