power problems with peco switch machines

[nfmisso]

QUOTE: Originally posted by der5997

My 25 volt capacitor unit .....

But what is the capacitance of the capacitor ????

[der5997]

QUOTE: Originally posted by Don Gibson

DER 5997

the voltage rating is there so as not to exceed - in short the 25volts is nominal for a 12 volt source - and were talking DC here - It;s the CAPACITANCE (mfd) that does the work.
1. it could have lost it's 'storage' ability.
2. It was too small in the first place to handle 4 switches... But two??
3. The 'Charging' source isn't charging it.
4. The rewiring could have created something.
5. The slugs in the coils are rusted.

First run a test bypassing the new wire. No change? replace the Capacitor.

Thanks Don: I knew that someone with the right answers would happen along.
Of your diagnostics, #5 appeals to me most as these PL10s had been in attic stroage for at least 5 years prior to rescue and re-use.
I'm pretty sure the unit is charging, since it works the single turnout motors with more zip than an ordinary power pack. (subjective observation)
I was wondering if the simuteaneous pushing of the buttons might have something to do with the failure to perform. I'm not sure now, but I thnk that on the crossover I had on the last layout the two pairs of PL10s may have been operated from just two Atlas turnout controls (in other words 2 motors were wired to the same control.
Regards

[grayfox1119]

In an inductive load, Voltage leads the Current

[Don Gibson]

DER 5997

the voltage rating is there so as not to exceed - in short the 25volts is nominal for a 12 volt source - and were talking DC here - It;s the CAPACITANCE (mfd) that does the work.
1. it could have lost it's 'storage' ability.
2. It was too small in the first place to handle 4 switches... But two??
3. The 'Charging' source isn't charging it.
4. The rewiring could have created something.
5. The slugs in the coils are rusted.

First run a test bypassing the new wire. No change? replace the Capacitor.

[der5997]

QUOTE: Originally posted by Fergmiester

Now that we're talking switch machines I have two questions
a) Can you drive 4 peco switch machines at once with a single capacitor?
b) could this be unsafe with all the high voltage?

Regards
Fergie

Fergie: My 25 volt capacitor unit won't. I tried it by simultaneously pressing 4 Atlas switch machine buttons. No turnouts fired. Each fired individually before this test.
Large portions of egg on my face howeverin the light of what I wrote to retsignalmtr, because I couldn't get 2 to fire simutaneously either.[B)](or [dinner]depending on whether you like eggs!)
Not an opperating issue for me, as I don't need to be able to fie 2 at once, but it's got me wondering. This unit used to be able to fire 2 at once. I'm using lighter wire (it was free, and I canna abide waste!) than I used on the previous layout. Maybe that's the problem.

As to danger, I think that if the motors are not firing, there is no danger. It's a very brief current pulse. The voltage would remain the same regardless of the number of motors connected, there would be less amperage going to each motor coil, and that's why they don't fire. At least that's how I see it. Maybe Nigel has a correct explanation if I'm wrong.

Do you get to see the forum while at sea?
Regards

[Don Gibson]

Simple answer

Most Selenoid or 'twin coil' switch machines need 3 amps apiece (peak) to throw your switch. That's one of the reasons you want only momentary contact, so not to burn out coil wires. Most DC power packs have 2 - 3 amps.

That's fine for one turnout - or exhausting for two at the same time.

A large Capacitor stores enough current for multi turnout simultaneous throws - exhausts itself, and prevents coil burnout at the same time. Works with momentary push-buttons, or toggles with less arcing. Marvelous with a diode matrix board for track routing through a yard throat.

EDIT: answer three questions:

High Voltage? No. The capacitor stores Amps. think of it like a car battery. A car battery puts out 12 volts but enough amps to weld a steel rod.
Heavy guage wire? I don't think so. The pulse duration is too short to cause heat. Extra long length's (100' have voltage drops- take for example nickle silver rail -and look how thick it is.
How many turnouts can be thrown simultaneously? just add them up 3 amps per, and increase the size of the capacitor. I use 10,000mfds which may be club size, but I have never exceeded it's capacity... and no, I have never damaged a turnout.

[BR60103]

Nigel: I've never had to control 2 at the same time that were 8 feet apart. Most I get is two feet.
I do have peco machines from 3 different eras -- back to the plastic frames from 1970. I know that trying to pair them with other brands leads to problems where one machine sinks all the power.
Fergie: You should be able to do 4 at once, if your capacitor is big enough. And for some reason, it doesn't affect things if you only do 1 at a time.

