ECoS, SwitchPilots and two PECO point motors at a time

[Waverley West]

Hi all,

 

After my decision to abandon ZTC, I have recently invested in an ECoS system and a couple of Switchpilots to try them out with my Peco point motors. 

 

Having set up the ECoS, I have been trying to get one of the Switchpilots working with my point motors and am now at my wit's end trying to get the Switchpilot to switch more than a single Peco motor at a time. This seems to be a recurring problem for many modellers trying this combination and I've had a good search both here on RMWeb and elsewhere. Just about everyone seems to have overcome the problem of getting the two to work together and, as far as I can see, I have done everything necessary to get them working:

 

I have installed a separate power supply and tried it at voltages from 12 to 24 V DC.

I have set CVs 3,4, 5 and 6 on the Switchpilot to 1, as recommended in the Switchpilot manual for PECO motors.

I have also tried various durations for the pulse, including everything from 250 to 750 mS.

I've connected up the Switchpilot to the programming output using a resistor and read back all the relevant values and they seem OK.

I've set the addresses of the four outputs to 9, 10, 11 and 12 (in "Create/edit accessory") and the address of the decoder itself as 3 on the programming output (that's right, isn't it?). Addresses 1 to 8 are currently used by my ZTC 304s, so I wanted to start at 9 in this case.

 

The single point motors work OK and switch the point fairly reliably, assuming a little time is left between each switch. But I've also wired up a crossover with two points/motors and the Switchpilot can only throw one. I have tried switching the one that doesn't work on its own and that works fine, so there is nothing wrong with the point motor itself. 

 

From what I've read on't internet, with a decent separate power supply and the CVs altered appropriately, I shouldn't have any problems throwing two or more motors at once.

 

Right now, I don't have any more ideas as to what I can do, apart from trying the low current motors, but reading on the internet suggests this really shouldn't be necessary with a properly set-up system. I think I do have a couple of those motors so I could try them. It seems like quite a few other people have experienced the same problem but managed to solve it by doing what I have done but it doesn't seem to work for me, unless I am missing something!

 

As I've got the best part of 40 motors, I'd really want to get my current set-up working as it is, rather than having to replace all the point motors with low current versions or other motors, especially as the evidence I have found on the net suggests the system I have now should work OK.

 

Any ideas or thoughts you may have would be very welcome! 

 

Cheers

An incredibly frustrated Waverley West (Dave)

 

 

[Phil S]

Have you experimented with adjusting the spring tension in each of the Peco Points - slide the retaining bar away from the the tie bar a small amount, to lower the tension in the over-centre spring.

Also, check of course, that nothing (eg ballast or PVA adhesive from ballasting) is interfering with the free movement of the point blades and below-track components.

 

Back in Zero-1 days, when I still used Peco points; I wired the point motors in series (2 wires between the respective coils in each motor) to successfully reduce the excessive currents taken by the 'brute force and ignorance' design of the Peco point motor (it makes no attempt to use mechancical advantage) - and adjusted the spring tensions as required.

 

(If you have bouncing Peco points - this might be because the over-centre spring has become misplaced, or weakened)

[Waverley West]

Hi Phil,

 

I don't think there's too much wrong with the point in the crossover set-up that doesn't move. If connected up on its own, it switches easily enough and it never used to cause any problems with my old ZTC set-up. 

 

I'll definitely have a look at the spring though and see if I can move the retaining bar away from the tie bar as you suggest. Thanks.

 

Cheers

Dave

[GoingUnderground]

SwitchPilots are best teamed up with the Peco lower current Green Coil PL10w solenoids.

[Waverley West]

SwitchPilots are best teamed up with the Peco lower current Green Coil PL10w solenoids.

 

Hi Keith,

 

Yes, I had heard that. It's just that I had heard of many people successfully using the standard Peco motors with Switchpilots powered from a separate power supply. I can go done the low current route, but that would mean replacing 40-odd perfectly functioning point motors.

