A $2:00 fix to read Tsunami CVs on the Program Track with NCE PHP.

The Main North HOME

Thanks to Mark Loos, Barry Chinn and Mark Gurries.

 

Just recently I installed a Soundtraxx Tsunami into an Austrains 36 steam loco. I could not read CVs on the Program Track. As I am used to programming on the main POM, I was not unduly worried by this inability to read CVs. Programming on the Main with NCE with the new Eprom allows you to change ALL CVs including CV 1 the short 2 digit address. As stated in the Tsunami User Manual and at the Soundtraxx web site, Soundtraxx recommends Tsunami users will need to purchase the Soundtraxx Program Track Booster, PTB-100 to be able to read CVs.

 

I remembered about a modification of the early Power House Pro (see below) and this included adding an extra lamp. Maybe I could add another lamp to enable Tsunami CV value readings. The $2 fix to read Tsunami CVs is the addition of an extra 80 – 100 mA lamp ONLY. Easy to do and for the cost of a couple of dollars, well worth it considering a Soundtraxx PTB-100 costs US$59:95 (A$85:00). Now I can buy another Tsunami that has turned out to be a really great decoder. Even better, the A$85 went towards a new Power Cab from NCE that reads all sound loco CVs PLUS it’s a full entry level 1.7 amp DCC system providing all but a few of the features its big brother, the Procab. See Tony’s review for details of the Power Cab.  

 

Warning: This modification will void any warranty of the PHP. While this modification allowed me to reads CVs of the Tsunamis I take no responsibility of what impact this extra lamp has on the circuit of the PHP.

 

Some users of the early NCE Powerhouse Pro (pre about 2001) with the Loop/Normal switch on the front, had difficulty reading CVs on the Program Track when programming Soundtraxx and QSI sound equipped locos. Reading non sound decoders was not a problem. Mark Loos suggested replacing the 12 volt regulator with a 15 volt version and fitting an extra 14 volt 80 mA lamp. See below photo to identify. These units will need modification as per Mark Gurries’s article, see below.

 

Below are three photos to identify the Command Station/Boosters to determine the status of the circuit boards, that will determine if just adding the extra lamp will provide reading the Tsunami CVs.

 

 

 

 

 

Early POWERHOUSE Command Station/Booster with the Loop/Normal switch.

 

The upper Command Station circuit board removed, showing the lower circuit board with a REV D status.

 

Photo courtesy of Mark Loos.

 

Units with this board may need the 15 volt regulator upgrade as described in Mark Gurries’s article at the Files section of the Yahoo NCE group.

 

Select the Soundtraxx 15Vmod V2.pdf link.

 

NCE also offered to modify this command station/booster by what some called the Soundtraxx modification.

 

 

 

 

 

My Power Pro with the top circuit board of the Command Station removed showing the lower boards. The circuit board had etched 2002 and the “white” R/H sticker showing 013003. Underneath the sticker on the R/H side etched on the circuit board is “REV F”.

 

Shown are the two voltage regulators attached to the R/H rear case and the third voltage regulator, an MC7815 unit in the centre foreground in front of the 4 capacitors and the square bridge rectifier and has two 80 mAs lamps fitted.

 

I have not had any trouble reading sound loco CVs except the Soundtraxx Tsunami.

 

This unit does not require a voltage regulator replacement.

 

 

 

 

A close up of the circuit board, showing the 3 voltage regulators.

 

Top L/H – 7812, Top R/H 7805 and middle foreground the 7815.

 

Adjacent to screw under the 7805 voltage regulator on the top right is the REV F etched onto the circuit board. I had to remove the 013003 sticker.

 

On the left hand booster board is a sticker 021103. I guess these stickers represent board manufacture dates.

 

The long black receptacle between the two rear regulators is where the upper board plugs in.

 

Determine the revision status of the Lower Command Station circuit board. Circuit boards, “REV E” and on, do not require a voltage regulator replacement.

 

To read the Tsunami CVs on the Program Track, I have added a third lamp to the two already fitted. The lamp is a 12 volt 80 – 100 mAs purchased from an auto parts store. 

 

 

 

 

 

Remove the PHP lower circuit board as per Mark’s instructions in the above link.

 

View of the top of the lower circuit board of the PHP showing the two 80 mAs lamps and the receptacle for the power and program track connections.

 

 

 

 

 

Close up of the 80 mA lamps solder connections and program track/power receptacle.

 

When comparing these two photos, it can be seen that the two parallel lamps are connected in series with the power feed to the “program track” terminals.

 

Adding the extra lamp in parallel to the original two, increases the current to the program track. These lamps restrict the current, similar to what the 1156 auto lamps do in power district wiring.

 

I have soldered two leads acting as fly leads to extra lamp. I did this to experiment a little with different lamps.

 

A 90 mA lamp could be connected directly to these solder pads as Mark’s original article described to fit the second of the 80 mAs.

 

Fit circuit boards to the original position. 

