DU202 vs DU204 controllers

[ronin]

Looking for any info on what the differences are between these 2.  Visually they look pretty close, but I am assuming there are some differences.  Can anyone enlighten me?

 

Thanks,

Eric

[kvp]

One rather big difference is that the du204 has an external power adapter, so it's usable anywhere in the world by getting a proper localized adapter, while the du202 has a built in japanese 100V transformer and can not be safely used even in the USA, where the wall power is 110V. Getting a properly rated 110V AC to 100V or 240V AC to 100V converter is harder than buying a local power to 12V DC wall wart.

[JR 500系]

5 hours ago, kvp said:

One rather big difference is that the du204 has an external power adapter, so it's usable anywhere in the world by getting a proper localized adapter, while the du202 has a built in japanese 100V transformer and can not be safely used even in the USA, where the wall power is 110V. Getting a properly rated 110V AC to 100V or 240V AC to 100V converter is harder than buying a local power to 12V DC wall wart.

 

oohhh... this is actually usefully for me too... but too bad I already have the DU202... and a HUGE step down transformer... with the DU204 the transformer is not required....

 

Oh well... I guess i'll stick with the DU202 for now, but maybe getting the Taiwan controller instead to play!

[ronin]

Thanks for the reply.  Sounds like the power adaptor is the main difference so far.  Operationally they are the same or similar.

 

I have just run across a DU201.  Looks the same as the 202.  Any thoughts on that one?

 

Thanks again,

Eric

[Welshbloke]

I had an idea while reading about the dangers of vintage model train transformers (60 year old insulation and 240v not being a good mix) which might help here.

 

The transformer inside the case provides a 12v DC output. So it should be possible to open the case and bypass it. Fit a 12v input socket where the old mains cable went in and connect it in place of the output side of the transformer, then buy a new external power supply which turns your local mains voltage into 12v DC. It will be slightly more complex if a controller has 16v AC accessory terminals but the basic idea should still work. The disconnected original transformer can be kept as ballast to stop the controller sliding around, just make sure it's completely isolated.

 

I did something similar with a spare 12v wall wart and a cheap PWM control board from ebay. Added a switch to reverse polarity and it works perfectly with excellent slow speed control and no signs of overheating.

[kvp]

43 minutes ago, Welshbloke said:

The transformer inside the case provides a 12v DC output.

More or less. It's completly possible, that the old circuits need something around 14V DC or so to be able to output 12V DC, but removing the high voltage side of the circuit and replacing it with a wall adapter is probably possible. One thing to look for is isolation, as old transformers provided a floating ground on the low voltage side, allowing multiple controllers to be used together. Modern wall adapters and wall adapter using controllers (especially pwm based ones) are prone to have a passthrough ground, where the inputs and outputs are galvanically connected. This means they must be run from the same distributor strip and turned on and off at the same time. (preferably with a switch on the power strip). Also transitions between two independent pwm controllers should be avoided. Tomix provides great controller switch over circuits that allow this, so two controller outputs are never connected, not even by the wheels of a train.

[Welshbloke]

4 hours ago, kvp said:

More or less. It's completly possible, that the old circuits need something around 14V DC or so to be able to output 12V DC, but removing the high voltage side of the circuit and replacing it with a wall adapter is probably possible. One thing to look for is isolation, as old transformers provided a floating ground on the low voltage side, allowing multiple controllers to be used together. Modern wall adapters and wall adapter using controllers (especially pwm based ones) are prone to have a passthrough ground, where the inputs and outputs are galvanically connected. This means they must be run from the same distributor strip and turned on and off at the same time. (preferably with a switch on the power strip). Also transitions between two independent pwm controllers should be avoided. Tomix provides great controller switch over circuits that allow this, so two controller outputs are never connected, not even by the wheels of a train.

Yep, I know Marklin say not to connect more than one controller to the same track section for that reason (unplugging one would leave you with about 240v on the plug pins as the transformer would turn into an inverter, turning the 16v AC back into mains voltage).

 

I saw some old Kato controllers a while ago and would probably have bought one to modify, but despite having a 100v input and therefore being useless in the UK they were being sold for almost £30 each! After buying the new transformer and a low voltage socket a brand new UK spec controller would be about the same price...