 

Cheers

Dave

[GoingUnderground]

I think you'll be lucky to get it to throw 2 or more red coil PL10 ones at the same time. You could use your old accessory decoders (ZTC 304?) with your ECoS, they should work (famous last words), there's no need to change to SwitchPilots just because you have an ECoS.

[Waverley West]

I've tried connecting up my ZTC 304s to the Switchpilot with mixed results.  Of the 6 I wired up (identically), 3 worked fine and the others either worked intermittently or not at all. I wired up a separate power supply for these too. The mixed results I got were why I wanted to try the Switchpilot as a trial. 

 

I could try fitting the low current motors to my crossovers only for a start. That might work as a compromise, but I really don't understand why there isn't much of a kick on the motors when I'm applying (up to) 24V DC to them. I've checked the voltage on the Switchpilot terminals too, so I know that voltage is getting through to the Switchpilot at least and I'm pretty sure I've overridden the current limiter on the ECoS by setting the appropriate CV values.

[GoingUnderground]

I've tried connecting up my ZTC 304s to the Switchpilot with mixed results.  Of the 6 I wired up (identically), 3 worked fine and the others either worked intermittently or not at all. I wired up a separate power supply for these too. The mixed results I got were why I wanted to try the Switchpilot as a trial. 

 

I could try fitting the low current motors to my crossovers only for a start. That might work as a compromise, but I really don't understand why there isn't much of a kick on the motors when I'm applying (up to) 24V DC to them. I've checked the voltage on the Switchpilot terminals too, so I know that voltage is getting through to the Switchpilot at least and I'm pretty sure I've overridden the current limiter on the ECoS by setting the appropriate CV values.

 

The CVs that you have changed are on the SwitchPilots and are nothing to do with the output of the ECoS. You can limit the ECoS current output, but you do that from the ECoS's configuration menu or it might be the booster menu, sorry can't remember which it is. But if you are using an external power source then it doesn't matter as the power for the SP and the solenoids will be coming from that. 

[Suzie]

The switchpilot manual indicates that it is good for 1.5A. Since the standard Peco motors will require 4A each, with a pair on a crossover requiring 8A you are rather pushing it a bit to get them to move. This is why Peco produced the PL10W which should be within the current rating of the switchpilot being much more efficient.

 

Putting the motors in series should help a bit by reducing the current requirement to 2A and you will get even share of the power between the two motors, but you will need to ensure that the motors are accurately positioned, the springs adjusted carefully to just hold the tiebar in place and the motors will need lubricating since they will be getting less than a quarter of the power they are designed for.

 

If you don't want to replace the motors or change the wiring it will be worth looking for 8A capable decoders which are rather thin on the ground.

[Waverley West]

The CVs that you have changed are on the SwitchPilots and are nothing to do with the output of the ECoS. 

 

 

That's what I meant Keith. Sorry, I wasn't very clear.

[Waverley West]

The switchpilot manual indicates that it is good for 1.5A. Since the standard Peco motors will require 4A each, with a pair on a crossover requiring 8A you are rather pushing it a bit to get them to move. This is why Peco produced the PL10W which should be within the current rating of the switchpilot being much more efficient.

 

Putting the motors in series should help a bit by reducing the current requirement to 2A and you will get even share of the power between the two motors, but you will need to ensure that the motors are accurately positioned, the springs adjusted carefully to just hold the tiebar in place and the motors will need lubricating since they will be getting less than a quarter of the power they are designed for.

 

If you don't want to replace the motors or change the wiring it will be worth looking for 8A capable decoders which are rather thin on the ground.

 

Thanks for that, Suzie. As I'm using a separate power source though, isn't the power output of the Switchpilot irrelevant? If the power to move the points is coming from an external power source, all the Switchpilot has to do is trigger the movement, isn't it? But, having said that, I'm not getting the kick on the points that I would expect of 12-24V DC, which is my problem.

