(DCS) Electrical Noise Interference's.

RE: (DCS) Electrical Noise Interference's.

Project: (bus and feeder wires)

Of course a fast majority of you have a completed operating model train layout.
This would really only apply to individuals building a new model train layout.
Mark Gurries:
What are the benefits of Twisted Pair Wiring?
https://sites.google.com/site/.../twisted-pair-wiring
Twisted pair wiring offers the unique combination of :
1) Reduced noise pickup (low level signals) Think shielded cable.
2) Reduced noise transmission (high power) Think shielded cable.
3) Higher speed communications (Higher usable signal frequency range or bandwidth)
--> Where to use Twisted Pair Wiring in DCC?
--> Where NOT to use Twisted Pair Wiring in DCC?

ED-RRR ......

View Picture Below --> Twisted Wires

RE: (DCS) Electrical Noise Interferences.

Project: (ground wires)

Mark Gurries:
Booster Connections & Power
https://sites.google.com/site/...er-connections-power
NO EARTH GROUND WIRING
Simply put: Don't connect any part of your DCC system directly to Earth Ground.
Any term "Ground" used in regard to the DCC system DOES NOT MEAN YOU connect it to Earth Ground.
This is the hazard of using the word "ground" instead of the better and more accurate word "common" as in Booster Common.

ED-RRR ......

RE: (DCS) Electrical Noise Interference's.

Project: (electric motor switch machines)

CTI - Model Railroad Computer Control
http://www.cti-electronics.com/appnotes.htm
Noise Reduction Techniques
Motors are natural arc generators.
Arcing is caused by the inherent make/break connection between the motor’s brushes and commutator plates.
Arcing produces high voltage, high frequency electrical spikes that can travel easily (either by direct electrical connection,
or via electromagnetic emission through the air) onto other nearby electrical circuits.
The solution is simply to install a small capacitor (between 0.01 and 0.1 uF is a good rule of thumb) across the motor leads.
The capacitor should be placed as close to the motor as possible, preferably right at the motor itself.
This capacitor will serve to filter out the high frequency electrical arc before it can propagate out of the engine, and onto adjacent wiring.

Tortoise Switch Machine:
A CTI electrical engineer informed me that the closer the commutator noise suppression capacitor is located to the motor terminals,
the better it will work.
Adding a 0.1Uf 50V capacitor at the (x2) motor terminals on the switch machine will help.

ED-RRR ......

View Picture Below --> Capacitor

RE: (DCS) Electrical Noise Interference's.

Project: (solenoid switch machines)

CTI - Model Railroad Computer Control
http://www.cti-electronics.com/appnotes.htm
Noise Reduction Techniques
The solenoids found in snap-action switch machines are another notorious source of noise in model railroads.
When the solenoid is deactivated following a switch throw, the magnetic field built up in the solenoid begins to collapse.
As the coil tries to maintain the magnetic field, a large transient voltage spike ensues. These can easily reach 100 Volts or more.
This spike can readily couple into adjacent wiring, or can cause momentary ground bounce.
Fortunately again, this scenario is easy to avoid.
We simply need to install a “snubber” diode across the coil of each solenoid.
Most snap-action switch machines actually have two solenoids,
so a separate diode is required for each.
This diode “clamps” the voltage spike to the diode drop voltage (a mere 0.7V),
so it’s much less likely to affect neighboring circuits.
A 1N4002 diode will normally work fine for most model railroad applications.
1N4002 = 100V/1A/1.1V  (general purpose rectifier).
The direction in which to install the diode depends on whether your switch’s solenoids are wired as common-anode or common-cathode.
Both cases are illustrated.

ED-RRR ......

View Picture Below --> Diodes

RE: (DCS) Electrical Noise Interference's.

Project: (motor and solenoid switch machines)

CTI - Model Railroad Computer Control
http://www.cti-electronics.com/appnotes.htm
Noise Reduction Techniques
Another simple but effective technique is to twist the two leads of the wires driving noisy high-current loads such as motors and solenoids.
Since the currents in each wire are traveling in opposite directions,
twisting the two leads closely together causes their respective magnetic fields to overlap and cancel one another, minimizing emissions into the surrounding environment.
About six twists per foot are generally adequate.

