I've got a Rokuhan 'shorty' layout, SS002-1, and I'm looking at adding remote control operation with an Arduino. To this end, I'm looking at using a L298N motor driver module, which I have lying around, to drive the track. The thing is, this particular module is known to have issues driving motors on a supply of less than 5v. I understand that the Rokuhan motors run at a maximum of 3v. Given that this motor module outputs PWM, I was wondering if it would be safe to run it at 9v, with a resistor in series between the output of the L298N and the track? On a related note, I'm also going to be using a DPDT relay to control a R022 turnout set. Is it safe to leave this powered when it's not changing direction, or would it need something like a capacitor discharge unit?
Hi Danny, welcome to Trainboard's Z Scale Forum. Short answer YES. But you need to add a 220-330Ω resistor in series with one of the motor leads. Then it can take 9-12V of PWM just fine. I use a circuit on my shorty drives that adds Zener diodes and resistors the make constant intensity directional lighting as well as 12V PWM motor compatibility. I'll search for the schematic when I get out to the garage. As far as the R022, NO CONSTANT POWER ALLOWED. The reason is the coils of super thin wires will get hot and melt in a few moments. Their coils can only take momentary spikes of power. You would be better off using a capacitor discharge circuit and triggering it with a digital output for 20-50 milliseconds or so.
Thank you, that will be useful. For the turnout, what's the maximum voltage they can use for throwing? I've taken a look at CDUs, and most seem to need at least 15v. Except for one with a pre-voltage module that steps the input up to 26v. This strikes me as a bit excessive.
You should be able to use 12V. I bought DS52 Dual Stationary Decoders for Snap Switches because I use DCC, but if I was going to use an Arduino to throw the turnouts, I would use something like the ELEGOO 4 Channel DC 5V Relay Module with Optocoupler Compatible with Arduino UNO R3 and test the turnouts for reliable operation with something like a digital output only on for 20 milliseconds, and increasing only up to 100ms max so you don't have 12V on the turnout solenoids too long. The Rokuhan turnout solenoid is much smaller than any in the other scales, so should throw with authority at 12V for a very pulse time.
