Kato N700S Motor Buzzing/Humming Sound

[Kotori]

Hello!

 

I am brand-new to this hobby so this might be a dumb question.  
 

I did my first run of a simple oval with a siding and Kato N700S Series rolling stock.  I noticed that when my power pack throttle was set to a low speed (low enough to keep the train idle with only headlights/taillights lit), and at speeds to have the train run slowly, the motor in the power car made a buzzing sound, loud enough to be noticed if you’re paying attention.

 

Is this a normal occurrence or is something wrong with my wiring/rolling stock?

[katoftw]

I am gonna say normal, as there is a low voltage electric motor in there. Especially is your a adding a voltage load that's not enough to get the motor spinning.

[cteno4]

Which throttle are you running?
 

Pulse wave modulation sources can make motors buzz at lower settings. Unless you are using a high frequency pwm source like Tomix cl transformers it’s not good to give a low level of power to just make the lights go on.

 

jeff

[Kotori]

@cteno4 It’s a basic Kato power pack, like what you’d find in an M1 set.

[cteno4]

That is a pwm power supply so it may cause some buzzing at lower outputs. Pwm causes some motors to really oscillate and hum until they are turning over at a good rpm. But usually Pwm will help motors turnover slowly and thus not jump from stationary to a faster speed.

 I don’t think that throttle has true high frequency Pwm for the stationary lighting.

 

jeff

[Kingmeow]

This is normal.  I recently was mucking around with that set as I installed a motor decoder and two light decoders.  But before I did that I ran it on DC before the decoders arrived.  The starter set was purchased in Japan when I was there on vacation in September and the add-on Set A was via a Plaza Japan order.

 

My throttle was an Athearn power pack which is a re-badged Railpower 1300.  It's a PWM power supply.  At low speed is does buzz and hum IF you pay attention and are looking for that sound.  It's not just the N700S but other DC locos that I have.

 

Don't worry about it, your set is running fine.