ED-RRR ......

View Picture Below --> Twisted Wires

RE: (DCS) Electrical Noise Interference's.

Project: (V-AC power supply)

(D-CC) "Digital Command Control" systems, do "Not Warn You"
about using V-DC switching power supplies. (Electrical Noise).
(D-CS) "Digital Command System" systems, "Do Warn You" you
about using V-DC switching power supplies. (Electrical Noise).

Fact:
It is recommended by MTH (D-CS) to use a V-AC power supply, to omit "Electrical Noise",
for  (D-CS) "Digital Command Systems".
- MTH #40-1000A = 18.V-AC / 100 Watt / 5.6 Amps (About US $100.00)
- Lionel PowerHouse = 18.V-AC / 180 Watt / 10. Amps (About US $100.00)
are small unregulated V-AC power supplies.

-

Fact:
NCE (D-CC)
Brutus = 18.V-AC / 180 Watt / 10. Amps (About US $190.00)
is a very large unregulated V-AC power supply.
- Has a very large V-AC transformer
- Has a 6" cooling fan to remove excess heat for increased "Power Efficiency"

Question:
Comparing the "Small" (Lionel PowerHouse) 18.V-AC / 10.Amp power supply,
to the very large (NCE Brutus) 18.V-AC / 10.Amp power supply,
which power supply do think would supply
--> the "Best Constant" 18.V-AC / 10.Amps / 180 Watt "Power Supply" ?

ED-RRR ......

Ed, what is the point of all this?

You are replying to your own posts, and most of this information has been "out there" and well known for years.

Interesting post..in the marine electronics environment twisted wiring pairs ,shielded wire and proper filtering is paramount to proper installation

OGR Webmaster posted:

Ed, what is the point of all this?

You are replying to your own posts, and most of this information has been "out there" and well known for years.

Hello; Rich

We all know that almost everyone is using a "Unregulted" V-AC power supply to thier,
to (D-CS) "Track Interface Units" (TIU).

Sorry, not to be rude,
but did anyone ever consider, all the different variables, when using a V-DC power supply,
to the MTH (D-CS) "Track Interface Units" (TIU) ?

That there are (x2) different "Switching Power" supplies
- Using (PWM) pulse-width modulation into a frequency signal
- "Not" using (PWM) pulse-width modulation

That a V-DC switching power supply, using only using (PWM) pulse-width modulation,
into a "VDC-VDC Booster",
- Will output a constant regulated 18.V-DC power supply
- Will output a constant regulated 10.Amp power supply
- Will output no "electrical noise" interference
to the MTH (D-CS) "Track Interface Unit" (TIU).

ED-RRR ......

RE: (DCS) Electrical Noise Interference's.

Information: (V-DC switching power supplies)

A linear regulated V-DC power supply regulates the output voltage by dropping excess voltage in a series dissipative component.
They use a moderately complex regulator circuit to achieve very low load and line regulation.
Are much larger in size and give off a lot of heat.
Also more costly to manufacture.
Linear regulated power supplies also have very little ripple and very little output electrical noise.

A switched-mode power supply (SMPS) is an electronic circuit that converts power using switching devices
that are turned on and off at high frequencies.
Storage components such as inductors or capacitors to supply power when the switching device is in its non-conduction state.
Are much smaller in size and give off very little heat.
Also much cheaper to manufacture.

What has caused the biggest problem with the switched-mode power supplies (SMPS),
there so many different "Types".
Medical (SMPS) power supplies use "EMI Filtering" to reduce electrical noise interferences.
There are "Common Ground" or "Interfering Ground Loop" ground connections
inside the power supply.
There are (SMPS) power supplies that come with pulse width modulation (PWM).
Pulse width modulation is used in a variety of applications including sophisticated control circuitry.

