I wasn't impressed with the performance with series wiring, so I never tried it again either.
@Norm Charbonneau posted:I’ve been running my MTH Centipedes with a single unmodded Cruise Commander for a few years now no prob.
Norm that is good news. My brother runs my trains more than I do and he can be a little heavy handed. I build them he wrecks them. I have some 10A 400v bridges and think I will do a breakout like John's. j
@JohnActon posted:Then I ran across an article on the web where the writer was discussing this very topic and his conclusion was what I had decided from my experiment. I was trying to find that article tonight but before I did I ran across a related discussion about automobile radiators Aluminum vs Copper. https://www.researchgate.net/p..._aluminium_or_copper Read about 1/3 down the page and look for the name Ammar Eqbal, Indian Institute of Technology Patna where he says the best heatsinks are a composite with a copper base and aluminum fins. I am glad I did the test but to my way of thinking it was a draw. j
Hi John,
My experience was the exact opposite. The application was high power IR diode lasers for a medical product. My choices for heat sinks were: copper base with graphite fins, all aluminum heat sink, and aluminum base with copper fins. The aluminum base with copper fins was the best choice [for this application]. Please note that the heat sink grease was silver filled and a high speed ducted fan cooled the fins. Lasers have the nasty habit of thermal runaway when they reach 80~85C. At a grand a copy I had to get it right.
If you have an interest in copper heat sinks just Google: Cool Innovations Thermal Systems.
To circle back to the original intent of the question: yes small heat sinks will help and they can be attached using at least two different ways mentioned in this thread.
Lou N
@Lou N posted:Hi John,
My experience was the exact opposite. The application was high power IR diode lasers for a medical product. My choices for heat sinks were: copper base with graphite fins, all aluminum heat sink, and aluminum base with copper fins. The aluminum base with copper fins was the best choice [for this application]. Please note that the heat sink grease was silver filled and a high speed ducted fan cooled the fins. Lasers have the nasty habit of thermal runaway when they reach 80~85C. At a grand a copy I had to get it right.
If you have an interest in copper heat sinks just Google: Cool Innovations Thermal Systems.
To circle back to the original intent of the question: yes small heat sinks will help and they can be attached using at least two different ways mentioned in this thread.
Lou N
Lou, I think your experience leads me to the conclusion that I was not taxing either the copper or the aluminum sink to the point that it mattered. Which may be the case in most of our toy train exploits. I do have some experience using liquid cooling with a copper radiator on a gaming computer I built several years ago. My nephew returned the box when it became obsolete for gaming and I am using it for streaming 4k video now. Think I used Thermal Grizzly compound on the processor. That box always runs cool. "Cool Innovations" Them some really purdy copper sinks. Always amazes me how beautiful technology can be. j
@Ron_S posted:@Norton Pete, I have a bunch of projects under way so I will finish upgrading a friends camelback and a set of B units with sound have on a back burner until hear your results.
Thanks, Ron
Ron, had a chance to run my K-Line UP ABAs today pulling 21 cars half scale milk cars, half MTH 18” heavyweights. We determined with the lighted passenger cars plus engine roof fans and lights in the engines the quiescent current was 2.6 amps. Running the engine, the Z4000 was reading about 6 amps +/- .5 amps. When the train had completed a 180 degree turn on 112” diameter track the 5 amp fuse blew. The fuse is only in the motor line, not track power to the boards. Not sure if it was a momentary increase in the load or something else. I didn’t get a chance to investigate further but may have more time in few weeks when we are not doing a show.
Anyway, the jury is out. I won’t be able to determine if the Cruise M is still OK for a few more days.
Pretty sure a Cruise Commander driving 4 motors may be OK, not sure about a Cruise M driving 6 motors.
Pete
@Norton Thanks Pete.
The only Odyssey engine I might put a M in will be a BN U33 that is going wonky on me. Everything else is pre Legacy and mostly orphan units made from spare parts and being upgraded to CC, mostly F3 and E7 ABA which would have the Railsounds in the B and each A unit powered.
I have upgraded a few GP38-2's and a Proto1 E8 RK AA with CC but they typically run with a MU right now, what interests me is making the Rio Grande AA, NP ABA, TCA ABA F3 and GS E7 AB and SP&S F7 ABA all tethered units to improve response to throttle and save on CC in each powered unit.
I am patient and will start on my 4-8-4 upgrades to bring from Proto 1 to CC, CG,SC Large Steam RS.
Ron, I had chance to check out my 6 motor K-Line E8s to try and determine why the fuse blew. Part of the problem was wires rubbing on the flywheels. Both A units are fairly full with wires for lights, sound and roof fan power. Current running light went from 4.2 amps to 1.6 total while running after securing the wires away from the flywheels. About .6 amps of these 1.6 are used for fans and lights.
Conclusion. Look for something causing a drag on the motors if you are seeing high current draws.
Pete
That is good to hear Pete!
I got in a bunch of BR84 rectifiers, and just sent a pair of defunct CC to GRJ to see if he can resurrect them. If he can, they will become my tethered candidates.
I have the classification lights, LED cab light and LED headlight in each shell. The wiring is done and once I get a tethered CC, I will be testing out my project.
I am looking forward to track testing when I get that far. Endless possibilities if this works.
GRJ is correct that the outside temperature of the bridge package should be roughly the same for 8A, 10A and 12A bridges with the similar package since they will dissipate the same amount of power. There is a temperature gradient inside the package from the edges to the devices. The bridge devices are hotter than the outside of the package. Assuming that the 10A and 12A bridges are manufactured with larger devices than the 8A bridges the power density in these devices will be less. The lower power density generally results in a lower device temperature resulting in less leakage. The temperature of the devices is very dependent on their physical layout. The effect might be small but there should be a slight advantage using the larger ampere bridges.
Carl
