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SLow energy Peco point motors

ColinB

1305 posts

Thanks Chrissaf for the data, I am not an expert on solenoids, I need to go and do some reading. I think they assumed by doubling the number of turns on the coil they would get the the same effect. The thing is if you load it up with one of their slider switches that fit under the motor it would never work, even with a PL10 there are issues, that is why I use microswitches. The thing I cannot get my head around surely they did the same tests you did before marketting it.

Buz

1532 posts

Hi Guys

First up never destroyed a point with a twin-coil solenoid yet be it an old Hornby Type or Peco type.

18v seems a little high I use nominally 16V with a CDU to operate mine which seems to be the normal recommended accessory feed and extra for analogue which I use there are exceptions I know.

I would have thought that the DCC Witchcraft had its own recommended style of point motor it seems to have its own everything else that is different and three times more expensive to set up, and no one seems to get  it even with the spell book to make it work.

I really don't think the power consumption from our toys makes a lot of difference in the overall scheme of thiing's

As far as I know PL10's are still available if not it will be a lurgy Hiccup

I am wondering what the new red ones are like I haven't seen anything on them yet.

regards John

Chrissaf

11838 posts


Community Moderator

18v seems a little high I use nominally 16V with a CDU to operate mine which seems to be the normal recommended accessory feed and extra for analogue which I use there are exceptions I know.

 

I assume you mean 16 volts AC. If so, that equates to a DC voltage higher than 18 volts DC.

 

All sinusoidal AC voltages are stated by normal convention as RMS values.

 

Based upon "Physics O Level" science. The PEAK AC voltage of a 16 volt AC RMS voltage is 16 x 1.414 = 22.6 volts. [1.414 is the RMS to PEAK conversion factor].

 

Once this 22.6 volt 'PEAK' AC voltage is full wave rectified you get an equivalent DC voltage of 21.4 volts [bridge rectifier drops 1.2 volts] if large smoothing capacitors are used OR a voltage nearer 19 to 20 volts if not smoothed. Either way, these are higher than 18 volts DC. Remember that a CDU outputs a DC voltage thus the input AC voltage is rectified within the CDU [typically, but not always, by half way rectification and not full wave which delivers even more power].

 

PS

PL-10s are still readily available, the question was about the PL-10W and PL10-WE which are different PECO products. PL-10s have 'Black' coils. The PL-10W variants have 'Green' coils to denote their 'Low Energy' green credentials.

 

Chris........ Making the wood in the trees visible.

ColinB

1305 posts

I think is is 18 volts as it comes off a 15 volt transformer, but I cannot guarantee that, it should be 21 volts, according to your formula, originally all the points ran off the raw 15 volts. I built the controller about 30+ years ago, I will measure it next time. It uses 15 volts as the op amps that I used for the rest of the circuits run on +- 15 volts, we are talking 1980's technology. I did some surfing and checked in my electrical engineering books and it should work, but obviously it doesn't. In all the formulee I found it appears it revolves round (Number of turns * current)  all squared, so if you double the number of turns you halve the current, so it should be same. As I said I am no expert, definitely not on AC and inductors, so I am obviously missing something, but there again so did Peco. Either way it doesn't matter, practically they don't work. I intend using a 16 channel accessory module that uses 5 volt switching, so I have got to use relays anyway, plus it gives me the option of digital and analogue control, so I will just use them where I am not loading them up with microswitches.

Chrissaf

11838 posts


Community Moderator

In bandying about all these voltages ... 15 volts this ... 18 volts that ... it is essential to state whether these voltages are AC or DC.

 

AC and DC voltages are not the same in the way that they are used in electrical calculations. And therefore their numerical values can not be interchanged as representing the same measurement of voltage. As I said in my last reply, sinusoidal AC voltages are stated as RMS values. You have to understand what RMS means. It is a mathematical way of expressing equivalent power in an AC waveform.