PWM (Pulse Width Modulated) power supplies are a type of switching power supply.
Pulse Width Modulation is generally used to help regulate the voltage in a switching power supply.
This is necessary when the current demand on the power supply or the charging system's supply voltage is not constant.
In a standard switching power supply (non PWM), each of the primary windings of the transformer
are driven with a 50% duty cycle (actually a bit less than 50%) square wave regardless of the current draw on the secondary or the supply voltage.
In a pulse width modulated power supply the duty cycle may vary from approximately 1% up to 50% (although it's not generally that wide of a range).

An effective method to reduce electrical noise is to use a DC-to-DC converter.
A switched-mode power supply (SMPS) "Must" be a PWM (Pulse Width Modulated) power supply.
The input signal is converted by means of PWM (Pulse Width Modulation) into a frequency signal,
and demodulated again on the output side to form an analog value.
An amplifier then generates a standardized analog signal.

Warning:
If you intend to use a DC-to-DC converter, be sure to add a 10.Amp fuse to protect the (TIU) unit.

ED-RRR ......

Show us your layout.

Where do you come up with this??

"Fact:
It is recommended by MTH (D-CS) to use a V-AC power supply, to omit "Electrical Noise",
for  (D-CS) "Digital Command Systems"."

I've never gotten involved with all these issues, in the many years I've run DCS since it was first issued.  I just run trains, and many of them at the same time.  The only noise I experience is on the Forum.

What's the bottom line in layman terms....  We have 4 tiu in super. all channels set to fixed mode. , each  channel is powered by a handle of a post war ZW  with 10 amp fast blow fuses between the ZW handle and each TIU input channel.

Anything else we might do?    I don't understand what you're getting at. 

Gregg posted:

....   I don't understand what you're getting at. 

 

 

 

I'm not sure who does?

You guys might want to stop feeding the troll. Maybe he'll eventually go away. He has already had at least one whole thread covering this nonsense deleted.

Casey Jones2 posted:

Where do you come up with this??

"Fact:
It is recommended by MTH (D-CS) to use a V-AC power supply, to omit "Electrical Noise",
for  (D-CS) "Digital Command Systems"."

Hello; [C. Jones]

I do not make up stories.
All of the information I [ED-RRR] post is always backed up by the manufacture or by a professional.

Fact: (#1)
(D-CC) and (D-CS) systems both use V-AC "Digital Square Wave Voltage".
The above information that I posted applies for (D-CC) and (D-CS) systems.
Mark Gurries is a NMRA (D-CC) electrical engineering representative and has written many articles warning about electrical noise.

Fact: (#2)
MTH DCS Tips and Operating help:
http://www.rayman4449.com/DCS_Tips.htm
Power Supply: (DC power)
Not Recommended: Switching mode power supplies: (These can be used but I would avoid them)

Question:
Why does Ray state to avoid switching mode power supplies ?

Ed-RRR......

Where are you citing these facts from? Does DCS use digital square wave voltage? Where does it say that? I'm not going to take your word for it

Matt Makens posted:

Where are you citing these facts from? Does DCS use digital square wave voltage? Where does it say that? I'm not going to take your word for it

MTH Authorized Service Tech

President Chief Operations Officer, The Lenny Lines

Hello: [Matt Makens]

You state to be a MTH authorized service technician.
It looks like that MTH should also teach their technicians how "Electronic Digital Signals" are sent through a "V-AC Track", to the (D-CS) "Locomotive decoder".

Fact: (#1)
Both (D-CC) and (D-CS) digital systems use V-AC track voltage.

Fact: (#2)
Both (D-CC) and (D-CS) digital systems send "Digital Signals" through the V-AC track
to the "Digital Locomotive".

Fact: (#3)
Analog signals = flowing wave voltage
Digital signals = square wave voltage
https://www.cs.tau.ac.il/~nin/...vne98/dsp/index.html

I hope that this has answered your question.

Ed-RRR......

RE: MTH (D-CS) and Lionel (D-CS).

I am so surprised that many individuals using (D-CS),
do not know "How" their (D-CS) system actually functions.

Ed-RRR......

ED-RRR posted:

RE: MTH (D-CS) and Lionel (D-CS).

I am so surprised that many individuals using (D-CS),
do not know "How" their (D-CS) system actually functions.

Ed-RRR......

Yeah but I know how to make it tick.