So here's a question...I've got an MTH PS1 smoke motor installed in my Dead Rail converted, TCSWOW operated Bluerail engine I'm working on. The TCS has built-in chuff synchronization to match the audible chuffs using back EMF from the motor, so no chuff generator needed.
The TCS DCC decoder has two outputs for smoke: one output goes to the heater and the other goes to the fan. Both of these switch ground off a common output. I'm using a 12V power supply and the on board voltage ends up being around 9.8 at the output of the TCSWOW controller.
The PS1 smoke units are configured to run the fan constantly, and the coil as well. They are both powered from a single AC input on the smoke unit. My understanding is that the PCB has everything on board to send variable DC to the resistors (through a fancy transistor circuit that switches the heater to be in series or parallel depending on the input AC voltage) and then sends some of that through a regulating circuit that provides 5VDC to the motor (motor plugs into the onboard connector)
My plan is to unplug the motor leads from the connector and plug the positive right to the 9.2v output and the negative to the fan terminal on the TCSWOW, and send the 9.2V positive / coil ground right to the PCB AC inputs (I assume that the DC isn't a problem since it's just converted through a bridge anyway, right?)
I've tested all the outputs and even had the fan connected and the fan is blowing right it time with the chuff sounds. But my worry is that I'm sending ~9volts to the fan in a pulsating fashion (it's never continuous, and if I had to guess at the fastest chuff speed it's probably pulsing on / off at about 50% on time 50% off time over and over).
Is the 50/50 9.2Volt-0 Volt cycle safe for the 5V motor? My assumption is that over this duty cycle, it 'averages' 4.5 volts so it's maybe OK for the 5 Volt motor? (Like a crude PWM output for bigger DC motor controllers) Or do I need to send it through a regulator circuit? I'm running out of room in the boiler and I'm not sure if I can fit it. Or is there a fancy way to tap into any of the pins on the PCB for the smoke unit to send the 9.2V pulses through the internal regulator without messing with the heater circuit?
Does any of that make sense?
