Crosland

48 minutes ago, chickensoup said:

Going rate. 
 

Loco £545 

Sound £330

Weathering £75 

 

Ironically most modellers pay that and more. 

CS 

 

What decoder have you fitted? What's the rating of the decoder?

I seriously doubt a modern loco will draw anywhere near 5A under normal conditions.

The whole point of DCC is running multiple locos on the same track circuit. What happens when you add more locos? What capacity booster do you need then 10, 20, 50A? Sorry for being so blunt, but it's just ridiculous.

On a budget here with only one shot at a £995 locomotive

In that case I wouldn't be using EZ Command :) Stupidly high track voltage and very limited functionality!

Check the continuity between the bare wire ends and the tip and the two rings of the jacks then match them up.

The answer is in the Extended Packet Format Spec S-9.2.1 where it explains the addressing. Any address above 10000000 is followed by another byte to form a two-byte address, hence:

Addresses 11000000-11100111 (192-231)(inclusive): Multi Function Decoders with 14 bit addresses

So 14-bit (or extended or 4 byte or whatever you want to call them) addresses range from (stripping the top two bits, adding the second byte and switching to hex) 0x2000 - 0x27FF,  or 0 - 10,239. Some systems impose a limit of 0 - 9999 (hence refereed to as 4-digit).

They are 0.47 ohm resistors, used for current sensing. The fact they have released their magic smoke means that an overload was not detected correctly and the outputs were not turned off (or reversed) in a timely fashion. I would assume the MOSFETs for those channels are also damaged as they too will have had excess current through them.

As it's showing a short even with no track connection then it definitely loos like it's faulty. Please send it to us at the address on our website https://www.sprog-dcc.co.uk/contact and I will take a look.

Andrew

16 hours ago, AndyID said:

 

And adding diodes and rectifiers destroys any calibration the meters might have had which makes the values they present fairly useless.

If the meters are calibrated, they are calibrated. The diodes more or less cancel out. Perhaps a drawing will help.

The voltage applied to the RR will be two diode drops less than the supply. The voltmeter will read two diode drops less than the supply, i.e. the voltage applied to the RR.

There will be some inaccuracy due to the much lower current flowing through the voltmeter but it wouldn't be hard to bias the current through the lower bridge to even things out.

4 hours ago, cliff park said:

You could of course put a bridge rectifier in the voltmeter circuit. 

I think I suggested that on Sunday!

You can do something similar for the ammeter.

On 30/04/2022 at 17:33, Blue13 said:

Many thanks.

I'm asking as the bus wire is to thick to fit in the controller track terminals.

An inch or two of thinner wire to adapt to the terminals (as thick as the terminals allow)will be fine.

Its all about voltage drop, which will be negligible on such a short length.

For the ammeter, connect the ~ pins of a bridge rectifier in the feed to the rolling road and connect the meter across the + and - terminals. Current will always flow the same direction through the meter, regardless of the supply polarity. The voltage to the rolling road will be reduced by two diode drops.

For the voltmeter use another bridge rectifier with the ~ terminals connected to the feed and return of the rolling road. Connect the meter across the + and - terminals. Again, you will need to allow for two diode voltage drops when measuring the voltage.

Or strip less of the insulation and crimp it in the end of the railjoiner.

2 hours ago, DK123GWR said:

True, but every decoder I've used has taken an even value by default, and I was operating on the assumption that this one would be too. I suppose that if the loco is pre-owned a previous owner might have wired the decoder in reverse and already changed CV29 to correct the error.

Yes you will often get away with it, in a similar way that many people get away without following best wiring practices for DCC.

The real problem is that people see the advice to "add" or "subtract" and read across to other bits in CV29 which might already be set. Adding or subtracting will then cause a carry or borrow into the more significant bits, messing up other settings. That's when the fun really starts and is, I suspect, the source of other peoples issues with setting CV29.

1 hour ago, Michael Edge said:

I wasn't joking, I've seen alterations to CV29 cause all sorts of problems depending on which decoders and DCC systems are used, I prefer to keep it simple.

That's why the advice to "add 1" was corrected. If you use CV29 as it is intended there will be no problems.

1 hour ago, grriff said:

Not sure. DCC Concepts refer to them as large and very large.  They will keep the locos going for several seconds after loss of power. 

OK, The SPROG will generally cope with stay-alives but if they are very high capacitance and have no charge current limit the DCC signal may be upset for a short period. Sorry about that.

11 hours ago, John ks said:

The mA rating is generally the highest current the device can carry & to me doesn't indicate that there is a resistor present 

 

For LEDs it does (or, less likely, some form of semiconductor current limit). If there is nothing to limit the current through a LED then the current  will be a lot higher. Until the magic smoke escapes.

4 hours ago, grriff said:

Andrew

Both modes, but the problem seems worse in programmer mode (separate programming track SPROGII only) than command mode (main layout SPROG plus booster) 

David

How big are the stay alives?

On 03/04/2022 at 21:02, Nickey Line said:

One of the relays appears to have suffered a fatal burn-out!

Or the soldering iron got a bit close when making the modification.

The screw terminals look rusty!

On 02/04/2022 at 12:52, grriff said:

I have locos with DCC Concepts decoders and stay-alives which for some unknown reason suddenly move at high speed when the power is turned on (I have a SPROG) .

In programmer mode or command station mode?

On 02/04/2022 at 12:52, grriff said:

 

I've never found the reason but take care to only have one loco on the track while programming.

That's absolutely necessary in programmer mode, otherwise you will program every loco.

Is the Z21 the type of system that disables the layout when using the programming track, or does it allow you to continue running on the main layout whilst programming?

If the former then the Z21 is faulty. If the latter, it's very strange, but may still be a Z21 fault is programming somehow influences the main track signal.

On 03/04/2022 at 11:46, Yorkshire Square said:

 

That's very nice, but I note that your penny is not only out of scale, but out of era too. Heavens! 😆

Surely "Rule 1 Penny" applies here

I've had similar with parcels going the other way. Up and down the west coast for a week until it was finally delivered. At the time I put it down to the pandemic.

It sounds like the PSX trip level is too high and the power cab is tripping first which takes out all of the zones. 

Is there a visual indication that the PSX have all "tripped", rather than just lost their input?

Does the power cab indicate it has tripped?

If you disconnect the power bus from any one of the SCDs, does a short circuit on another power bus still cause all the SCDs to trip (even the one with no power bus connected)?

Conversely if you short the tracks together in the disconnected zone does it cause any tripping? If so, your zones are not as isolated as you think.

The offset pickup problem may be an issue if the boosters do not have common 0V connection. Digitrax call this "home ground". RFS mentioned this in an earlier post about Lenz systems. It should be explained in the documentation for each system.

In some setups the problem will be masked by the power supplies creating a common through the mains earth.

Do not create a common connection between booster outputs.

2 hours ago, grriff said:

I used the 12v output with a SPROG and it gave intermittent faults. I suspect the supply is far from pure, stable 12v and would only use it with components that can tolerate such a supply. 

Analog controllers of any sort or vintage are totally inappropriate for powering a SPROG!

9 hours ago, meil said:

The problem is the distant selling regulations.

They only apply to business sellers.