troller throttle

Model Railroader General Discussion (Model Railroader)
1

i have a troller throttle 2.5 that i am trying to identify the solid state 3 pin device mounted to a heat sink. it has no part number on it and aside from the ac to dc conversion portion appears to be the only solid state device. the throttle control is in the wide open mode. this is possible a darlington transistor. if someone knows what this is or could make a replacement recommendation i would be grateful.

jon in tennessee

2

Jon;

It is a power darlington. This guy probably knows: http://www.geocities.com/budb3/index.html scroll down aways and you’ll see an e-mail link.

One of these (NPN): http://www.digikey.com/scripts/DkSearch/dksus.dll?Filter

OR one of these (PNP): http://www.digikey.com/scripts/DkSearch/dksus.dll?Filter

should work fine, depending on how the pack is wired. If you pick the wrong one, it will probably blow instantly.

3

thanks for the info. i will check it out.

jon

4

Lets see if I understand. When you turn the power on it is full power and does not repspond to the power control knob? I unpacked some stuff from the attic this weekend, and came a cross a Troller that I got …20 years ago. I plugged it in to see if it still worked and that is what happened. Full power only…let me know how it goes.If I can fix it I will.

5

i found the answer in one of peter thorne’s books. the defective part is a TIP120 that is cheap and easily found.

jon in tennessee

6

Here is a source: http://www.digikey.com/scripts/DkSearch/dksus.dll?KeywordSearch with several in stock [:D] (make that several thousand).

You should consider improving the heat sink. as BUBD mentions.

7

By the way ===somewhere deep in my memory is the recollection that Troller had a hard time getting UL approval for their throttles. I do remember them being sold at give-away prices when Troller left the business.
Dave Nelson

8

When I saw the subject I thought you were talking about fishing and got my pole and tackle box. [:D]

9

IIRC, one of the reasons Troller went out of business was that their power packs acquired a reputation for burning out motors, especially the weak N scale motors of the era, because of some issue with the autopulse feature. There were some articles on the subject in Model Railroader in the mid-1980s.