accsesory/ point decoder

Depends on which accessory decoder you want to use

You could use the ZTC 302 point motor/decoder in which case you would need 20 @£12.95 each not cheap, but it does include the actual point motor.

Team Digital SMD82 will operate 8 points and can be programmed to operate a route.

Hornby only 4 points

NCE snap it only 1 point.

There are alot more accessory decoders to choose from, not just these!

I think you may need to be a little more specific and which controller are you using?
Does it have the ability to control routes, do you want this function, if so the accessory decoder will need to be able to do this.

QUOTE (Vulcanbomber @ 29 Jul 2008, 19:45) <{POST_SNAPBACK}>Problem is most decoders won't switch more than one point motor, so if you have something like a 3 way point you are stuffed, I wish someone would bring out a decoder which would utilise a central CDU

Some of the accessory decoders do have on board CDU's and can switch more than one motor from one ouput.

Having tried to operate points using the DCC controller and with switches and indicator panel I prefer the later option.
Scrolling through and trying to remember point addresses can be a nightmare if there are loads, while also trying to control the loco with the same controller.

The only reason I can see to use the DCC to control the points is if they are in a hard to reach area and there are only a few to operate.
Or you are going for full PC control.
You still need signals or some sort of marker to tell you which way the point is set, so that still needs a fair bit of wiring.

Yes Heathcote electronics do make a little point indicator board which will give an output to an LED when it senses a current change, but what if the point sticks and doesn't actually move?? The indicator has sensed the current change so will change the LED, oops!

When I have another spurt to finish my OO layout I may use the Merg accessory decoders and the Encoder.
The Encoder uses on/off switches by operating these gives you an indication to which way the point is set, so you move a switch which will give the ouput to change the correct point motor.
The advantage being the Encoder can be in the mimic panel with the switches connected to it, as it works using DCC only two wires need go to the accessory decoders, which can be placed close to all of the points, reducing all of the wiring needed.
Plus this system can be on it's own separate DCC circuit, so any shorts and th epoints will still work.

Having said all of that the new CANBUS system that Merg are working on looks very interesting, and I may even go for that as it looks like it will make it even simpler to control and wire everything.

Just my thoughts and opinions having used different ways of controlling points, it's down to the individual and their own layout in the end.

*** A 3 way point requires the two solenoids to be independent not switched together - so no matter what you use you will need two sets of outputs.

The most cost effective multi-point decoder is the Lenz LS150 - its also the easiest to programme (Pauls digitrax is a good unit but unless you undertand CV use backwards, programming is a bit like trying to cook while reading a recipe in latin)

The big issue with changing multiple solenoids together is the abiity of the power supply - a peco PL10 for example has 4 ohm coils, so needs a momentary power of 4 amps at 16 volts.

Two will need 8 amps. THAT is why accessory decoders have problems, why you cannot use track power for solenoids and why many of you have problems with point motors.... high current needs big wire to connect things (32/02 for example) and big power supplies!

regards

Richard
DCCconcepts

QUOTE (Richard Johnson @ 30 Jul 2008, 04:54) <{POST_SNAPBACK}>The big issue with changing multiple solenoids together is the abiity of the power supply - a peco PL10 for example has 4 ohm coils, so needs a momentary power of 4 amps at 16 volts.

Two will need 8 amps. THAT is why accessory decoders have problems, why you cannot use track power for solenoids and why many of you have problems with point motors.... high current needs big wire to connect things (32/02 for example) and big power supplies!

All very true... but for completness it must be pointed out that the decoders with on-board CDUs get round most of these problems. Effectively they smooth out the high current for a very short time into a low current for a longer period. Hence you only need thick wires between the decoder and the point itself, you can have thinner wires back to the power supply which can also be much lower rated (or you could use track power).

My own experience is that the MERG accessory decoder throws two SEEP solenoids in parallel and is perfectly reliable provided the SEEPs are aligned correctly (which I find a bit tricky).

Another factor influencing the number of decoders is the physical distribution of the points. If there are many close together than it probably saves space and money to drive as many as possible from a single decoder. However if a point is geographically isolated it might be better to position a single-ouput decoder nearby to avoid a long wiring run which for a solenoid would need to use some heavy gauge wire.

QUOTE (Edwin @ 30 Jul 2008, 15:47) <{POST_SNAPBACK}>Hence you only need thick wires between the decoder and the point itself, you can have thinner wires back to the power supply which can also be much lower rated (or you could use track power). .

***Sorry... but yes, a local CDU to each point helps but that is simply not true as a general comment. light wire for power applications is never a good idea and shouldn't be encouraged. You cannot change the laws of physics. when the distance is longer the need for wire gauge remains. terms like "lighter" are also dangeous to use, as modellers tend to use too light wire often!

It is also NEVER a good idea to connect accessory devices to the track bus for power supply purposes, as this leads to loading of the track bus and also contributes to a disturbance of the control waveform that causes control issues that increase in proprtion to the complexity of the layout.

A separate accessory power bus should be run for point decoders wherever possible - and that is always as long as one is willing to do the added installation

Richard
DCCconcepts

QUOTE (Marek Klimczyk @ 31 Jul 2008, 07:41) <{POST_SNAPBACK}>Did anyone try a new ESU SwitchPilot? It has only four ports as opposed to Lenz LS150 6 ports, but it has feed back and can control to servo motors.

Price per point is almost identical give or take 20 pence.

Regards,
Marek
Yes, I tried it when it first came out and dropped it in favour of the LS150 for a few reasons. Cost was one of them, the fact that it only controls snap action point motors, unless you buy the Switchpilot extension which then doubles your cost for four slow motion motors. The difficulty in programming, and lets face it, relative to the LS150 and the LDT S-dec-4 it is a major hassle. There was also the problem at the time that only German instructions were available however you can get English instructions easily now from their website. It is worth looking into if you use snap actions but not if you use slow motion.