[retsignalmtr]

thanks for all your help guys. the mrc powerpacks seemed not to have enough power to operate more than one peco switch machine at a time. so we switched to a starrtech hogger and the problem was solved.

[Fergmiester]

Now that we're talking switch machines I have two questions
a) Can you drive 4 peco switch machines at once with a single capacitor?
b) could this be unsafe with all the high voltage?

Regards
Fergie

[nfmisso]

QUOTE: Originally posted by BR60103

Two other points:
I try to have the same length of wire going to both switch machines.

Why? So say you have one machine ten feet away, and another two feet away - what do you do with extra eight feet of wire?

QUOTE:
I try to have them come from the same batch (or at least, bought from the LHS at the same time) as they have varied the design at times. I think they also have a couple of different machines now.

For twin coil machines, use as large guage wire, and keep it as short as possible - too minimize voltage drop with the high in rush current.

[BR60103]

Two other points:
I try to have the same length of wire going to both switch machines.
I try to have them come from the same batch (or at least, bought from the LHS at the same time) as they have varied the design at times. I think they also have a couple of different machines now.

[nfmisso]

QUOTE: Originally posted by retsignalmtr

my question is can the accessory windings on two powerpacks be connected in parallel to get a little more power to the switch machines without damaging the powerpacks?

Definitly not recommended.

As said above, a capacitive discharge supply is the way to go. Even a basic trainset pack has plenty of power to charge the capacitor.

[der5997]

QUOTE: Originally posted by Fergmiester

I can switch two turnouts at once with a home made unit. This includes peco slide switches. The ability is subject to the capacitor in use. Maritime Hobbies of Halifax, NS sells a unit that can do this. Ask for Mike and tell him Fergie sent you.

Another option is to contact nfmisso on the Forum as he is handy when it comes to electronics.

regards
Fergie

Hey Fergie: Wind's died down a bit up the shore. Looks good for you Thursday!
Peter Thorne has this to say about the 2 turnouts ata time thing (and these are home made units BTW)
Operating: Connect the CD unit between the a.c. terminals of the power pack and the controls for the switch machines. As with the (simple) unit, you can operate two switch machines simultaneously with this (quick recovery) unit.
Points to Watch: Don't use more than 16 volts for the input. Even going to 18 volts requires a 35 or 50 volt capacitor. Don't skimp on the wire gauge to the controls and the switch machines. If anything, you need heavier wire than with conventional controls because the C.D. unit supplies a heavier current for a shorter time.
He also cautions that turnouts with built in lamps will suffer blown lamps.
I've not had problems with the wire gauge issue, and am very satified with the way the units snap the machines, especially the Peco PL10s.

[Fergmiester]

I can switch two turnouts at once with a home made unit. This includes peco slide switches. The ability is subject to the capacitor in use. Maritime Hobbies of Halifax, NS sells a unit that can do this. Ask for Mike and tell him Fergie sent you.

Another option is to contact nfmisso on the Forum as he is handy when it comes to electronics.

regards
Fergie

[der5997]

QUOTE: Originally posted by retsignalmtr

my club has replaced the switches on their traveling layout and we are having some problems with some of the peco switch machines where more than one machine must operate at the same time. we are using mrc tech II powerpacks and it seems there is not enough power to operate them together. my question is can the accessory windings on two powerpacks be connected in parallel to get a little more power to the switch machines without damaging the powerpacks?

No need to go to those lengths (that would probably invalidate any remaining waranties anyway [V]

What I would suggest is a capacitor discharge unit to power your turnouts. A simple one is very easily constructed, and a quick recharge one, that may suit your needs better, is not that much more complicated. One unit, run off a spare power pack, will simultaneously power several PL10s.
Details of these units are to be found in Peter Thorne's Practical Electronics Projects for Model Railroaders Chapter 5, Switch Machine Controls.
Hope this helps.

[retsignalmtr]

my club has replaced the switches on their traveling layout and we are having some problems with some of the peco switch machines where more than one machine must operate at the same time. we are using mrc tech II powerpacks and it seems there is not enough power to operate them together. my question is can the accessory windings on two powerpacks be connected in parallel to get a little more power to the switch machines without damaging the powerpacks?