[Waverley West]

As part of my recent point motor experiments, I bought a Cobalt digital point motor and spent half an hour last night installing it. I have to say, I was very impressed. Installation was simple and setup was even easier. I've been wanting slow action motors for some time now and this might actually be the route to go for me. Connecting up the frog wire couldn't have been any easier too and after my frustrations over the past couple of weeks with ZTCs, Switchpilots and solenoids it was a breath of fresh air to install a digital point motor so easily. Unless I can get my ZTC 304s all working properly, I would have to replace them anyway, and switching to, say, Switchpilots plus low current solenoids wouldn't be significantly cheaper than going down the all-Cobalt digital route. And I'd get slow action motors too.

 

Food for thought methinks.

 

Cheers

Dave

[Phil S]

NO - The SwitchPilot's Power Output (CAPABILITY) IS Extremely important ..... if you chase back along your power provision, you have the entire national grid 'available', but not usable!

The SwitchPilot is the device turning on and off the Power Stage inside the SwitchPilot for that particular direction/output ....  It is designed for a certain capacity, above which it may either restrict further current flow, or fail!.  ESU have provided an option to allow higher currents for a SHORT period (to cope with A Peco Motor) - because it is the heat buld up during current flow that causes the potentially damaging effects.  Repeated operation, in a short time period in this Peco mode is probably not advisable.

In a similar vein, much domestic equipement - from electric tin openers and carving knives, to portable drills are rated for a maximum of say 10 minutes continuous use, with a similar break to allow cooling.

 

I'm not sure of the internal circuitry, of the ESU - whether it is simply switching the incoming external power through to the outputs, unchanged, or it is rectified ..... I suspect the FORMER, in which case there WILL probably be a considerable difference between 'DC' and 'AC' external power supply provision in operating the coils - ALSO 'DCC' is available...  [Obviously, it also rectifies the incoming power, and regulates it to 5V for the internal control logic, but that is a separate process to the output stages]

 

When I tested using the different power sources: DCC, DC and AC, I observed different capabiliites when I tested it on a Roco Uncoupler (Solenoid)

Remember that when referring to '16Vac' it is the RMS voltage being quoted - and the the PEAK value will be 1.4 x that, if all else was equal - but it probably isn't.....

THE AC supply will probably be coming form an unregulated TRANSFORMER OUTPUT .... and when 'little/no current' is taken, the voltage will be considerably higher ... maybe 20V RMS 28V peak

This, if passed straight through to the solenoid will give a hefty initial kick, as the voltage then falls with the current being taken.

 

ALSO with AC, the IMPEDANCE of the coils will be HIGHER than the plain RESISTANCE measured at (and preceived by) the DC supply .... and this AC or CDU discharge is what they are designed for.

The DC voltage, if switched through directly, will only have the quoted peak/steady value and the DCC voltage would typically be only 16V or less.

 

It is also a 'waste of resources' to use a regulated DC supply for a device designed for a short term ac burst, which doesn't require precision regulation.

[Suzie]

If you are thinking of changing the solenoids for something else it is worth considering servos. ESU make the Switchpilot Servo with the Switchpilot Extension for frog switching, or alternatively there is the Signalist SC2 which is an integrated unit which has frog wiring just as easy as the Cobalt but with a more flexible power supply option.

[Waverley West]

NO - The SwitchPilot's Power Output (CAPABILITY) IS Extremely important ..... if you chase back along your power provision, you have the entire national grid 'available', but not usable!

The SwitchPilot is the device turning on and off the Power Stage inside the SwitchPilot for that particular direction/output ....  It is designed for a certain capacity, above which it may either restrict further current flow, or fail!.  ESU have provided an option to allow higher currents for a SHORT period (to cope with A Peco Motor) - because it is the heat buld up during current flow that causes the potentially damaging effects.  Repeated operation, in a short time period in this Peco mode is probably not advisable.

In a similar vein, much domestic equipement - from electric tin openers and carving knives, to portable drills are rated for a maximum of say 10 minutes continuous use, with a similar break to allow cooling.

