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Subject: 
Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Fri, 17 May 2002 12:33:47 GMT
Viewed: 
1151 times
  
I find batteries a pain, especially as there output isn't constant over
their lifetime, therefore I'd love to be able to power my motors from the
mains. I'd like to know what methods their are are doing this. I'd prefer a
purist option but I do know which end is the dangrous one on a soldering
iron. It also has to work in the UK, home of the three pin plug.

Ta

Steve


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Fri, 17 May 2002 12:53:41 GMT
Viewed: 
1211 times
  
In lugnet.technic, Steven Lane writes:
I find batteries a pain, especially as there output isn't constant over
their lifetime, therefore I'd love to be able to power my motors from the
mains. I'd like to know what methods their are are doing this. I'd prefer a
purist option but I do know which end is the dangrous one on a soldering
iron. It also has to work in the UK, home of the three pin plug.

Purist approach is to use a 9V train speed reg and LEGO(r) wires from the
speed reg to your motor(s), possibly through the polarity reverser switch to
give control. The speed reg is powered from a wall wart trafo so if you buy
a UK train set or UK used speed reg (should not be too hard to come by) or
even pay LD's high price for a new one, you should be all set. The UK wall
wart will have the appropriate 3 pins for your funky mains points and will
be 220v compatible.

The wall wart from a speed reg can also power an RCX that has the power
connector (1.0 but not 1.5. I do not know if they put it back for 2.0 or
not) if you want to go that way...

Hope that helps.


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Fri, 17 May 2002 13:39:08 GMT
Viewed: 
1198 times
  
In lugnet.technic, Larry Pieniazek writes:
In lugnet.technic, Steven Lane writes:
I find batteries a pain, especially as there output isn't constant over
their lifetime, therefore I'd love to be able to power my motors from the
mains. I'd like to know what methods their are are doing this. I'd prefer a
purist option but I do know which end is the dangrous one on a soldering
iron. It also has to work in the UK, home of the three pin plug.

Purist approach is to use a 9V train speed reg and LEGO(r) wires from the
speed reg to your motor(s), possibly through the polarity reverser switch to
give control. The speed reg is powered from a wall wart trafo so if you buy
a UK train set or UK used speed reg (should not be too hard to come by) or
even pay LD's high price for a new one, you should be all set. The UK wall
wart will have the appropriate 3 pins for your funky mains points and will
be 220v compatible.

The wall wart from a speed reg can also power an RCX that has the power
connector (1.0 but not 1.5. I do not know if they put it back for 2.0 or
not) if you want to go that way...

4548s were 5ukp in Toysrus a while back

Someone in the UK has a UK 3 pin adaptor for $5

http://www.bricklink.com/store.asp?p=phillwright&itemID=504739

I'm sure you can find a UK person to trade a controller.

Mark


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Fri, 17 May 2002 13:43:18 GMT
Viewed: 
1100 times
  
In lugnet.technic, Larry Pieniazek writes:
In lugnet.technic, Steven Lane writes:
I find batteries a pain, especially as there output isn't constant over
their lifetime, therefore I'd love to be able to power my motors from the
mains. I'd like to know what methods their are are doing this. I'd prefer a
purist option but I do know which end is the dangrous one on a soldering
iron. It also has to work in the UK, home of the three pin plug.

Purist approach is to use a 9V train speed reg and LEGO(r) wires from the
speed reg to your motor(s), possibly through the polarity reverser switch to
give control. The speed reg is powered from a wall wart trafo so if you buy
a UK train set or UK used speed reg (should not be too hard to come by) or
even pay LD's high price for a new one, you should be all set. The UK wall
wart will have the appropriate 3 pins for your funky mains points and will
be 220v compatible.

The wall wart from a speed reg can also power an RCX that has the power
connector (1.0 but not 1.5. I do not know if they put it back for 2.0 or
not) if you want to go that way...

Hope that helps.

Thanks Larry and JB (via e-mail)

I'll be following your advice. I'd always assumed the track power connection
was hard-wired but this pic shows where a standard connecter attaches.

http://guide.lugnet.com/set/?q=4548_1&v=z

And the speed regulator facility might come in handy too.

Steve


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Fri, 17 May 2002 14:54:48 GMT
Viewed: 
1225 times
  
In lugnet.technic, Mark Morgan writes:>
Someone in the UK has a UK 3 pin adaptor for $5

http://www.bricklink.com/store.asp?p=phillwright&itemID=504739

That particular lot would be exactly what to buy if you had an RCX 1.0 you
wanted to power, it is exactly what you need and no extra.

Those 4548s turn up in the strangest places, though, so haunting old and
poorly managed stores (TRU comes to mind, as Mark said!) that carried the
4558 at one time in the past might be an excellent approach to picking up
the trafo and the speedreg. Good luck!


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Sat, 18 May 2002 01:41:22 GMT
Viewed: 
1265 times
  
In lugnet.technic, Larry Pieniazek writes:

The wall wart from a speed reg can also power an RCX that has the power
connector

You can do this but it's not recommended. As the RCX 1.0 has a bridge
rectifier on the power input, it's recommended you use a 10v AC supply, to
avoid buring out the diodes.

