I recently purchased the Bachmann 2-4-4-2 articulated locomotive which I am extremely pleased with. I only operate using a DC power pack (Railpower 1300), your included info sheet states that if both front and rear lights flash to shut down the throttle immediately. This is happening to me, but now but the engine will not recover. What is the next step?
I assume that you have not got a DCC system?
If you have or perhaps know someone who has, try a decoder reset ( that is usually the first action with decoder problems) reset enter value 8 in CV8.
If you have no access to a digital system I would try removing the decoder from its socket in the tender, and fitting the blanking plug which should have been supplied with the loco in one of the plastic bags.
Just in case you are familiar with a blanking plug it is a small pC type board aboud 30mm X 20mm which directly peplaces the decoder. The decoder is accessable under the tender fuel load.
Hey thanks so much for the information.
The guy at the service desk said the same thing about the blanking plug. I searched through the extra parts bag but it wasn't to be found. I ended up sending in the loco yesterday. The data sheet said that there could be problems if the power source exceeded 21 volts. My powerpack has an output max of 15 volts so I'm safe there (as I discovered after I sent off my first post). I'll keep you updated when I hear anything.
If you're running on DC I would suggest NOT using "pulse power" as that will fry PC Boards and DCC/Sound components as well. Some MRC power packs are equipped with that for DC users. Before DCC became a household name, Pulse power was able to keep engines running smoother without too much hiccups save for dirty track. But now it's become obsolete and rather a nuisance for those who wouldn't know.
The MRC Railpower 1300 does not have the "pulse" feature. The MRC power packs that have the pulse feature, have a slide switch designated and clearly marked for it. The only slide switches the 1300 has is for direction and on/off.
Thanks for the FYI guys. I'm looking forward to getting my engine back though it maybe another 3-4 weeks, will keep you posted. I appreciate the help the forum has been giving me.
J
Alright... Its been a while since I sent off my model and had it returned. Bachmann said that there was nothing wrong with it. Bummed out, it sat on my shelf for quite a while until recently when I removed the decoder and rewired everything. To my surprise the locomotive runs exceptionally well, low speed is better than expected.
Just one concern, headlight and tender lights are LED. I'm aware that a resister or diode needs to be placed in line with them but I don't know the type or value. Any suggestions?
J
I use 1/2 Watt, Carbon Film Resistors that I have bought from Radio Shack for 5mm LEDs in HO loco projects. I have used 680 OHM ones and the LED is still what I would call on the bright side. You can either use a greater OHM resistor to dull it down or put more than one resistor together in series to increase the number of OHMs, to where you want the brightness.
Quote from: Jeffrey_L on January 29, 2015, 10:07:35 AM
Alright... Its been a while since I sent off my model and had it returned. Bachmann said that there was nothing wrong with it. Bummed out, it sat on my shelf for quite a while until recently when I removed the decoder and rewired everything. To my surprise the locomotive runs exceptionally well, low speed is better than expected.
Just one concern, headlight and tender lights are LED. I'm aware that a resister or diode needs to be placed in line with them but I don't know the type or value. Any suggestions?
J
You said you rewired it. Hopefully you did not connect the LED's to the decoder.
Rich
I know better, that's why I asked if anyone knew what the proper resister was. I have a decoder on order for a 2 truck shay so if this is successful, I'll be ordering another. I know, I'm still on a steep learning curve and having fun.
Quote from: Jeffrey_L on February 08, 2015, 11:08:15 AM
I know better, that's why I asked if anyone knew what the proper resister was. I have a decoder on order for a 2 truck shay so if this is successful, I'll be ordering another. I know, I'm still on a steep learning curve and having fun.
ok as not sure.
Rich
Since you are new to DCC, look through the below link on lighting.
look at all his site. He has loads of info on DCC.
http://www.members.optusnet.com.au/nswmn1/Lights_in_DCC.htm
Rich
I appreciate all the info Rich. I just put that site in my favorites for future reference.
