[Q] What is Dynamic Brakes?
- Thread starter gtasa
- Start date
So far as I understand, dynamic breaking is the process of using a locomotive's traction motors as large resistors, and venting of the generated energy as heat (thus the large topside heatsinking). This slows the locomotive without the use and wear of break pads.
Cheers,
John
Cheers,
John
Confirming what ZapperJet says.
More detail here: http://www.trains.com/trn/default.aspx?c=a&id=197
Have fun,
More detail here: http://www.trains.com/trn/default.aspx?c=a&id=197
Have fun,
NSWGR_46Class
Just call my Captain Rude
Using the traction motor as Generators would be better, resistors can not produce energy.
Hot_Box_Detector
Member
clarification....
Dynamic braking is using the traction motors on the loco in the reverse way that they are "normally" used.
Normally, the diesel engine drives a generator, or, alternator that produces power that is fed TO the traction motors, which, of course moves the train forward. When the throttle is moved back to a lower setting the train is still moving, thus the traction motors are still turning, and will GENERATE power. If this power is fed FROM the traction motors to a LOAD, i.e. resistor bank... it will actually assist in slowing down the train. Regular air brakes use FRICTION to stop a train. Slowing down a train using the traction motors uses the electricity generated by the traction motors, so the word DYNAMIC is applied.
" from Greek dynamikos powerful, from dynamis power" as in dynamo or generator.
Just a little side note... my Honda Insight uses dynamic braking to charge it's batteries. If I am going over 15 MPH and just barley tap the brake pedal, the battery charge indicator goes to FULL CHARGE. Same as a locomotive, my car is using it's "traction motor" as a generator. Instead of dumping the power into a resistor bank, it dumps the excess power into the onboard batteries. Same principle, different application, same result; the moving vehicle slows down...
Dynamic braking is using the traction motors on the loco in the reverse way that they are "normally" used.
Normally, the diesel engine drives a generator, or, alternator that produces power that is fed TO the traction motors, which, of course moves the train forward. When the throttle is moved back to a lower setting the train is still moving, thus the traction motors are still turning, and will GENERATE power. If this power is fed FROM the traction motors to a LOAD, i.e. resistor bank... it will actually assist in slowing down the train. Regular air brakes use FRICTION to stop a train. Slowing down a train using the traction motors uses the electricity generated by the traction motors, so the word DYNAMIC is applied.
" from Greek dynamikos powerful, from dynamis power" as in dynamo or generator.
Just a little side note... my Honda Insight uses dynamic braking to charge it's batteries. If I am going over 15 MPH and just barley tap the brake pedal, the battery charge indicator goes to FULL CHARGE. Same as a locomotive, my car is using it's "traction motor" as a generator. Instead of dumping the power into a resistor bank, it dumps the excess power into the onboard batteries. Same principle, different application, same result; the moving vehicle slows down...
SantaFebuff
That's So Trainz Forum
Interesting information. That's a great source for everything you may need to know!
Cheers,
Joshua
Cheers,
Joshua
A little boost...
Only traction motors that have two sets of windings can be used for dynamic braking...the case has to be setup with a motor winding, and a generating winding.
A 10-second pause between power at idle & set-up for db is needed to allow residual current produced in power mode to dissipate.
Remember the science class experiment where you wound a wire around a nail? Add current(a battery), you have a magnet...
The armature in a traction motor being wound with wire, naturally produces a magnetic field current. When in db mode, the generator windings(in the traction motor) produce a opposing current...this does a lot of the braking effect. The residual energy generated goes to the (GIANT) resistors, also the cooling fan that cools those resisters. The more energy generated, the faster the fans turn until the overwhelming heat often burns the paint off the carbody(SP SD45's often show this).
Long grades out in the west could actually cause the resisters to glow at night...
For db to work in Trainz, the enginespec must contain settings in the config files to work...zero's in the db section don't.
Dynamic braking is the first option, as it is quicker to release than the automatic brake & all Class I's in the US-America mandate it's use as first option.
By the way, most of NorfolkSouthern37's later production includes accurate simulation of the db fans, certainly all the JointedRail locomotives that have top-mid-mounted db fans....they only turn in db mode-Excellent!
Only traction motors that have two sets of windings can be used for dynamic braking...the case has to be setup with a motor winding, and a generating winding.A 10-second pause between power at idle & set-up for db is needed to allow residual current produced in power mode to dissipate.
Remember the science class experiment where you wound a wire around a nail? Add current(a battery), you have a magnet...
The armature in a traction motor being wound with wire, naturally produces a magnetic field current. When in db mode, the generator windings(in the traction motor) produce a opposing current...this does a lot of the braking effect. The residual energy generated goes to the (GIANT) resistors, also the cooling fan that cools those resisters. The more energy generated, the faster the fans turn until the overwhelming heat often burns the paint off the carbody(SP SD45's often show this).
