Bachmann Online Forum

Discussion Boards => On30 => Topic started by: nglogger on March 12, 2007, 02:03:09 PM

Title: DCC in On30 Davenport - DC control?
Post by: nglogger on March 12, 2007, 02:03:09 PM
Hello,
I have a DCC-equipped On30 Davenport diesel, and I have a question about the DCC decoder. Is this designed for long-term use on a DC-only  layout? I was discussing this with a friend and he thought that long-term use of a decoder-equipped loco on straight DC might be harmful to the DCC board. Is there any official word from the Bach-man or others?
Thanks,
Joel
Title: Re: DCC in On30 Davenport - DC control?
Post by: Tim on March 12, 2007, 02:13:53 PM
Nglogger

It will do no harm to the decoder, it is designed to run on both
types of power.

If it disturbes you to run it with the decoder, remove it and install the
supplied jumpers.

Tim Anders
Souderton, Pa
Title: Re: DCC in On30 Davenport - DC control?
Post by: Tony Walsham on March 14, 2007, 08:52:34 AM
Just don't run it on a pwm type controller.

A pwm signal may "confuse" the decoder such that it can lose all programming, and in worst case situations actually damage the decoder.

Stick to a filtered linear type output.
Title: Re: DCC in On30 Davenport - DC control?
Post by: StanAmes on March 14, 2007, 03:18:47 PM
Tim

Quote
Just don't run it on a pwm type controller.

A pwm signal may "confuse" the decoder such that it can lose all programming, and in worst case situations actually damage the decoder.

The above information is not correct.  I have never seen any DC  PWM power source cause the type of decoder produced by Bachmann loose its programming.

So long as the max voltage of the supply is less then 24 volts DC the decoder will be fine.  If you find the DC pulses confuse the decoder, simply insert a capasitor across the DC outputs.

In general this is not a problem as the decoder is designed to work in DC mode.

Stan Ames


Title: Re: DCC in On30 Davenport - DC control?
Post by: Hunt on March 15, 2007, 01:46:41 AM
I encourage all NOT to use a PWM DC power supply with any duel mode decoder.

It does depend on the decoder; but more likely than not, PWM DC power will confuse any decoder. Some brands get confused less frequently than maybe some others.

An aside:
Sound duel mode decoders don’t get along very well at all with PWM DC power or open frame motors. If you install a  sound decoder…  use DCC power and a can type motor.
Title: Re: DCC in On30 Davenport - DC control?
Post by: Tony Walsham on March 15, 2007, 02:14:51 AM
What can I say?

I only build the stuff so what would I know?

Some pwm controllers have the ability to generate "spikes" of voltage greater than the input voltage.

So, unless Stan Ames is prepared to personally guarantee that any pwm controller will not "confuse" or damage any DCC decoder, Caveat Emptor.