9V Extreme - first test results re inclinations and power supply

[Haddock51]

Hello Haddock,

Is it not easier (and cheaper) to buy four power supply units (with current limitation 5 Amps), and plug each of the 4 9V speed regulators?

Maybe, but for me this is history. If I had to decide again, I might consider.

[Lazarus]

Get 12v controlers I use them and they are fine just note on the controler where 9v is. These run at 8amps, I needed the amps for point motors and they also run alot smother when trains with lots of motors and load.

The 7864 transformer has three outputs:

- sec I: 0-12V DC (as noted by Bricktrix, the maximum voltage is actually 16,5V)

- sec II: 12V DC (also actually 16,5V)

- sec III: 13V AC

The maximum load for I is 8VA

The maximum load for II and III combined is 8VA

If you want more amps, you could take a look at transformer 740:

- sec I: 0-13V DC, 11VA

- sec II: 16V AC, 16VA

- sec III: 3,6V AC, 6VA

[Haddock51]

My first modified 9V speed control unit is now ready and tested.

These are the modifications:

Diodes D3, D4, D5 and D6 were replaced by 3A diodes. (See also picture in my first post dated 5 december 2013).

The LM317 has been removed and replaced by a LM350. (Soldering on the electric circuit was done by a specialist).

The LM350 is mounted on a heatsink with a thermal resistence of 3K/W@20W. https://www.elfa.se/...75-621-50&toc=0

The heatsink is mounted on an Epoxy laminate plate which sits on the backside of the box.

Since the 3A diodes will generate heat as well - up to 60/70 degrees Celsius in an almost hermetically sealed box - I mounted a 12VDC minifan (80 mA) on the outside of the box.

In order to stress-test this unit properly, I decided to add two more 9V engines to the Iron Ore Train which brings it up to eight engines in total.

The main purpose with this first test was to get answers on questions re heat increase and heatsink efficiency. Temperature outside the box was measured with a laser thermometer and inside the box with an outdoor thermometer. Room temperature was/is 20 degrees Celsius.

In order to generate as much W (VA) and heat in the LM350 as possible, I ran the train at very low speed initially. Unfortunately, this resulted in several derailments in the grades, most likely due to the length and weight of the train combined with unbalanced push/pull forces at low speed. Therefore I had to continue with medium speed for the rest of the test. This showed again how tricky it is to operate such long trains with so many engines, particularly uphill and downhill (without brakes...)

To summarize the test results:

LM350 temperature peaked at 75/80 degrees Celsius when operating at very low speed.Temperature on top of the heatsink peaked at 55 degrees. Temperature inside the box rose gradually and reached 37 degrees after approx. 30 minutes.

The test track is too short to test maximum speed over a longer distance. However, the engines responded remarkably when I went for full speed (which was expected given the fact that an LM350 provides 3A - which is twice as much compared to the LM317 - and sufficient for eight 9V engines that require approx. 350 mA each at most).

Personally, I am satisfied with these first test results re the modified 9V speed control unit. It means that I don't have to worry any more about current and heat when running large trains with many engines in the new display. I also recognize that this modified speed control unit is not suitable for children.

So now it's time to build three more modified units.

The only major topic that remains to be tested are the safety fences around the curves above floor level. Enough with electronics - and back to mechanics ...

Edited October 23, 2014 by Haddock51

[snowvictim]

One question, one recommendation:

Q: How many 9V motors are you running on the HE?

R: Flip the second 10020 round, it'll look better.

[Haddock51]

One question, one recommendation:

Q: How many 9V motors are you running on the HE?

R: Flip the second 10020 round, it'll look better.

My HE is extended with two coaches and runs on four 9V engines.

I used to have the second 10020 your way but a good friend of mine insisted in flipping it, with the same argument - it will look better....

So now, I will flip it back again ....

Edited October 22, 2014 by Haddock51

[peterab]

By the way, Peterab, don't forget to send me the pictures you promised me.

Sorry Haddock51,

I didn't get to open up our controllers and forgot to reply to this topic. It seems you've solved your power supply problems. I had not even thought about replacing the diodes which I assume are in the rectifier bridge, but it looks like you've got some good electronic advice at your end. Once you build your other three controllers you sound like you are ready to go. I must admit this project sounded a bit crazy at first but I look forward to seeing the result. It is still crazy, but in an exciting way now. Good luck.

[Haddock51]

That's ok peterab. You're right, I've really got some good electronic advice and help on my end.

There has been a lot of thinking around this topic during the past months. However the endresult seems to be quite ok.

Crazy project? Well yes but it helps you stay sane ...

Edited October 23, 2014 by Haddock51