does a trannie "regulate" house current

Walt,

In general no.  Transformers do not regulate.

-Bill

No...the transformers you list do not provide any voltage or current regulation.

RATS!  Anyone want to buy an unused 4804

I'm really surprised that he didn't design it in.

I'm curious now that I just thought of it: Is there a device that lands up acting like a "regulator"?  Sorry about my most crude word usage, but not being too electrically in tune I can only use words that I can relate to.

thanks - walt

walt rapp posted:

I have had issues in the past using an unregulated wall-wort to power Miller's signs, destroying 3 before Chris suggested not using his original unregulated power source and buying a regulated one.  I did and haven't had an issue since.

I recently bought his 4804 converter.  It is designed to be connected to a transformer (ZW, Z4000, MRC 270, etc) and then to the signs.  Just this week it struck me to ask Chris if it is 'regulated' or not.  I thought for sure that after his first wall-wort was created unregulated and he subsequently scrapped it and designed a new regulated one that he would ensure that this new 4804 is regulated.  I asked him yesterday and he wrote back saying:

Hi Walt,

 Sorry for the late reply.  How are you? The 4804 you are referring to is not regulated. It uses what ever is fed into it, so if the input is not regulated then neither will the output.

Thanks,
Chris

 

So my question to you guys is this:  since my wall current must run thru my transformer first (choices are PW ZW, a PW V, or an MRC dual 270) will the transformer land up "regulating" things???? 

 

As always, thanks - walt

As others have said the transformer will not regulate. BUT, the 4804 is a regulated power supply that simply takes an unregulated input from the transformer, 5 to 17 vac as the website says, and puts out a 4.5 vdc for the signs. I don't understand Chris' reply to you.

As for the 4804 that he sells, it will produce a bit of heat regulating 17 vac down to 4.5 vdc, if you use it I would reduce the transformer output to something like 6 or 7 vac.

As an alternative, I use a transformer to power "switching" regulating supplies. They are available on ebay, etc. and do not produce the heat of a linear regulator such as the 4804. Lots of info here...

https://ogrforum.com/t...23#56756833218099423

Thanks Chuck.  I'll ask Chris again and see how he replies.  I sure as heck hope you are right!!!!!

Curious: how do you know that it outputs a regulated flow?  I'm not challenging you mind you, just asking.  If appropriate and with your permission I would like to mention to Chris what you say, if appropriate.

thanks - walt

Here is the data from Miller signs website: 

"Accepts an input voltage from 5 to 17 volts, AC or DC."

#4804 - Converter module. This unit
will replace your battery pack. It will let
you run your signs off track voltage or
your power pack. Accepts an input
voltage from 5 to 17 volts, AC or DC
and outputs the required 4.5 volts for
our signs. Will run up to 6 signs.

AC power by it's very nature of being cycled between the positive and neutral poles to provide the inertia to move the power over longer distances than DC has never been very accurate in terms of voltage.  120 volts AC can be roughly anywhere between 110 and 130 volts. 

Transformers that not only drop voltage but convert AC to DC power have a rectifier that is a solid state device that takes the varying voltage of AC and creates a constant DC voltage.  At least that is how it's supposed to work. 

Thanks guys!

I thought the same thing: if it can accept different input and output a constant 4.5V, doesn't that mean it clamps down to a consistent output.

I'm going to ask Chris a again and see what he says.

thanks again - walt

walt rapp posted:

Thanks guys!

I thought the same thing: if it can accept different input and output a constant 4.5V, doesn't that mean it clamps down to a consistent output.

I'm going to ask Chris a again and see what he says.

thanks again - walt

Yes, that's what it means. It takes anywhere from 5 to 17 vac and is regulated to put out 4.5 vdc. I don't know if maybe Chris was missing your question. The regulation to 4.5 vdc has a limit of a certain number of signs. Each sign draws about 0.08 amps. So if the regulated supply is meant to run 6 signs, then the supply output is up to about a half amp or so.

AND I'm wrong about the heat issue. Now that I look at the picture of the regulator, it looks like a "switching" supply judging by the little chip I can't identify and the little toroid coil. So it should run quite cool. Sorry for my assumption that it was a linear supply, but the one I bought a few years ago from them was and got quite hot.

This board should be great for your signs.

Thanks Chris for the positive feedback.  I will be emailing Chris in a minute or 2 and I'll come back here to report what he says.

as always - thanks, walt

Be careful with over-voltage on those.  I'm a bit surprised that they didn't make the input voltage range wider, given the range of transformer voltages used with model trains.  With a buck-mode switching power supply, it is trivial to have a wider voltage range.

John,

Thanks for jumping in!  I don't understand your comments, being electrically challenged and all.  I have an email into Chris asking but haven't heard back yet.

I'm thinking that I might want to use a dedicated trannie (one from a old starter set) because I don't know enough to know that if I have a derailment on a track powered output that it doesn't in any way affect the other output posts on that trannie.

thanks again John - walt

Well, with a 17VAC max, I'd be using a small accessory transformer at around 12VAC to power this adapter.

Chris got back to me after I re-asked my question, mentioning some of the things that were brought up here.  Below is his reply this morning to me.  It sounds like he's saying Don't Use It.  One other way I thought about his comments is that possibly he was vague and non-committal so that in the event that I used it and one of his signs gets ruined I wouldn't be able to go back to him and say "You said it was safe".  Not that I feel that Chris is that kind of person but it was one of my first thoughts.

I think I'd use a 5V regulated wall-wart and toss a diode in to drop the voltage to around 4.5V.  That's what I do for my Lemax buildings, it works great.

WOW, Chris got back to me a 2nd time after I responded to his email by saying I guess I just won't use it.  Here's his positive message:

John,

I have a regulated one that is good for up to 10 signs.  I've used it ever since 8 years ago Chris suggested that I buy a regulated power source.  I saw this new product and liked it since it's Transformer powered (more convenient) so I bought it. 

Also, I am in no way electronically smart enough to even try to build something.

- walt