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Offline Moritz-BR365  
#1 Posted : 06 August 2019 15:04:41(UTC)

Joined: 02/04/2013(UTC)
Posts: 677
I got an quite nice version of an E 95 locomotive. It is the E 95 01 from Brawa, not the new released model but the Premium-Model #0241, produced from 1999 until 2005.


Main differences to the new version:
- 8-pole NEM 652 DSS
- two open 5-pole motors
- head light with micro bulbs
- not ready for sound

In the E 95 is surprisingly little space! Unfortunately, because the case is made of plastic, but very finely detailed, Brawa has used the space for a heavy zinc die-cast chassis. Only at the top there is room for a switch or a decoder. Here also the loudspeaker must find place.


I chose a small, space-saving MTC21 adapter board from Doehler&Haass. The speaker is a LS1511, which I buy at https://www.austromodell.at. Also, the sound capsule used comes from there.

To add some space, I unsoldered the power transistor and positioned it in front of the board instead of under the board. So everything finds room, albeit scarcely:



The decoder is diagonally upside down on double-sided assembly tape law. Essentially, the decoder socket sticks to the mounting tape. The speaker is positioned over it, where it sticks to the side of the mounting tape and is protected up against contact kit of the board through the connection cable. Forward and sideways, the plastic housing will hold everything in place.

The sound decoder is a Doehler&Haass SD21A-4, Brawa's new generation E95 uses a Doehler&Haass SD22A-4, the PluX22 version. Therefore, there is also a nice sound project for the E 95, which was created by the Austrian soundmaker LeoSoundLab.

In the video you can see that the single driven axle starts moving much earlier than the three right drive axles. My hope that this makes less noticeable while driving, has unfortunately not met. Therefore, I have rebuilt the locomotive again.

In the front locomotive I have removed the engine, as well as the screw from the gearbox. The drive axle with traction tires I have exchanged with the first axle of the second locomotive half. In place of the engine in the front locomotive, I have installed an additional, larger speaker parallel to the small one.

Here the engine is already developed. In order for the drive axle to rotate freely, the worm must still be removed, which is held by a small plastic cage.




Buffer Capacitor
By eliminating the second engine, it makes sense to use the space. Accordingly, I made the front half of the locomotive again, to install an capacitor buffer package.

The basic circuit consists of a charging resistor, a Schottky diode and an Elko, which are connected together as shown and connected to decoder plus (U +) and decoder minus (GND).


Since the free space is quite large, I had chosen only a 3.300μF Elko:


What I had not considered that in the front just the NEM652 interface stretches their contacts down and so the motherboard no longer fits on the frame. So I took two 1,000μF electrolytic capacitors in parallel, they build a bit shorter and fit next to each other in the loco:


Note: For Elkos applies in the parallel circuit, the capacity adds up, the dielectric strength remains the same. When connected in series, the total capacity is calculated as in a parallel connection of resistors!

Decoder-Minus (GND) is not brought out to the NEM652 interface, but it is connected to a solder point of the Doehler & Haass MTC21 adapter board. There I have soldered the brown cable, which leads to the minus pole of the Elko package.

Decoder-Plus (U +) can be tapped on the motherboard because U + is connected to the NEM652 interface. The easiest way U + can be tapped at the top of the big diode as shown in the following picture (orange cable):


Everything assembled then looks like this and small voltage drops are reliably buffered, even if the capacity is not as effective as a PowerPack, as is the case with Esu, Doehler & Haas or Märklin. But the price of this small solution with about 2 € material costs is also significantly lower than the PowerPacks, which are available from about 40 €.


Here is a short demo of how the sound is buffered if you briefly interrupt the voltage:

thanks 6 users liked this useful post by Moritz-BR365
Offline franciscohg  
#2 Posted : 06 August 2019 19:54:06(UTC)

Joined: 10/07/2002(UTC)
Posts: 3,165
Location: Patagonia
Hello Moritz
Great work as usual.
it is interesting to know that the two motors does not start at the same time. It is the same with mine, newer version with a D&H sound decoder already equipped. As you could remember i had serious running issues wich lead me to install a D&H power pack on it. It was not easy since the only available space was in the dummy unit were an extra weight had to be removed.
For your homemade solution wich are the values you used for the resistor and schottky diode?
UserPostedImage German trains era I-II and selected III, era depends on the mood, mostly Maerklin but i can be heretic if needed XD, heresy is no longer an issue.. LOL
thanks 1 user liked this useful post by franciscohg
Offline Moritz-BR365  
#3 Posted : 06 August 2019 20:41:53(UTC)

Joined: 02/04/2013(UTC)
Posts: 677
Hello Francis,
yes, I remember your conversion, you made great video of it. It is really bad, when the two motors are not identical in their behaviour.
I guess, the main problem is the gear, which doesn't allow to move the motor from the wheels, other than with the standard Märklin HLA Motors.

Die the power pack I use usually a 100 ohm resistor, a Schottky Diode with 2A current and capacity what fits into the available space.

thanks 1 user liked this useful post by Moritz-BR365
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