Faking a Voltmeter in a Cab View Is it possible to show variation in line voltage?
#1
Posted 30 October 2022 - 11:35 PM
When a train draws a heavy starting current, the line voltage may drop considerably.
(Of course power drawn, or regenerated, by other trains in the same electrical section may also cause voltage to fluctuate.)
So to fake fluctuations in a voltmeter due to the train drawing current we could do something like this:
For a nominal 600/660v dc supply.
Set voltmeter in cab display as a Type ( AMMETER GAUGE ) with the scale such that say 1000 A traction current = 430v and 0 A traction current = 630v.
All well and good, the voltmeter will now fall when the train draws a large current.
There is a problem though, we have a circuit breaker (or pantograph) and when the power is OFF we need the voltmeter to read 0v and not 630v!
This could be done using an overlay activated by Type ( PANTOGRAPH TWO_STATE ).
Is there any other solution that will give the features needed:
( a ) When pantograph is down and/or main circuit breaker is off, VOLTS = 0.
( b ) When pantograph is up and/or main circuit breaker is on, AND traction current = 0, VOLTS = line voltage.
( b ) When pantograph is up and/or main circuit breaker is on, AND traction current > 0, VOLTS < line voltage.
#2
Posted 30 October 2022 - 11:48 PM
Why should it be faked? Wouldn't it be better to create it?
I think it would give a more real experience than a fake.
Laci 1959
#3
Posted 31 October 2022 - 12:21 AM
Laci1959, on 30 October 2022 - 11:48 PM, said:
Why should it be faked? Wouldn't it be better to create it?
I think it would give a more real experience than a fake.
Laci 1959
I agree. That is best solution. I am just looking for something that will work until a developer can make the real thing.
#4
Posted 31 October 2022 - 11:15 AM
Weter, on 31 October 2022 - 07:20 AM, said:
Some cabs have warning lamp, which lits when undervoltage or electricity complete disappearance occurs, by the way.
Yes. True. I was thinking about a very old train that has only three gauges in the cab. Two huge moving coil meters (one for amps one for volts) plus a duplex gauge for the brake pipe and main reservoir. (Not even a speedometer much less any warning lights!)
#5
Posted 31 October 2022 - 11:30 AM
https://wiki.metrostroi.net/images/thumb/d/d7/Ема-502_НВЛ.jpg/480px-Ема-502_НВЛ.jpg
#6
Posted 31 October 2022 - 10:59 PM
Probably the easiest would be to ensure the function of random voltage changes in the trolley. E.g. -10% +5% of the voltage value for modern tracks with recuperation and -10% for other tracks.
This could be enough to create the illusion of voltage fluctuations in the traction trolley.
In real operation (e.g. in Central Europe), the situation is much more complicated. For example, on tracks where heavy coal trains run. There is a situation where the train has to wait for an appropriate moment to start.
#7
Posted 01 November 2022 - 12:48 AM
Lamplighter, on 31 October 2022 - 10:59 PM, said:
The drivers' instructions for an old d.c. electric locomotive here look complicated too!
https://i.imgur.com/XfvTWXK.jpg
https://i.imgur.com/QnlI8qp.jpg
#8
Posted 01 November 2022 - 01:06 AM
Quote
Hello.
The Polish EU07 Maszyna simulator is a fine example of this. One of the motors failed several times due to the increased line voltage. At that time, it was necessary to go into the engine room to switch off the failed engine and continue with three engines. Of course, the traffic always got in the way.
The engine compartment could be entered with the driver's position change function. Leading position, engine room leading position in order.
Sincerely, Laci1959
#9
Posted 01 November 2022 - 06:43 AM
2. Yes, that's so: untill regenerated voltage grow higher, than line voltage, no recuperation possible, so only rheostatic braking is available.
Later, automatic switch devices were introduced for activating recuperation or even switch between recuperation/resistors dissipation mode.
So, if no another consumers on same network's section - recuperation is harder to apply, as voltage in line is higher.
#10
Posted 01 November 2022 - 11:00 PM
Weter, on 01 November 2022 - 06:43 AM, said:
2. Yes, that's so: untill regenerated voltage grow higher, than line voltage, no recuperation possible, so only rheostatic braking is available.
Later, automatic switch devices were introduced for activating recuperation or even switch between recuperation/resistors dissipation mode.
So, if no another consumers on same network's section - recuperation is harder to apply, as voltage in line is higher.
For the older locos it looks like we would need to have the dc motor model as standard. Pluse we would need some additional meters for the cabview:
Line Volts = VOLTMETER ?
Motor Volts
Armature Amps = AMMETER ?
Field Amps
Also there would be additional or custom controls -
Series / Parallel Switch (See thread on manual transition)
Accelerating Lever = THROTTLE (but specific notch used for regeneration)
Regeneration Lever = DYNAMIC BRAKE
Rheostatic Brake = ? dynamic brake (Loco has separate rheostatic brake for low speed)