I would imagine that each DCC decoder could use a different algorithm to control the motor, from simple DC, to some mix of DC and pulse, to pure PWM. Does anyone know if different algorithms are used, and which is most common?
greg - Philadelphia & Reading / Reading
Contact a decoder manufacturer. I do know all decoders send only PWM to the motor.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
richg1998I do know all decoders send only PWM to the motor.
This makes sense since so many of the PIC controllers have pulse width modulated (PWM) controllers built in. Do the current generation of DC power packs also use PWM?
I had thought there were some issues with using PWM such as overheating and audio noise, or do these problems go away by using higher freq (100k) PWM?
gregcrichg1998I do know all decoders send only PWM to the motor. This makes sense since so many of the PIC controllers have pulse width modulated (PWM) controllers built in. Do the current generation of DC power packs also use PWM? I had thought there were some issues with using PWM such as overheating and audio noise, or do these problems go away by using higher freq (100k) PWM?
Some cheaper motors can buzz and coreless motors generally do not like PWM. Some older decoders operate at a lower frequency and can cause buzzing.
There are a couple DCC controllers that use zero bit stretching to operated DC only locos and the motors buzz.
Some power packs use PWM, some cheaper power packs use some of the AC taken before the rectifier for a "form" of pulse power.
Some people have tried to use a DC pack with pulse power to power their DCC controller that needs a DC voltage and the decoder did not like the response. Some DCC controllers can be bought without a DC power pack.
Below are some links that will describe DCC operation better than I can.
http://tinyurl.com/2fjpoya
http://tinyurl.com/22mmbpc
gregc Do the current generation of DC power packs also use PWM? I had thought there were some issues with using PWM such as overheating and audio noise, or do these problems go away by using higher freq (100k) PWM?
Do the current generation of DC power packs also use PWM?
Virtually any concerns go away at higher frequencies.
I use Aristo Craft Train Engineer wireless throttles and their output is high frequency pulse width modulation just like DCC. They work fine with both old and new DC equipment. They do not always work well with dual mode DCC decoders. I remove any/all decoders from all my equipment.
I am very happy with the performance of the Train Engineer throttles.
Sheldon
ATLANTIC CENTRALgregc Do the current generation of DC power packs also use PWM? I had thought there were some issues with using PWM such as overheating and audio noise, or do these problems go away by using higher freq (100k) PWM? Virtually any concerns go away at higher frequencies. I use Aristo Craft Train Engineer wireless throttles and their output is high frequency pulse width modulation just like DCC. They work fine with both old and new DC equipment. They do not always work well with dual mode DCC decoders. I remove any/all decoders from all my equipment. I am very happy with the performance of the Train Engineer throttles. Sheldon
I have seen kids running HO locos with the system Sheldon mentions and they had very good control and quiet locos.