While the MRC power packs may not always have a separate slide switch to control the pulse power, most all of them do use pulse of some form. I have heard the MRC 1300 is one of the units that has automatic pulse injection, though I haven't ever used one. I do have an MRC 2800 Tech II Dual Power controller that I have used for my T-Trak modules, and to date, it has scrambled the decoders of at least four of my locos, three with TCS and one Broadway Paragon with sound in an E-8. The Paragon unit was restored only after several resets (both soft & hard) were performed. The TCS units' resets have not been attempted yet because I need to set up my laptop computer programmer to do it. Different DC power packs seem to have different pulse effects on decoders, and some decoders seem to be more sensitive than others to the effects of that pulse. If you only have DC power packs, and your loco has a jumper plug, then it's probably a good idea to remove the decoder and use the jumpers. Most N scale locos don't have room for a jumper socket, so that's not usually an option.
Bill in FtL
You could be right Bill, I am no rocket scientist or electrical engineer, but I would like to see something about this in writing instead of just a "I heard" about pulse. It seems counter-intuitive to me that they would produce a pack with a "Pulse" switch on it and one w/o and the one w/o would have the same feature.
Regardless, it does not appear the 1300 was the problem here.
The older MRC Tech II power packs used a built in pulse width modulation scheme that worked great for older DC locos, but is known to cause problems with newer decoder equiped locos.
I used an MRC 1300 in my repair shop to verify decoder equiped locos would operate on DC before making any DCC changes. While it does have a 'chopped sine wave' output, it does not use PWM. And it never caused any decoder problems in the 14 years I used it.
Len
Thank you for clarifying and confirming what I had thought and had said Len.
When you say "older packs", how old are we talkin?
Sorry, I should have been clearer. By "older Tech II's", I just meant older than the MRC 1300/1370 power packs. Not that there was a difference between early and late Tech II's. All of the Tech II's I know of had the built in PWM for "smooth starts".
Len
That is interesting bc I have seen some in the Tech II line have the pulse switch and some w/o. Like I alluded to earlier, I would find it strange that one Tech II model with a pulse switch would be identical to a Tech II model w/o one.
The "Pulse" switch added in spikes of higher voltage at lower throttle settings on top of the PWM to get the old open frame motors started. This was a holdover from ealier straight DC throttles.As the throttle advanced, the spikes would get smaller until at some predetermined point they would go away.
With PWM the voltage comes in pulses (not higher voltage spikes) spaced farther apart at low speeds, they get wider and closer together as speed increases, until they merge into essentially a flat DC line.
It's easier to visualize if you think of narrow square waves, with wides spaces between them at low speeds. As the speed setting increases, the square waves get wider, and the spaces between them get smaller. A meter attached to the output shows an apparent voltage increase, as the time voltage is present gets longer.
The Tech II's don't actually use square waves, it's more like partially rectified AC to create the PWM. At some point, someone at MRC figured out you don't actually need the "Pulse" voltage spikes on top of PWM, and the "Pulse" switch went away.
Len
Ok Len, thank you for taking the time to explain the physics of it. So, are you saying that a Tech II 2400 with a Pulse switch, will operate the same as a Tech II 1400 w/o the Pulse switch? Both are Tech IIs.
Since you mentioned the Railpower 1370 earlier, I have to point out that there is a fellow (Glen on MRR) on the net who claims his oscilloscope found a manufacturers defect (really a lack of including a resistor) in them, affecting their operation. A GOOGLE search should turn it up.
The Tech II's operate the same, using PWM, with the pulse switch off. Turn the pulse switch on and you get the spikes on top of the PWM on the ones with the switch. Since the PWM used has very steep sides to the pulses, not good for motors that don't have a lot of mass, as it generates heat.
Current DCC systems, and later MRC power packs, also use PWM, but the slopes of the pulses is more like / \ instead of | |, generating much less heat. But still more than you want to put into a coreless motor without a decoder using address '0'.
I tracked down a thread on Trainboard from 2009 where a fellow named Glenn said:
QuoteWhile the MRC 1300 is OK, avoid the MRC1370 at all costs. A manufacturing defect on the MRC1370 results in full wave power at all speed settings, unlike the MRC 1300 with correct half wave output at low throttle settings.
