Decoder chips burning out (or not) ?

[ColinB]

To be honest I used to watch a lot of Jenny Kirk's reviews until she did one on the Hush Hush, the original version. After she had said what a good loco it was, and my one had a big issue with the front bogie being too high, she lost all credibility with me. Dear old Barry said the same, then much later when the fixed one came out, informed us that he sold the original as it was so bad. At least Sam pointed out that there were issues, over dramatically, but he was right. I suspect on all subsequent versions they fixed that front bogie, my rebuilt ones have no such issues and Hornby tell me that they all use the same chassis although they may well have done a tweak (been there done it). As to the devices burning out, well seeing as the Android app is not available yet perhaps most are like mine, sitting in a loco waiting for the app to magically appear. How long is it now?

[Fishmanoz]

Sigh. Listen to the Fish. I have given up.

 

 

Given this reaction, I’m deleting my post except to say I agree with RAF on the practical limitations in paralleling supplies, and:

@Pendragon, I can’t see a good reason for you to go beyond your existing supply for now. The 4 Amp unit is a well-proven and capable unit with enough power to run more locos at the one time (up to 10) than you can keep in your head without having head-ons. I see no reason to spend more now for an extra ampere.

[Daedalus]

[dBerriff]

No, Fishy, please leave your post - it was spot on. “Listen to the Fish” was meant to be in the imperative sense - listen to you because you speak good sense. Edit: my post now deleted because it makes even less sense without your post.

Regarding our other correspondent, I am reminded about the old visual joke of a body on a slab. One arm is sticking up. Push down the arm, a leg pops up. Push down the leg and the other arm pops up. Push down the arm and the other leg pops up. And so it goes.

Over and out.

[Pendragon Sailing]

Sigh. Listen to the Fish. I have given up.

Given this reaction, I’m deleting my post except to say I agree with RAF on the practical limitations in paralleling supplies, and:

@Pendragon, I can’t see a good reason for you to go beyond your existing supply for now. The 4 Amp unit is a well-proven and capable unit with enough power to run more locos at the one time (up to 10) than you can keep in your head without having head-ons. I see no reason to spend more now for an extra ampere.

 

 

Thanks for the advice @Fishmanoz…much appreciated

[Daedalus]

[Fishmanoz]

Sorry dB, yes I did misinterpret you and now not about to type it all out again. Even checked to see if it stayed in my posting record, as do posts from deleted threads, but no, it’s gone.

Mods, might I suggest you check whether there is a problem here that needs some action?

[dBerriff]

I seem to have lost the ability to express myself clearly so my fault. disappointed

[dBerriff]

As I seem to have derailed this thread, I will try to get the basics back on track. So, with HM7000 decoders, to the best of my understanding for a small domestic layout:

• using a recommended Hornby DCC power supply is ok.
• using a Hornby Select or Elite DCC controller as a power supply is ok.
• using other DCC controllers of reputable make should be ok.
• using certain analogue (DC) controllers appears to be NOT ok. So for now, do not use ANY kind of DC controller to power the HM7000 decoders.

If I have got this wrong I am happy to be corrected by the mods or Fishy.

[Fishmanoz]

Perfect dB.

[HST Mainline]

HST, that sounds more like a bent terminal inside the connector on the power track and the two strips are touching. If the button is not depressed when inserting the pins, enough force can distort the connector strips inside. DCC should not be wired via a DC power track connector because there are components inside to comply with radio wave interference regulations that can distort a DCC signal sent through the track.

 

 

I took my power track apart to check on the terminals inside. It could be that you are right, the connectors are very close to the bridge between the two. My assessment is that it would be possible for the connector to cause a short when the power plug is inserted.

I have removed the bridge, because I do not need it anyway with DCC. Everything works now.

Thank you for your advice.

[Fishmanoz]

By bridge, I assume you mean the RF interference suppression capacitor?

And just to be clear, if all you are doing is connecting DC or DCC to the track to power Bluetooth operation, it is irrelevant whether this capacitor is removed or not. It only needs to be removed for legacy DCC operation where not just power but DCC signals are sent through the track. It is the signals that the capacitor interferes with.

[HST Mainline]

Correct, it is basically the only thing that bridges the terminals inside the little box. I just was not sure about the terminology for it.

I use the track for both the HM7000 and DCC operation. So I needed the capacitor to go - or buy a digital version of the power track.

Since I noticed that there was a slight chance that, when connected, the "cobber springy things" could touch the opposite solder pad of the capacitor, I removed it alltogether. I also removed the exces solder remains for a clean and trouble free circuit.

As mentioned earlier I did have weird shorts on the track that I isolated to be caused by the power track. Those problems are gone now, so the advise given here has helped.

In the end: It was not the decoder and that is good!

[Fishmanoz]

Good to know HST.

Advice to remove the capacitor to make DC power tracks DCC compatible has been around for years (in the DCC forum FAQs for OO with pictures). Similar for TT:120 although the cover doesn’t just flip open, needs the lugs to be disengaged.

Yet to do mine as I’m using the app and the power track is short term until the layout is built (if track is available in Aust anytime this century!).