 

I'm not sure of the internal circuitry, of the ESU - whether it is simply switching the incoming external power through to the outputs, unchanged, or it is rectified ..... I suspect the FORMER, in which case there WILL probably be a considerable difference between 'DC' and 'AC' external power supply provision in operating the coils - ALSO 'DCC' is available...  [Obviously, it also rectifies the incoming power, and regulates it to 5V for the internal control logic, but that is a separate process to the output stages]

 

When I tested using the different power sources: DCC, DC and AC, I observed different capabiliites when I tested it on a Roco Uncoupler (Solenoid)

Remember that when referring to '16Vac' it is the RMS voltage being quoted - and the the PEAK value will be 1.4 x that, if all else was equal - but it probably isn't.....

THE AC supply will probably be coming form an unregulated TRANSFORMER OUTPUT .... and when 'little/no current' is taken, the voltage will be considerably higher ... maybe 20V RMS 28V peak

This, if passed straight through to the solenoid will give a hefty initial kick, as the voltage then falls with the current being taken.

 

ALSO with AC, the IMPEDANCE of the coils will be HIGHER than the plain RESISTANCE measured at (and preceived by) the DC supply .... and this AC or CDU discharge is what they are designed for.

The DC voltage, if switched through directly, will only have the quoted peak/steady value and the DCC voltage would typically be only 16V or less.

 

It is also a 'waste of resources' to use a regulated DC supply for a device designed for a short term ac burst, which doesn't require precision regulation.

 

Thanks Phil, very informative. That certainly ties in with my observations and explains my problem. I assumed that because I was using an external power supply there was plenty of oomph getting through to the PECO motors, but clearly not in the case of the Switchpilot. Changes are obviously needed then.

[Waverley West]

If you are thinking of changing the solenoids for something else it is worth considering servos. ESU make the Switchpilot Servo with the Switchpilot Extension for frog switching, or alternatively there is the Signalist SC2 which is an integrated unit which has frog wiring just as easy as the Cobalt but with a more flexible power supply option.

 

Thanks Suzie. Yes, I'm definitely considering changing the solenoids. As much as anything, I'd like slow action motors. I'm very tempted by the Cobalts but will look into the servos too.

[two tone green]

Output of the SwitchPilot is DC although the input can be either AC or DC

 

If you can input DC all the better as you don't waste any of the available power in converting AC to DC and end up just warming up the layout.

 

Did you make sure the Switch Pilot has its configuration switch on the unit is in the middle.. Its marked DCC I think rather the either of the two K modes which are useful for signals etc.

 

Not at home at the moment to check and on a slow internet connection in a field

[Waverley West]

Output of the SwitchPilot is DC although the input can be either AC or DC

 

If you can input DC all the better as you don't waste any of the available power in converting AC to DC and end up just warming up the layout.

 

Did you make sure the Switch Pilot has its configuration switch on the unit is in the middle.. Its marked DCC I think rather the either of the two K modes which are useful for signals etc.

 

Not at home at the moment to check and on a slow internet connection in a field

 

Yep, configuration switch is in the middle. Wiring up the signals again is the next challenge after the points of course... 

[TWG]

As Suzie has pointed out, the Switch Pilot has a normal output maximum of 1.5A, so it is at its absolute limit when switching one point.  This means that even if you could get it to switch two it would be unwise to do so.

 

I see two simple and cheap solutions.  Replace the Peco motors with the green version.  Since you say that the single motors work all right, you will have to buy only 2 motors, you can leave the rest as they are.  The alternative is to use a relay with adequate current carrying capacity.  The SP switches the relay, the relay switches the points.  That way you can incorporate a capacitor discharge unit if required.

 

I suggest that you put the mode switch in the k83 position.  This means that all outputs are pulses (k83 and k84 are Märklin's designations for different types of accessory decoder).  If you have the switch in the middle position you can use CVs 3 to 6 to set the outputs individually, but you want them all the same.

[two tone green]

Once home I can play and help a little better than where I am at the moment.

 

Don't give up. there is an answer out there to these issues. I sued the Switchpoilt of years on my large complex OO layout with great success using Peco point motors. The older black ones did work but did find better reliability from the new green ones and eventually change 96 motors over to them and never looked back.

 

now in O gauge I use my SwitchPilots with non digital DCC Concept Cobalt's with good success as well.