That's not a manufacturing defect. All it means is the MRC 1300 use half-wave rectified AC on it's track output, like the older Tech II power packs, while the MRC 1370 uses full-wave rectified AC, resulting in a smoother DC output on it's track output. There's a fairly decent explanation of the difference here: http://www.radio-electronics.com/info/circuits/diode-rectifier/full-wave-rectifiers-circuits.php (http://www.radio-electronics.com/info/circuits/diode-rectifier/full-wave-rectifiers-circuits.php)
All it really means is the MRC 1370 is actually providing more power at a given throttle setting than the MRC 1300, while the pulsing effect of the half-wave output of the MRC 1300, like the Tech II's, may give better starting performance to older locos.
Why someone who doesn't understand something as basic as half-wave vs full-wave rectification is looking at things with an O-scope beats me.
Len
Thank you Len, I appreciate your sharing all this knowledge you have on this subject.
So getting back to my question, does this mean then that simply bc a model is a Tech II, does not mean it has the same Pulse feature, unless it has a Pulse switch?: The Tech II's operate the same, using PWM, with the pulse switch off. Turn the pulse switch on and you get the spikes on top of the PWM on the ones with the switch.
Why someone who doesn't understand something as basic as half-wave vs full-wave rectification is looking at things with an O-scope beats me.
To answer your question: a) bc he is nuts; b) bc he has nothing better to do with his time ??
I would not know about the time, I'm one of those "10 minute" modelers.... ;)
Quote from: jbrock27 on March 01, 2015, 12:26:08 PM
Thank you Len, I appreciate your sharing all this knowledge you have on this subject.
So getting back to my question, does this mean then that simply bc a model is a Tech II, does not mean it has the same Pulse feature, unless it has a Pulse switch?: The Tech II's operate the same, using PWM, with the pulse switch off. Turn the pulse switch on and you get the spikes on top of the PWM on the ones with the switch.
Yes. Pulse switch = PWM with spikes when on, No pulse switch = PWM only.
The main difference between the Tech II's and the later, e.g., 1300, power packs is the PWM on the Tech II's had the straighter sides (| |), while the later ones are more sloped (/ \).
Len
I know, I have one of each, which was why it was important to me to get clarity on this. At first, it appeared you were saying that all Tech II models were alike, Pulse switch or no. Thanks again.
I tracked down a thread on Trainboard from 2009 where a fellow named Glenn said:
QuoteWhile the MRC 1300 is OK, avoid the MRC1370 at all costs. A manufacturing defect on the MRC1370 results in full wave power at all speed settings, unlike the MRC 1300 with correct half wave output at low throttle settings.
That's not a manufacturing defect. All it means is the MRC 1300 use half-wave rectified AC on it's track output, like the older Tech II power packs, while the MRC 1370 uses full-wave rectified AC, resulting in a smoother DC output on it's track output. There's a fairly decent explanation of the difference here: http://www.radio-electronics.com/info/circuits/diode-rectifier/full-wave-rectifiers-circuits.php (http://www.radio-electronics.com/info/circuits/diode-rectifier/full-wave-rectifiers-circuits.php)
All it really means is the MRC 1370 is actually providing more power at a given throttle setting than the MRC 1300, while the pulsing effect of the half-wave output of the MRC 1300, like the Tech II's, may give better starting performance to older locos.
Why someone who doesn't understand something as basic as half-wave vs full-wave rectification is looking at things with an O-scope beats me.
Len
[/quote]
Len,
You are correct that half-wave gives better starting performance. Also better slow speed performance. Because there are only 60 half-wave sinusoidal pulses per second (with intervening gaps) as opposed to 120 PPS full-wave (assuming a 60HZ AC power source) each pulse must be a higher voltage and current for the same motor speed. This causes the motor to output a higher torque at that speed than it would have at 120 PPS.
The MRC1370 did have a manufacturing defect. This was back in 2002 for the circuit board identified by the numbers PC-1370M-1 and 16-01-01. MRC might have fixed the problem since then; I don't know. What I do know is that a MRC representative told me in a telephone conversion that the 1370 should should be half-wave output at low throttle settings like other similar MRC products, and seemed surprised when I reported that it did not.
If you have one of these units you can determine (and fix) any defects by opening the case, unplug it from the AC outlet first. The 'security' screws are easily overcome by filing a notch in the blade of a regular flat screwdriver to make it fit the screw.
