ateshci

The name is even known in Germany due to 'Midsomer Murders' of John Nettles' fame

Sure you can brew your own standards you adhere to on your layout and save a few millimeters ( or shall I say 1/32" ?), but if you want to take advantage of all available TT equipment, it is not a bad idea to adhere to the set standards

@Invicta Here are the relevant standards for clearance, and for the formation Cheers, H.

Never mind, the remainder is currently out of stock, too.

@BritInVanCA I have installed stay-alives in my HM7000 1st gen "Blink Bonny" ( of Scotsman fame) and "Night Hawk" after having had some funny experiences with BT before. Now I run them exclusively on BT and power the tracks with a 15V SMPS from an old laptop - no hickups, no need for DCC. Dead frogs are negotiated easily. Even the boffins can be wrong at times.

Standard TT-couplings depend on a rigid vertical mount to keep them horizontal. Many of the plastic close-couple holders are either distorted or are mounted in enclosures having too much vertical play when they move.

It's not a voltage doubler, but a full-fledged step-up converter that delivers 10V from an input of 5...1.5V, because the capacitor delivers the needed energy and is discharged therefore. The components on the decoder are a transistor to switch the charging current on/off ( I'm not sure whether it can handle more than 50mA ) and a reverse bypass diode into the motor/electronics supply to provide energy in case of contact loss.

Lest I forget -sometimes the hf current ripple ( same as the noise I referred to ) is too much for the decoder to tolerate. One can try to wire an inductor of 0.56mH ( maker: e.g. Delevan ) in series with the motor, as the resistive value of 4 Ohms is just tolerable @200mA and the additional space requirement of 8x11mm (dxh) can be tolerated in most cases. Sometimes even smaller inductors have helped, but that's a matter of trial and error ( or black magic 😀)

Use a screwdriver and gently pry it out.

Invoke stock alert, and ly back...(Things will happen while they can -'Big in Japan-Alphaville' )

A little late, but having used TOR-network via an Australian server one of the pictures looked like this:

This can happen when the motor is 'noisy' due to brush residue in the collector gaps. It will create current/voltage spikes then that hamper BT connection and may even upset the on-chip controller. A test would be to switch BT operation off and run by DCC - to show the severeness of the problem. If it stalls there too, a thorough cleaning of the motor is in order. In 'lighter' cases I've taken the motor out and ran it on 20..25V DC to burn the residue away - caution, you have to monitor the current draw. If it stays higher than 150mA for more than 30secs, the motor must be cleaned by other means, or may be faulty

They should work with every so equipped loco. Tillig had a hang for violating the norm in Plux-equipped locos, but that doesn't apply to Next18.

Still there's a misconception about the way most stay-alives work. There a few that use 10V...16V tantalum capacitors ranging from 100..1000 microfarad. The voltage drops by 10V during buffering and the time is rather short. All in all buffering in the milliseconds range. Then there's the majority delivering constant voltage for longer time intervals ( 2..10 secs) using step-up converters and supercaps. Lais' is one of them. Most of them use two supercaps in series to achieve acceptable COPs. These stay-alives are much better suited to support sound-decoders.

Sorry, the capacitors are rated 2.7V each. Please keep the facts correct.

The old DC controllers of the eighties won't do any harm to the decoders -they were variac transformers with out any electronics at all. ( Now don't name the then newfangled transistor throttles and the like, they existed, of course, but not on the average home layout )

Yet the final post: This is the charging circuit used:

Sorry for this one, but the editing time is just too short. When you take the quoted time of 1..2secs and the capacitor shown on the photo, you end up at an allowable maximal current consumption of motor and decoder of 5mA for a moving loco! So this claim is ...take your choice.

The photo shows one(!) SMD electrolytic capacitor rated 100µF/10V on a small pcb that contains the elements I have already shown in a previous post. Don't expect much of it - 100µF can store a charge of C=0.01Cb. Half of that can be used, because you start from 10V and your decoder will stop at ~5V. So that's 0.005Cb, which gives you a buffering time of t = C/I. Running light, your loco may draw 50mA, so the time t will be 0.01 sec and will be reduced to 0.003 sec under 150mA. Admittedly, in most cases it is just enough to overcome that loss of contact, but will be insufficient when crossing insulated point frogs at shunting speed. The price asked for it is - well compare with other offers. There are other makes around that start from 16V ( yes, there are SMD caps rated 330µF@16V ( e.g. Vishay 594D337X9016R2T, 7x7x3 mm³) and provide space for up to four in parallel -these are the ones that really just make sense in terms of ease of installing and space requirement. Anything in capacity <1000µF only provides marginal improvement and is wasted money IMHO.

The decoder's pcb has two pads( under the receptacle above ) labeled C+ and C- where one can attach a stay-alive with AWG 26 (0.14mm²) wire. This is an easy-to-find size.

I think I found what type of plug is used for the stay-alive socket : MOLEX 501330 0300. If I could only find one with wires already attached...

Just to set term usage right: 'Staco3' is the pcb (2nd photo, RH) that contains a step-up converter to supply a CONSTANT 10V taken from the small 0.3F 'supercaps' (2nd photo, LH). If two are fitted, they charge to ~5V. The effective capacity is 0.15F. The stored energy is 1.875 Wsec, of which according to ZIMO 1.2 Wsec can be used. Buffering time is ~1.5sec, which is fine to overcome even the worst dead spots. Charging time between two contact losses with total drain is ~30sec - so don't overdo shoddy track state! Here's an example of what I did, using a prismatic capacitor of 0.47F, later replaced by two 0.3F ones: The step-up converter sits vertically under the decoder.

So it's a rather bulky affair that charges to 8V. The rather simple regulating components ( one transistor, one or two resistors and a zener plus a reverse bypass diode ) are in the capacitor pack. The decoder just has a delayed switch to prevent the charging current from giving wrong acknowledge signals when programming. The usable voltage range is maximally just 3V , the decoder will not operate at less than 5V inner system voltage. So one can use <1.49 Wsec out of 10,56 Wsec that are stored in the capacitors. Take one of the step-up units, it could be hooked up the same way as Hornby's ( provided you find that Hirose or JST connector with wires already attached ) and you have 0.47F @5V, the usable voltage being somewhere in the 3V range again, and you get a constant(!) output of 9V..11V. The available energy is 2.1 Wsec out of 5.9 Sec at a space requirement of roughly 2/3. Even the unit that I use is more than sufficient to compensate for contact loss and it provides 10,5V for ~ 2secs. There are 0.7 Wsec out of 1.9 Wsec to be used. The one I use is small enough to find room even in the Arnold/Hornby HN9062 Koef, I have successfully installed more than one.

There was a UK website describing the 'Valdovia Rwy' ( now defunct ) and the builder used two of these in line, driven by an electric motor and carrying a roughly 6' long track ( it was 00 ) to have his trains travel from one tier to another. When talking TT, a 1m long bridge takes the same space in length as a reasonable helix with 45cm radius to keep the 2% per turn would do without the depth requirement. Taken the costs for material, I don't think there's much of a difference

The HM7000 BT IS compatible with a lot of other, and I daresay more sophisticated, stay-alives. As there's a sizeable capacitor involved, you have to provide some means of cutting the connection while programming via DCC. Sophisticated means a smaller capacitor ( usually only one or two operating @2.5..5V ) plus a step-up converter to use the capacity to its full extent. Buffering times of ~10sec under full load are not uncommon ( whether it is desirable to that extent is a matter of controversy, though ). Here's an example of how to do it