DR4018 Accessory Decoder used with eLink.

[Chrissaf]

As you say your post lacks useful detail.

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Looking at the DR4018 manual, the first thing that I see is that this device uses an external power supply to provide its operating power. This power supply needs a 2 Amp minimum current capacity with 3 Amp recommended (see yellow highlight in manual extract below).

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There is absolutely no mention in the manual of the DR4018 containing on-board 'Capacitor Discharge Units', this is supported by the fact that the current in the attached supply needs to be so high at 2 - 3 Amps. An accessory decoder with CDUs would only need a current of 100 mA (0.1 Amps) or so.

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In the manual extract images below....the DR5000 on the right represents your eLink controller.

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So the first question to ask is:

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Question 1) Does the image above represent how you have got the DR4018 physically connected? Are you using an external Power Supply? and does it meet the minimum 3 Amp recommendation (yellow highlight)? [EDIT: see my later post edit further below]

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Since the DR4018 power input can also be AC (the manual states that it has a bridge rectifier on board, and can use an AC power input). The second question to ask is:

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Question 2) Are you using the DCC track power on the power input terminals as well as the Signal input terminals. Such that you are using your DCC supply for both Signal (DCC) input and the DR4018 power supply connection? [EDIT: see my later post edit further below]

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If you are, then that is definitely the cause of your issue. As the standard eLink power supply is only rated at 1 Amp, so every time you operate a point. The DR4018 is trying to draw at least 2 Amps or maybe more. The eLink then sees this as a short.

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Even if you do have a separate external power supply. If it is not capable of providing the recommended 3 Amps of current (say for example, the supply you are using is rated at 1 Amp or less). Then it might be possible (subject to the internal electronic configuration of the DR4018) that the DR4018 is trying to supplement this current short fall by drawing more current through the 'Signal' (DCC track) connection. Again the eLink with the standard 1 Amp supply will potentially detect this as a short circuit condition.

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Personally, due to my my knowledge of electronics and AC to DC power conversion. I suggest that the quoted minimum recommendation in the DR4018 manual of 12 volts DC at 3 Amps is the absolute bare minimum and that the voltage should be higher than 12 volts for robust point motor operation. I suggest that the supply should either be 16 volts AC or DC at 3 Amps, not 12 volts. The manual states that the power is passed through a bridge rectifier. This will lose at least 1.2 volts, making a 12 volt input 12 - 1.2 = 10.8 volts available to operate the point motor subject to the electronics inside not dropping more voltage. A higher than 12 volts input voltage will ensure that after the internal DR4018 voltage drop losses are taken into account, there is still at least 12 volts available on the output to operate the point motor.

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In conclusion.

The bottom line, is that if the eLink is only being 'short circuit' triggered when operating a point. Then the DR4018 is trying to draw more current than the eLink can supply. Thus your issue must be one of power connection and specification (assuming no actual product hardware fault exists).

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EDIT: I should have read the rest of the DR4018 manual before creating my reply above. The power connection options in the manual section 6.0 are reproduced below:

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I deduce that you are using the middle option where the DCC supply doubles up as both power and signal input as I suggested might be the case in my original reply. This is never going to work with an eLink 1 amp supply.

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You need to use the first power connection option with the external power supply to resolve your issue.

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Before someone else suggests it....... yes you could upgrade the eLink 1 Amp power supply to the Hornby 4 Amp power supply. But even if you did that, you could still trigger the eLink short circuit protection if the ambient background train operating current is relatively high. The other issue I see with doing that, is every time you operate a point you are applying a high current demand on the eLink power system. Over time this can stress the eLink and could cause premature failure.

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It is far better and more robust to minimise the current draw on the eLink and offload high current demands to separate external power supplies.

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Note: see my recommendation about external power supplies in my original reply paragraph, directly above the 'In conclusion' heading.

[St1ngr4y]

Sounds plausible to me, Chris. However, just in case ....

 

Is the point an electrofrog and is it wired up to the decoder for "frog polarity switching" ? If so, then if the point motor is connected to the decoder but not physically attached to the point, then the frog polarity switch in the decoder will be the opposite to the point blades after operation, causing a short circuit. Probably not the case, but just a thought.

 

Ray

[Chrissaf]

Ray, he said that the point motors are not yet fitted to the point.

I havent yet mounted the Motors

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Plus my edit (published after your reply above) provides more supporting evidence for my theory.

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PS - the DR4018 does not have any 'frog switching' features built in. So any frog switching would need to be external contacts via the Seep motor.

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[Chrissaf]

Hi,

I've recently bought some Seep Motors (PM1) and a DR4018. I've wired them up and connected them, but every time i throw a point, the motor works but then the DR4018 short circuits and Railmaster asks me to clear it. I can't for the life of me work out why.

I havent yet mounted the Motors but I somehow doubt that this is why it's short circuiting but I'm happy to be put in my place!

I feel that this post is rather short and im probably missing detail but I can't think what else to put here!

Any help would be gratefull received!

 

 

 

[Pnosferatu]

This is why i love this forum. Even with the tiniest amount of detail, you solve my problem. I did have both power and signal wired to my e link. I shall buy a power supply now.

Thanks a lot guys!

[Chrissaf]

It is a common issue with Accessory decoders that do not have integrated CDUs and an external PSU instead. So a fairly simple deduction to make. Glad your issue resolution has been identified. Lets us know (for future reader information) the spec of the external power supply you install. I would suggest a cheap (on ebay) 15 volt DC >3 Amp laptop power supply. Normally I would suggest a 19 volt DC Laptop power supply, but on this occasion the DR4018 manual specifically puts an upper voltage limit of 18 volts DC.

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Selecting a different brand / model Accessory Decoder with integrated CDUs would have been a clear advantage to take, due to their much lower current supply requirement and more robust solenoid operating outputs.

[St1ngr4y]

Ray, he said that the point motors are not yet fitted to the point.

I havent yet mounted the Motors

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Plus my edit (published after your reply above) provides more supporting evidence for my theory.

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PS - the DR4018 does not have any 'frog switching' features built in. So any frog switching would need to be external contacts via the Seep motor.

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That was exactly my point, Chris. If the point motor wasn't connected to the point, then switching the decoder and therefore the built-in frog polarity switch (if it had one), would cause the unmoving point blades to produce a short. And my point still applies if the frog is wired up to frog switching on the Seep.

 

And by the way, I wasn't doubting your theory - I was simply providing a possible alternative.

 

Ray

[Chrissaf]

I was basing my comment on the assumption that if the point motors were not mounted on the point, that they were physically too far away for any frog connection (if there was one) to be made as part of the testing environment.