Look at the circuit board to see if there is an empty component location labelled 'R1'. The defective boards have an error in the copper etch that connect one end of R1 to the output of the bridge rectifier. This resistor should have been connected to one of the AC terminals of the bridge rectifier instead. Since the manufacturer chose to leave out this resistor it is obvious that the manufacturer was aware of the problem and decided to ship the product anyway.
If your R1 is missing, fix the problem by installing a 5% 5.6 kilohm resistor, 1/4 watt is fine, one lead into the pcb hole that connects to the wiper (center terminal) of the speed control. Leave the other lead of the new resistor out of the pcb, instead use a wire to connect it to one of the AC input terminals of the bridge rectifier. Which AC input terminal does not really matter unless you want ALL your power packs to be phased the same way, so that when the locomotive crosses between blocks that are each driven by separate power packs it does not temporarily speed up by receiving out-of-phase pulses (temporary full-wave while stradding blocks) from the two separate power packs. If you do not have an oscilloscope you will have to determine the phasing by experimentation.
Now your MRC1370 should output half-wave at slow throttle setting, increasing gradually to full-wave as the throttle is advanced to full speed like it was designed to do. By gradually I mean that the suppressed sinuoidal pulses in the 'gap' between the main pulses will increase in amplitude relative to the main pulses. Your locomotives will now run even smoother at slow speed.
And by the way, I am the 'Glenn' you refer to in the above quote; and my occupation for the last 40 years has been electronic design engineering. I do know the difference between half-wave and full-wave rectification
Regards,
Glen
Glen, do you happen to have any pics of your fix? You know what they say ;)
jbrock27
The original pics were lost in a hard drive crash long ago, but was able to recover the .doc file from a forum. Being new to this Bachmann forum cannot figure out how to attach it. However, the file with the pics can be seen at either
https://groups.yahoo.com/neo/groups/Z_Scale_Electronics/info
https://groups.yahoo.com/neo/groups/MTL-ZScaleLocomotiveMaintenance/info
Use Photobucket to then get the pics here.
PS-Sorry if this is a silly question, but how come I only am seeing 2 pics? One is sine wave kinda stuff and the other looks like the bottom of RR truck.
Quote from: jbrock27 on December 03, 2015, 12:37:57 PM
but how come I only am seeing 2 pics?
Sorry, was in a hurry this morning to get to work. Those are the groups home pages. Click on 'Files' near the top and then to the MRC1370 file.
"Files" (at least the one I see which is to the left of "About") is grayed out and nothing happens when clicking on it.
Quote from: jbrock27 on December 03, 2015, 08:28:44 PM
"Files" (at least the one I see which is to the left of "About") is grayed out and nothing happens when clicking on it.
Try the other website Locomotive Maintenance, that one does not need moderator approval for membership.
It is the same thing there bro.
Quote from: jbrock27 on December 03, 2015, 09:14:52 PM
It is the same thing there bro.
Not sure why, they work for me but then I am the moderator.
Do you have a yahoo account? Maybe yahoo denies access to groups unless you register on yahoo first.
Do you know if there is any way to attach this file here? When I try I get a message something like "Upload buffer full" and the file is only 110KB so should work. The pics are embedded in the Word file and I don't think I can extract them, and as I said the originals are lost.
MRC1370 Manufacturing Defect and Solution
(http://i1027.photobucket.com/albums/y332/zeeglen/WaveformsYelMRC1400BluMRC1370Defect_zpsnbkbot1o.jpg)
Above: The yellow trace is a MRC1400 working properly at low speed and outputting mostly half-wave rectified with low voltage pulses in the gaps between the main higher voltage pulses. As the throttle is advanced both the low and higher voltage pulses increase, but the low voltage pulses increase faster until at full speed all pulses are the same voltage, ie full-wave rectified. The half-wave causes the motor to generate higher torque at low speed.
The blue trace is the MRC1370 with the manufacturing defect. It outputs full-wave at all voltage (speed) levels. With the fix shown below it will instead perform like the MRC1400 (and others) as intended.
(http://i1027.photobucket.com/albums/y332/zeeglen/MRC1370DefectSchematic_zpsmilcbyhr.jpg) Above is the MRC1370 schematic showing where the missing R1 is connected in error. Install a 5% 5600 ohm 1/4 watt resistor at the missing R1 location. Either cut the trace where shown or lift that lead of the new R1 out of the pcb and connect instead to the diodes AC input (transformer secondary). Which wire of the transformer secondary is usually not important unless you run more than one power pack on the same train and need to have all phased the same way. Use oscilloscope or experiment with phase to ensure locos do not speed up when straddling blocks powered from two separate power packs. When properly phased all power packs will source the main pulse at the same time, ie on the same half cycle of the AC powerline.