 

 

 

The extra lamp with wires soldered to the “wire lead” contacts of this automotive “wedge” 12 volt 1.2 watt lamp. Black heat shrink to fit over connection to insulate lamp.

 

Part numbers:

Hella - W121.2

 

 

Available from auto electricians and car accessory shops etc.

 

Tests of the current draw of the lamp at:

12 volts is 84 mAs.

14 volts is 92 mAs

                   

 

 

 

The lamp installed and laying on the booster circuit board.

 

I installed a SPST switch to disconnect this extra lamp for all other programming. This keeps the original lower current for checking “initial” decoder installations.

 

The SPST switch is installed in the hole in the PHP chassis that was used on previous PHPs for the “Loop” switch.

 

I cut a hole in the facia with a sharp hobby knife (Exacto).

 

The switch can be left out, but I feel more comfortable switching out the extra lamp for non Tsunami programming.

 

Program track original current, 2 X 80 = 160 mAs. Mod - 160 + 92 = 252 mAs.

 

This works for me, but if it does not for you, add two extra 80 mAs lamps as Barry has done.

 

 

 

 

Below are the email messages on Yahoo Soundtraxx group from Barry Chinn and me discussing the extra lamps.

 

-----Original Message-----

From: soundtraxx@yahoogroups.com [mailto:soundtraxx@yahoogroups.com] On Behalf Of Barry Chinn

Sent: Saturday, 21 January 2006 5:08 AM

To: yahoo soundtraxx; Rwbrv4@aol.com

Subject: [soundtraxx] modifying NCE command station for QSI / Soundtraxx

 

Hello everyone.

 

I found the first set of instructions for 12V to 15V regulator that shows how to modify the NCE command station for the programming track.  (This applies ONLY to older units.  Later units from the factory came with the 15V regulator).

 

Thanks again to Mark Loos & Mark Gurries.  Just look at the files section of the NCE-DCC Yahoo group.  (hey, that's us?).  You may not be able to click this link directly, so go to the NCE-DCC group, then click on files --> circuits --> Soundtraxx15Vmod.pdf

 

 

http://groups.yahoo.com/group/NCE-DCC/files/Circuits%20and%20Stuff/

 

I am retyping the text only part of the instructions below:

 

NCE * 15V Regulator Upgrade

 

Remove the 4 screws holding the Power House Pro cover.  Remove the 2 stand-off screws from the 9 pin DIN connector on the front panel.  Remove the 2 screws on the top circuit board (toward the front panel).  Carefully lift the board out, unplugging it from the bottom board.

 

Remove the 2 standoffs (toward the front) on the bottom right hand side board.  Remove the 2 screws toward the back.  There are 2 regulators screwed to the back panel - remove the screw and nut on both.  The 12V MC7812C regulator is right behind the 4 large capacitors in the middle of the picture.  The best way to remove the regulator is to clip it out, and then use a solder sucker to clean out the holes.  Mount the new 15V MC7815 regulator and solder it in place.

 

Locate the current limit lamp toward the front of the board and solder another 14V, 80ma bulb in parallel (across) the existing bulb.  The easiest way to do this is to solder the new bulb on to the bottom of the circuit board.  Re-assemble everything and you're good to go!

 

(the above from Mark Loos & Mark Gurries?)

 

***** Additional lamps for QSI / Soundtraxx *****

 

Using additional wire, 2 more 14V 80ma bulbs and a DPDT toggle switch, I wired these in parallel with the modified additional bulb.  In the center off position, you have the normal programming configuration.  When the DPDT switch is thrown in the correct direction, the 2 add'l bulbs are placed in parallel with the other 2 bulbs, thus increasing the maximum current to the programming track.

 

If you are really bold (careless?) you can use the other position of the DPDT switch set up to BYPASS all maximum current protection.  USE AT YOUR OWN RISK, SIGNIFICANT DAMAGE COULD RESULT.  (I wired mine & SLHRS's that way though).

 

/s/ Barry Chinn

 

Hi Barry

 

I did add an extra 30 mA lamp to my already modified command station (extra lamp and 15 volt regulator) and it made no difference to trying to read CVs on my Tsunami. I could always read CVs on all my previous Soundtraxx decoders.

 

Are you saying, in total, FOUR 80 mA lamps that would give 320 mAs of programming current? Is this safe for the "chip" that controls the Program Track?

 

Have you installed these 4 lamps and are you able to read CVs on the Tsunami?

 

Thanks

 

Marcus

 

 

 

Hello Marcus.

 

Yes, I used a total of FOUR 80ma bulbs which totals 320ma.  It works just fine.  I also found that you absolutely must have the motor connected for the Tsunami to read properly on the programming track.  I'm thinking of deleting the bypass (no short protection with four bulbs, which would give a total of 480ma.  That's better than having no protection.

 

Anyway, try a total of four 80 ma bulbs (when circuit is cut in).  Let me (us) know how that works.

 

/s/ Barry Chinn