[GoingUnderground]

I use cheap model aircraft micro servos with SwitchPilot Servo, and they work well. You have to rig up a switch separately for frog polarity though.

 

I have read on another forum that there can be problems with Cobalt digitals as many DCC systems tend to run at a higher output voltage than the Cobalt digital can handle comfortably. At least one US retailers of Cobalts is now including a 250 Ohm resistor to go in line to supply to the Cobalt digital to drop the voltage, see attached image.

[Combe Martin]

I have no experience of an ECoS or Switchpilots, but I see no mention of using a CDU here at all.

 

I'm a ZTC user and my double track layout has a single wiring bus feeding it, and with my 304s all connected directly to the bus and with no external power supply.  But each 304 has it's own CDU wired in too.  There are several crossovers using old style (second hand too) Peco solenoids wired to the 304s in parallel (not in series), and in each case both solenoids switch perfectly every time.  As is recommended in this case, I've got my 511 set to output a slightly higher voltage to the bus (15 or 16 volts ?, I can't remember at the moment, and I'm not at home to check) but I'm having no problems.

 

Ok, I'm not using Switchpilots, but you mention having problems even with some 304s, but I don't, so I wonder what the difference is (apart from a CDU ?) ?

 

Are some of your Peco solenoids/point combinations a bit more sticky than others ?, which you'r now discovering when moving to an accessory decoder with a lower output ?

 

I have found that the position of the Peco solenoid can be quite critical, and with some, if it's not central to the point both across and in line, and exactly 'in line' with the point tie bar, then the whole combination can be a bit too stiff, even for fingers !    

[GoingUnderground]

You cannot use a CDU directly with SwitchPilot. If you do want to use a CDU then you will have to arrange for each output of the SwitchPilot to operate a SPST relay and each relay in turn will switch the supply from the CDU to the solenoid. So for one solenoid you would need 2 SPST non-latching relays.

 

EDIT: Here is a simplified wiring diagram of how to do it.

You keep the SP on pulse setting, and you can use either an independent power supply or the DCC for the SP. The SPST (Single Pole Single Throw) relays would probably need to be 24V non-polarised ones, thought you might be able to get away woth 12V ones, it depends on how you power the SwitchPilot. The relay isolates the SwitchPilot from the CDU.

 

You operate the point on your DCC controller, that sends he signal to the SP, it momentarily completed either the A or B circuit. That operates Relay A or B as appropriate. Whilst the relay is energised from the SP, it completes the circuit from the CDU to the solenoid and throws the point.

[Crosland]

If you can input DC all the better as you don't waste any of the available power in converting AC to DC and end up just warming up the layout.

 

The input goes through the same pins! DC input will still flow through the rectifier and cause just as much warming.

 

The situation is worse as the DC will flow through only two of the diodes in a bridge rectifier instead of two for 50% of the time and the other two for the other 50% of the time with AC. All of the power "wasted" is concentrated in two diodes instead of 4.

 

Andrew

[Phil S]

As Andrew commented: re DC v AC power input to the Switchpilot

The input goes through the same pins! DC input will still flow through the rectifier and cause just as much warming.

 

The situation is worse as the DC will flow through only two of the diodes in a bridge rectifier instead of two for 50% of the time and the other two for the other 50% of the time with AC. All of the power "wasted" is concentrated in two diodes instead of 4.

 

Andrew

 

Phil: IN ADDITION, IF the incoming DC was 'smooth' or regulated - as, for instance from an nice Switched mode power supply 8-) - then, for 'equivalemt' voltages, the AC input will have a 1.4x higher PEAK voltage .... and if there are capacitors inside the SwitchPilot, after the Power-Input-Bridge-Rectifier, then the DC voltage available INTERNALLY (and therefore the uumph! available for a brief switched pulse - will be perhaps 1.4x or even 1.4 x 1.4 x that of the DC supply with the same notional voltage ( with the capacitor charged to the peak voltage).

[The comparison is unlikely to be perfect though, as the ac supply is likely to be unregulated, and therefore much higher than the indicated value which applies when the full current is being taken .... err  that might mean even more uumph with ac ]