HM7000 Power Bank - Power

[PeterStiles]

I have one loco loaded up with a HM7000 Hornby TXS sound and Power Bank.

I ran it round the temporary layout (I don't have a permanent DCC layout (as yet) ) and was reasonably pleased, although lacking Apple gear I was just treating it as a normal DCC decoder.

I switched everything off and started packing away when I was surprised to hear a hissing noise and I looked around and realised I'd left the loco sound "on" and so it was idling.

I stared at it, and it kept hissing gently. I packed everything away and picked the loco up, still hissing, and boxed it up, and shelved it... still hissing.

 

It took over _30_ seconds from power-off to the sound finally stopping. I should have measured it but I wasn't expecting it.

 

That's way over the 12 seconds the marketing said we'd get; however I suppose it was only driving a speaker and some chips, and no motor involved, but in any world that seems like one hell of a stay-alive.

 

 

[Ron Ron Ron]

Some stay alive are designed just to give a couple of seconds of power, to overcome momentary breaks in the track power, such as going over a bit of dirt, or the wheels momentarily losing contact with the track.

 

Other designs, like those from TCS, provide a longer period of backup power supply.

Hornby's Power Bank appears to be in the latter camp.

 

 

.

[RAF96]

You will get 9 seconds of motor drive, sound only is much more and lights only is very much more. 3 x 1F super caps wired in series. The only fault I find is they only charge when the loco is moving so if starting a new day from a station platform over dead points onto the main line the loco can stumble. It has been suggested that static or mobile charging is made an option by way of a CV setting. One problem may be in-rush current to the power banks tripping a controller if many equipped locos are on track.

[Merlin242]

I have 7 decoders all fitted with the power bank. 4 are relatively new (Princess, 4MT, Hardwick, Clan) these operate faultlessly all the time.

The 3 older locos (2 Fowler2-6-4  tanks, Ivatt 2) all have the same issue. On first using them the with sound on the loco starts for part of a wheel revolution then the decoder trips out. Resets and tries again usually this happens 2 -4 times. Then after that they work fine all the time for the rest of the day and sometimes the day after.

My solution is to switch off the sound on first using it which helps and if I remember in time use the plus key to start the motor control to 1 or 2. The loco wont start but the power bank slowly charges. After a couple of minutes doing that the loco will start normally and will run fine for the rest of the day. This is almost a throw back to the TTS decoders which have the same issue sometimes  even worse especially I found the Black5 with the older models.  Those decoders had a lower power rating and the older engines do use more power. Ideally the power bank would be allowed a trickle charge when not running which would get over this problem and also avoid programming errors. I always now first set up the decoders without the power bank installed. 

[RAF96]

There were a couple of reasons the power bank was defaulted to dynamically charged. 
1. Out of circuit to ensure programming was not affected.

2. When the ASU (atomising steam unit) is released the combined in-rush of that and a power bank would be too much for most controllers.

I think the final solution will be a CV switch that allows for static or dynamic charging of the power bank dependant upon either user option or default kit fitted to the loco (ASU /no-ASU). 
I like the speed step 1/2 to ‘trickle’ charge it though.

[GraemeWatson]

Esteemed RMWeb members, I wonder if anyone has tried fitting the Hornby power bank to a Gaugemaster ruby decoder? The Hornby product has the same plug arrangement as the Gaugemaster stay alive designed for their Ruby decoder range, but I wonder if anyone has tried them for cross compatibility (all the documentation says not to, of course). 

[spamcan61]

13 minutes ago, GraemeWatson said:

Esteemed RMWeb members, I wonder if anyone has tried fitting the Hornby power bank to a Gaugemaster ruby decoder? The Hornby product has the same plug arrangement as the Gaugemaster stay alive designed for their Ruby decoder range, but I wonder if anyone has tried them for cross compatibility (all the documentation says not to, of course). 

I think 'RAF96' pointed out a while back that the Hornby power bank actually has some of its circuitry on the decoder as opposed to the power bank itself, so isn't interchangeable with "normal" power banks.

Edited July 21, 2023 by spamcan61

[SteveM666]

3 minutes ago, spamcan61 said:

I think 'RAF96' pointed out a while back that the Hornby power bank actually has some of its circuitry on the decoder as opposed to the power bank itself, so isn't interchangeable with "normal" power banks.

That may or may not be the case, but I have successfully fitted some to TTS decoders without any problems. No idea about the Ruby though.

[GraemeWatson]

7 minutes ago, SteveM666 said:

That may or may not be the case, but I have successfully fitted some to TTS decoders without any problems. No idea about the Ruby though.

Useful to know.

The potential attraction with using the Hornby Power Bank is that it is a surprisingly useful size, compared to Gaugemaster's own stay alive.

If it turned out to be a like for like replacement, that would be useful.

 

[RAF96]

Look at the mechanics of the Hornby power bank , it is three 2.7 volts super caps in series, so  establish what voltage on your decoder you are connecting to the that.

The Hornby decoders have a zenner and resistor between the bridge rectifier and the power bank feed to control power in and allow power out.

Edit - also take the shrink wrap off the power bank and you will see it is not just the normal 1 x resistor and 1 x diode charging circuit.

Edited July 22, 2023 by RAF96

[Wayne Bridgman]

As Hornby have run out of the HM 7070  Power Banks has anyone tried to put a Lias DCC Power Bank on a HM 7000 Chip and do you know what the plug is or the website id like to try this out . 

Edited March 25 by Wayne Bridgman

[ColinB]

1 hour ago, Wayne Bridgman said:

As Hornby have run out of the HM 7070  Power Banks has anyone tried to put a Lias DCC Power Bank on a HM 7000 Chip and do you know what the plug is or the website id like to try this out . 

I keep thinking of trying it. After I got castigated on the Hornby Forum at the mere mention of a LaisDCC stayalive, I am tempted to try it to see if it works. Trouble is get it wrong and you have blown up a HM7000. I suspect they might be the same hardware, but without a lot of work I don't really know. If it is a 21 pin socket you can always connect it between the VRef and Ground pins on the socket.