Thank you. The schematic is better, but I was hoping for some pics of the guts of the power pack. Had you taken any of the work on it or no Glen?
Quote from: jbrock27 on December 04, 2015, 07:14:21 AM
but I was hoping for some pics of the guts of the power pack. Had you taken any of the work on it or no Glen?
No, it was pretty straightforward, but I still have the cheater screwdriver and the power pack is around here somewhere. Will get some photos this weekend, and now that I learned how to use photobucket will post them.
Thanks much for your efforts and help! :)
Quote from: jbrock27 on December 04, 2015, 08:23:37 PM
Thanks much for your efforts and help! :)
Here are the photos you asked for, these are better for those who wish to fix their own MRC1370 power packs. Don't know if MRC would be willing to correct this manufacturing flaw on existing units, but one could ask them. I approached MRC about this 10 years ago, they ignored the problem. I guess, like Volkswagon and their Diesel emissions, they figured no one would notice.
(http://i1027.photobucket.com/albums/y332/zeeglen/MRC1370CheaterScrewdriver_zpsp7zontg8.jpg)
Above is the tool to undo the 'security' screws. All it takes is a needle file to cut the slot into a regular screwdriver.
BE SURE TO UNPLUG THE POWER PACK FROM THE AC OUTLET BEFORE DIS-ASSEMBLING THE CASE!(http://i1027.photobucket.com/albums/y332/zeeglen/MRC1370DefectR1Missing_zps18adfqsm.jpg)
Above: Although not necessary, if you take a defective unit apart enough to lift out the printed circuit board (PCB) you will see an empty component location labelled R1. This is a little to the left of center. You have to pry up the heatsink (the flat metal plate) to make the external knob slip off the shaft of the speed control, then unscrew the large power transistor from the heatsink. Do NOT remove the white thermal grease; this is needed to transfer heat from the transistor to the heatsink.
(http://i1027.photobucket.com/albums/y332/zeeglen/IMGP1467DefectNewR1Installed_zpsx7plzxgg.jpg)
It is not necessary to remove the PCB to install the fix on the solder side of the PCB which is accessible as soon as the 4 screws holding the box together are removed. The absence of R1 can be seen by the lack of wires protruding from the solder joints at the empty R1 location. Solder in a new resistor as shown. Anything between 5000 and 10000 ohms will work. Be sure to use insulating sleeving on the resistor wires so they do not short circuit to anything else on the PCB. The resistor wire soldered at top center of the photo can connect to either of the pads (but not both at the same time!) to which the red transformer wires are connected. The choice of which pad is determined by the desired phasing as discussed in earlier posts. Only matters if you run a train over blocks powered by more than one power pack.
You can see the fix is quite simple. So why could MRC not have done this during manufacture?
Awesome Glen! Thank you.
I made up one of those screw drivers a few years ago to open up a Railpower 1300. Had to fix a stripped AC terminal screw. Even though I was able to fix that, in the process, I messed up the DC control. Ordered a pack of transistors from China and a pot from Mouser, but could not repair it. At that point, it was not worth further investment of capital and relegated it to use of the AC terminals for switch motors.
Quote from: jbrock27 on December 06, 2015, 09:24:49 AM
Awesome Glen! Thank you.
You are welcome
jbrock27. Glad to help when I can.
I am curious as to whether MRC ever corrected this defect. I see they are still selling the MRC1370. It would be interesting for owners of these units who are reading this to open them up and see, and add the fix while opened if desired. I emailed MRC asking, but based on their prior lack of response to my queries I doubt if I will hear from them.
Also those who do install the fix to report on the starting and slow speed running improvements. I know this made a huge difference for the MTL Z Scale F7.
Don't have a answer why they have not address it. Acting like VW as you pointed out. Maybe bc not enough "noise" generated about it and certainly no one is going to go the press with a hobby power pack issue, no that many souls would pay it any attention anyway. It would not make 60 Minutes.