 

Then there is 'off load' and 'on load' stated voltages. Most AC transformer voltages are stated 'on load' at their rated current load. So a 15 volt AC transformer will easily measure 18 to 21 volts AC when 'off load', but it is still labelled as a 15 volt AC transformer.

 

.....it should be 21 volts, according to your formula.

 

Not correct.

 

The 21 volt figure was quoting the DC Voltage after DC rectification, whereas the 16 volt figure was an AC RMS value ..... something completely different.

 

A 16 volt AC RMS voltage is a 'PEAK' AC voltage of 22.6 volts, but any normal AC multimeter is calibrated to read the RMS value ... in this case 16 volts AC.

 

This is the very 'Ping Pong' 'To and Fro' 'Going round in Circles' dialogue I was trying to avoid by not commenting on the original question earlier. And I now wish I hadn't bothered.

Chris........ Making the wood in the trees visible.

ColinB

1305 posts

It is very nice you explaining it to me and I may be a bit flippant about voltages, but I know exactly what you mean, the information about the tests on solenoids filled in the gaps. I did power and machines for three years, it was part of my 4 year electronics degree. So yes I know exactly what RMS is, I know about ripple and maximum values, I also know all about power supplies, I used to design them. It is just I didn't want to say anything, especially after last time's telling off. I know very little about inductors and solenoids because basically they don't really follow ohms law and I have never really used them, same with triacs and scrs, other than for crowbar protection in power supplies. The only thing I do know about solenoids and inductors is to put a reverse diode across them to stop the back emf killing the driver. Normally I would go and ask a colleague at work, but I retired. So yes I know the difference between AC, DC, half wave rectified AC etc, I may be a bit rusty but when it comes to the crunch I know what they are and I still have a ton of books on it. As for the 18 volts I need to check my power supply, as I said I initially designed the box as a 4 track pwm controller, it has been modified extensively over the years plus I have bought in cdu, so I have not analysed what voltage it runs at.  I think the cdu required 15 volts AC as an input so that is exactly what it got as for its output, I must at some time measured it and got 18 volts, but for all I know it could have been the multimeter reading some transient. If it was important, I would measure it properly.

RAF96

13580 posts


Community Moderator

OK - that is great theory, which I fully understand, but in practice this is what I have seen in recent testing.

 

The new HM6010 DC Point and Accessory Module (PAC) module is the R8247 Point and Accessory Decoder (PAD) of the DC world, except it has themsame number of capacitors but they are half the value of the DCC module and we know the R8247 is no muscle mechanic when it comes to throwing solenoids, especially in pairs.

 

The basic HM6010 module design is almost the same as the R8247 apart from the HM6010 having blue tooth connectivity to the operating app rather than being hard wired to a controller and it also has a high amp output on one port to be able to drive a turntable motor.

 

The PAC unusually has two alternative modes of power - 15vDC i.e the same as Select and Elite or eLink or direct DCC track voltage as output by any of those DCC controllers. One would think the internal circuitry of the PAC would produce the same potential at the port outputs, but ...

 

... throwing points - on straight DC voltage the HM6010 is not that reliable, especially throwing paired solenoids, but power it from a DCC track voltage and there is a noticeable increase in throw potential. You can actually hear the difference in click between the two powering arrangements on this module, which is factory set at the default 100mS pulse. Work goes on to try various pulse durations on the HM6010 as is currently possible to set on the R8247 via CVs.

 

Given that the CDU output of these modules is governed by the capacitor value and quantity then one would expect the R8247 PAD to out perform the HM6010 PAC by a wide margin.

 

Now if we look at the new basic DC controller R7227, which has the same value capacitors as the PAC but only two rather than four, yet it will reliably throw a pair of solenoids on a standard 15vDC power input.

 

Open to further discussion.

 

Halton Brat - Running Win 10, 64-bit - RM (Pro-Pack) with Elite as Controller-A, Select as Walkabout and E-Link as Controller-B - Locos are mostly TTS. http://www.halton96th.org.uk/robs_rails.html

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