Long grades out in the west could actually cause the resisters to glow at night...
For db to work in Trainz, the enginespec must contain settings in the config files to work...zero's in the db section don't.
Dynamic braking is the first option, as it is quicker to release than the automatic brake & all Class I's in the US-America mandate it's use as first option.
By the way, most of NorfolkSouthern37's later production includes accurate simulation of the db fans, certainly all the JointedRail locomotives that have top-mid-mounted db fans....they only turn in db mode-Excellent!
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norfolksouthern37
what's a normal map?
but of course. and thank you for noticing.
NSWGR_46Class
Just call my Captain Rude
Just a little side note... my Honda Insight uses dynamic braking to charge it's batteries. If I am going over 15 MPH and just barley tap the brake pedal, the battery charge indicator goes to FULL CHARGE. Same as a locomotive, my car is using it's "traction motor" as a generator. Instead of dumping the power into a resistor bank, it dumps the excess power into the onboard batteries. Same principle, different application, same result; the moving vehicle slows down...
NO Sorry that is wrong, if you store the power for later use thats called regenerative braking thats a whole other type of fish, it is the type of braking as used on Electric Locomotives
http://en.wikipedia.org/wiki/Regenerative_brake
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cascaderailroad
New member
If you drive a 1 mile long train, on an 11 mile long, 2% downhill gradient in Cab Mode, and at @ 10 mph you put the throttle in Run "0" momentarily, then quickly put the Dynamic brake in the "Full" position, then quickly increase the throttle to "Run 8" ... @ 6 locos (4 lead & 2 more trailing) will slow the train to a respectable speed. You may have to make several initial service brake applications and releases, over and over again, in conjunction with the dynamic brake, if the train gets out of control above 45 mph.
Be careful not to Psssssss away your air resivoir, or you will have a runaway like what happened on the Horseshoe Curve in 1994. The train crew radioed in to Alto tower, that on the "Slide", they had no control of the train brakes, and had lost their air, as the train speed quickly was exceeding 50 mph. Several harrowing miles later, after rounding the "Curve" at well above 65 mph the TTX train derailed just east of the "Curve". All tracks were blocked, but one of the tracks was temporarily put back in service through the derailment site within several hours time.
Another TTX Mail train derailed downhill on the "Slide" in the 70's, and an army of workers had to retrieve each and every letter scattered down the sticker bush infested, timber rattler, and copperhead infested, 200' deep mountainside in the area of AG Alligrippis Curve.
Another notable accident on the Middle Division was on the Old Allignment original bore at Spruce Creek Tunnels, where an eastbound coal train was trapped in the tunnel when soft unstable earth made the tunnel bore "cave in". After several attempts to shore up the inside of the tunnel with steel girders, which were constantly failing ... the old allignment tunnel bore was finally taken permanently out of service, and today and the rails are removed.
Some Trainz locos have better sound effects than others. And even the Default Auran locos config files can be altered so that the paper cut out freight trucks and poorly designed loco trucks, horn, bell and enginesounds are replaced by a better looking animated wheels, with better sounding engine sounds and dynamic braking sound effects, kuids.
Some of the best sounding locos IMO, are the UP U50, the UP Gas Turbine, all of Joram24's locos, all of Jointed Rail, Erecting Hall, and MG Trainz F7's. There are dozens and dozens of other totally superior sounding Trainz locos ... too many to list.
The Dynamic Brake howling sound is awsome, if you "free roam" following your train, downgrade.
Be careful not to Psssssss away your air resivoir, or you will have a runaway like what happened on the Horseshoe Curve in 1994. The train crew radioed in to Alto tower, that on the "Slide", they had no control of the train brakes, and had lost their air, as the train speed quickly was exceeding 50 mph. Several harrowing miles later, after rounding the "Curve" at well above 65 mph the TTX train derailed just east of the "Curve". All tracks were blocked, but one of the tracks was temporarily put back in service through the derailment site within several hours time.
Another TTX Mail train derailed downhill on the "Slide" in the 70's, and an army of workers had to retrieve each and every letter scattered down the sticker bush infested, timber rattler, and copperhead infested, 200' deep mountainside in the area of AG Alligrippis Curve.
Another notable accident on the Middle Division was on the Old Allignment original bore at Spruce Creek Tunnels, where an eastbound coal train was trapped in the tunnel when soft unstable earth made the tunnel bore "cave in". After several attempts to shore up the inside of the tunnel with steel girders, which were constantly failing ... the old allignment tunnel bore was finally taken permanently out of service, and today and the rails are removed.
Some Trainz locos have better sound effects than others. And even the Default Auran locos config files can be altered so that the paper cut out freight trucks and poorly designed loco trucks, horn, bell and enginesounds are replaced by a better looking animated wheels, with better sounding engine sounds and dynamic braking sound effects, kuids.
