Alternative to cherry switch in TMCC diesel with railsounds?

Well, I could stick my Chuff-Generator on the flywheel and program it to output pulses based on the speed of the motor.  I actually do this on my TMCC testset to generate the pulse output for testing RailSounds boards.

Another way would be to come up with a simple board that takes the PWM output from the R2LC.  The two PWM outputs controls motor movement and direction.  There is no output when the motor is stopped.

There's also the magnet on the wheel and a reed switch switch, the time honored way of doing chuffs on a steamer.

Digital Dynamics offered what the called a "chuffer board" that was connected to the field coil of a AC motor or the terminals of a DC motor and it generated pulses based on voltage. They are of course no longer available. I wonder if I can get a schematic of that board somewhere.

Never saw that one, though I recall it being mentioned before.  Schematics are the impossible dream for any of that stuff I suspect.

Driving stuff off the motor voltage is a bit tricky, the connections to the motor must be totally isolated.

I'd probably consider something like the Vishay IL300 Linear Optocoupler across the motor with a reverse polarity Schottky protection diode bridge and current limiting resistor.  That would isolate the motor voltage and give you a variable DC voltage based on motor voltage.  A cheap PIC processor could easily input the voltage and generate a pulse based on the output from the IL300 to trigger the diesel ramp-up/down.

@gunrunnerjohn posted:

Never saw that one, though I recall it being mentioned before.  Schematics are the impossible dream for any of that stuff I suspect.

Driving stuff off the motor voltage is a bit tricky, the connections to the motor must be totally isolated.

I'd probably consider something like the Vishay IL300 Linear Optocoupler across the motor with a reverse polarity Schottky protection diode bridge and current limiting resistor.  That would isolate the motor voltage and give you a variable DC voltage based on motor voltage.  A cheap PIC processor could easily input the voltage and generate a pulse based on the output from the IL300 to trigger the diesel ramp-up/down.

Which makes me wonder how the chuff was generated on the K Line cruise motor driver board.

@cjack posted:

Which makes me wonder how the chuff was generated on the K Line cruise motor driver board.

Pretty sure they counted motor tach pulses just like Legacy, MTH, TAS EOB does. I am curious why a switch is even required. Is this something unique to Pullmor diesels? I have never seen one on a DC motor diesel. Prime mover ramp up is driven by a VCO in conventional.

Pete

@cjack posted:

Which makes me wonder how the chuff was generated on the K Line cruise motor driver board.

Like Pete says, they just count tach pulses, easy peasy.

@Norton posted:

I am curious why a switch is even required. Is this something unique to Pullmor diesels? I have never seen one on a DC motor diesel. Prime mover ramp up is driven by a VCO in conventional.

Pete, RailSounds 4 an earlier didn't have any way onboard to manage diesel ramping.  The VCO has to be somewhere, and it's not on the sound board.  On certain Lionel motherboards, it's actually included.  The Diesel version of the TAS boards also had a VCO on-board.  As you note, on many Pulmore equipped engines it was a switch on the truck.  The Lionel DCDS has a DUTY output for diesel versions, that's their pulse to manage the diesel ramping.  The ERR Odyssey version of the Cruise Commander M also outputs the DUTY signal instead of repeating the serial data as the generic Cruise Commander M does.

Recall that early RailSounds for diesels often came in a dummy 'B' unit, separate from the powered 'A' unit.

I have the Santa Fe Freight F3's (Blue/Yellow), which we're sold this way.  The 'B' unit (6-18122) has one truck fitted with a magnet on an axle, and a hall effect sensor, to provide the motion signal.

Also found the same sort of way on NYC Alco PA's for which the RailSounds 'B' unit is 6-18966.

Also check any SuperBass 'B' unit.  Same idea.

Mike

I forgot about the SuperBass units.  However unpowered units are a different situation as they don't have the motor drive serial data to tell them that they're moving.  A Legacy diesel doesn't have any switches as the electronics can signal when the motor is being driven.

Actually on the superbass units you’d think they wouldn’t need any input but actually there is a Hall effect sensor on the axel of my E7 SuperBass and the tender of my Veranda.

Never made since to me but good information for everything else TMCC related 😉

I'm guessing the hall effect sensor might be for conventional operation?

@gunrunnerjohn posted:

I'm guessing the hall effect sensor might be for conventional operation?

Ha, good point.

I tend to forget about conventional on a full command equipped locomotive 😉

@Mellow Hudson Mike posted:

Recall that early RailSounds for diesels often came in a dummy 'B' unit, separate from the powered 'A' unit.

I have the Santa Fe Freight F3's (Blue/Yellow), which we're sold this way.  The 'B' unit (6-18122) has one truck fitted with a magnet on an axle, and a hall effect sensor, to provide the motion signal.

Also found the same sort of way on NYC Alco PA's for which the RailSounds 'B' unit is 6-18966.

Also check any SuperBass 'B' unit.  Same idea.

Mike

Early TMCC GP9s also have a cherry switch on one axle to signal to the Railsounds board that the locomotive is moving.