Some of the best sounding locos IMO, are the UP U50, the UP Gas Turbine, all of Joram24's locos, all of Jointed Rail, Erecting Hall, and MG Trainz F7's. There are dozens and dozens of other totally superior sounding Trainz locos ... too many to list.
The Dynamic Brake howling sound is awsome, if you "free roam" following your train, downgrade.
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NSWGR_46Class
Just call my Captain Rude
Oh not true althrough not often used as traction motors any permag motor can be used as a DC Generator with only one set of windings.
norfolksouthern37
what's a normal map?
what dynamic brake howling sound??? i would have included one but since the dynamic braking operation in trainz is NO WHERE near prototypical i opted out. the way trainz makes you switch a switch and then jam the throttle open along with engine sounds revving up just made me not want to bother. i still have a place to put them if they ever unlink that engine sound and tone it down some.
cascaderailroad
New member
This is dynamic brake howling sound http://s525.photobucket.com/albums/.../?action=view¤t=KickingHorsePassWIP.flv ... all it takes is a long downhill gradient, and a speed of 10 mph ... throw the throttle off ... throw the dynamics on full, or half ... and throw the throttle back on forward / full power ... sit back and follow the locos in free roam. Use the keyboard to make initial braking now and again (A Apply, Q Release, V Sand), to keep the train under control.
Running Trainz in Cab mode (using -freeintcam line in the trainsoptions file) totally rules !
Thats exactly the way the prototype operates the cab controls.
Running Trainz in Cab mode (using -freeintcam line in the trainsoptions file) totally rules !
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All of the F's on my site are just reskins of NorfolkSouthern37's Engines. All the credit goes to him. I just supplied some repainting skills.
norfolksouthern37
what's a normal map?
no not entirely. i mean yea you can almost argue this for old control stands with a mode selector switch since you use the same lever for the braking as you do for the throttle once you have changed the mode, but its not running the throttle up on the engine like Trainz does in any case. what trainz does is use the engine sound again with the throttle when you switch to dynamic braking mode.
the trainz default cabs use the dynamic brake lever like a toggle switch, on or off. this is not how they work. in a real cab like that you put the throttle to idle, wait the appropriate amount of time, then slide the dynamic lever to the desired strength (they do not notch like a throttle). this will activate the grid and cooling and you would hear the braking fans etc, but the engine would not throttle up except to maybe cool itself, and even that depends on what locomotive it is.
in that video its exactly as i said, the sound you hear is simply the engine in notch 8, that howl is the 710 prime mover blower. i would know if there were any dynamic braking sounds and there are none in trainz. as i said ive left a section in my script for this when they decide to turn off the engine sounds during dynamic braking in TRS.
Trainz-brain-storming...
Thanks Justin, I know you have studied this feature for Trainz.
Your right, depending on the locomotive & railroad it belongs to, some locomotives can be run in notch-4, to supply compressed air for train-line-charging...Southern Railway System SD's had this option, controlled by a key switch on the controller.
So, I pre or advance to braking before the downgrade, or just let the train drift to the downgrade, then set-up for db, then place the throttle in the 4th-notch...by then, fans are howling anyway, so that provides db as well as a "mock" sound to suit me...
An engineer told me once that (with non-extended range db) if you gain over a half-mile per hour with full braking applied, you need to use the Automatic Brake, bailing off the Independent brake to prevent locomotive wheel lock-up(Independent brake bailing is not at this time simulated or required in Trainz).
The only time I use 'full' db in Trainz, is on a long down-grade...I have lost reservoir pressure before, thankfully without loosing the train altogether, which is a good feeling & proof of the effect of a great train-simulation...to be that involved with the gaming of Trainz.
Thanks Justin, I know you have studied this feature for Trainz.Your right, depending on the locomotive & railroad it belongs to, some locomotives can be run in notch-4, to supply compressed air for train-line-charging...Southern Railway System SD's had this option, controlled by a key switch on the controller.
So, I pre or advance to braking before the downgrade, or just let the train drift to the downgrade, then set-up for db, then place the throttle in the 4th-notch...by then, fans are howling anyway, so that provides db as well as a "mock" sound to suit me...
An engineer told me once that (with non-extended range db) if you gain over a half-mile per hour with full braking applied, you need to use the Automatic Brake, bailing off the Independent brake to prevent locomotive wheel lock-up(Independent brake bailing is not at this time simulated or required in Trainz).
The only time I use 'full' db in Trainz, is on a long down-grade...I have lost reservoir pressure before, thankfully without loosing the train altogether, which is a good feeling & proof of the effect of a great train-simulation...to be that involved with the gaming of Trainz.
norfolksouthern37
what's a normal map?
hehe, yea i havnt done it in trainz, but playing MSTS i lost pressure once, and actually felt nervous and scared. i was able to regain control with the dynamic brake and got onto some level track at a passing siding, letting the air charge up. if i hadn't hit that level spot on the grade i would have lost it for sure, but just thinking that i got nervous over a game made me chuckle a little.