ROSCO


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Sat, 18 May 2002 03:31:01 GMT
Viewed: 
1469 times
  
I think you misuderstood what Larry said (or I misunderstood what you
said). I think Larry was saying that you should use the wall wart from
the train speed regulator, which is what Lego recommends. Also, I dont
see how you could burn out the diodes in the rectifier.* All the
discrete diodes in the RCX are 1N4002s, which can transmit at least 1
amp. However thay could have used a monolithic rectifier, but I dont
think Lego would produce anything that would fail like that.

*If youve done it, and youre sure thats what happened, then I stand
corrected.

Ross Crawford wrote:

In lugnet.technic, Larry Pieniazek writes:

The wall wart from a speed reg can also power an RCX that has the power
connector


You can do this but it's not recommended. As the RCX 1.0 has a bridge
rectifier on the power input, it's recommended you use a 10v AC supply, to
avoid buring out the diodes.

ROSCO



Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Sat, 18 May 2002 04:19:13 GMT
Viewed: 
1655 times
  
In lugnet.technic, Trevyn Watson writes:
I think you misuderstood what Larry said (or I misunderstood what you
said). I think Larry was saying that you should use the wall wart from
the train speed regulator, which is what Lego recommends.

Yes. That is what I meant. I even believe sincerely that it's what I said. :-)

I am not sure who exactly within LEGO first recommended it but if you dig
hard enough in lugnet.robotics I believe you will find just such a
recommendation.... that you should use the wall wart from the speed reg (not
the speed reg itself) to power your RCX if you so desired.

If you put DC through a bridge you get 100% duty on one side and 0% duty on
the other, possibly resulting in asymmetric heating, contrast with AC which
gives 50-50 duty. Maybe that's what ROSCO was referring to.

However I would like to point out that the wall wart in my hand (from a 4558
I have handy) (which is stamped "Made In China for the LEGO Group", (sans
any (r) symbol, shame on them, but I digress)) takes in 120V AC & .12 A and
puts out 11 Volts AC & 7VA.

Do wall warts issued for 220 regions put out DC instead? If so that would
tend to be just as likely to burn out the bridge rectifier in the speed
controller if it is expecting AC, would it not? It may be a bit more rugged
than the one in the RCX though.

(and in fact hearsay at the time of the 1.5 introduction was that this was
precisely why it was omitted, that they had too many field returns of the
1.0 RCX with burned out bridge rectifiers... not that it was a cost savings
in manufacturing driven change)

++Lar


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Sat, 18 May 2002 07:28:14 GMT
Viewed: 
1565 times
  
In lugnet.technic, Larry Pieniazek writes:
In lugnet.technic, Trevyn Watson writes:
I think you misuderstood what Larry said (or I misunderstood what you
said). I think Larry was saying that you should use the wall wart from
the train speed regulator, which is what Lego recommends.

Yes. That is what I meant. I even believe sincerely that it's what I said. :-)

I am not sure who exactly within LEGO first recommended it but if you dig
hard enough in lugnet.robotics I believe you will find just such a
recommendation.... that you should use the wall wart from the speed reg (not
the speed reg itself) to power your RCX if you so desired.

If you put DC through a bridge you get 100% duty on one side and 0% duty on
the other, possibly resulting in asymmetric heating, contrast with AC which
gives 50-50 duty. Maybe that's what ROSCO was referring to.

However I would like to point out that the wall wart in my hand (from a 4558
I have handy) (which is stamped "Made In China for the LEGO Group", (sans
any (r) symbol, shame on them, but I digress)) takes in 120V AC & .12 A and
puts out 11 Volts AC & 7VA.

Do wall warts issued for 220 regions put out DC instead? If so that would
tend to be just as likely to burn out the bridge rectifier in the speed
controller if it is expecting AC, would it not? It may be a bit more rugged
than the one in the RCX though.

(and in fact hearsay at the time of the 1.5 introduction was that this was
precisely why it was omitted, that they had too many field returns of the
1.0 RCX with burned out bridge rectifiers... not that it was a cost savings
in manufacturing driven change)

I'd be a little surprised at a bridge rectifier which couldn't accept DC. Many
electronic appliances have them these days so that it doesn't really matter
what kind of wall wart you use, so long as the voltage is in the right range.
The wall wart can supply AC or DC, and it doesn't matter what the polarity of
the DC is.

Frank


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Sat, 18 May 2002 19:38:53 GMT
Viewed: 
1544 times
  
   The current is going through two silicon diodes though, with attendant
.5 volt drop through each so consider if that will be a problem in this
application.  Likely its not.

In lugnet.technic, Larry Pieniazek writes:
In lugnet.technic, Trevyn Watson writes:
I think you misuderstood what Larry said (or I misunderstood what you
said). I think Larry was saying that you should use the wall wart from
the train speed regulator, which is what Lego recommends.

Yes. That is what I meant. I even believe sincerely that it's what I said. :-)

I am not sure who exactly within LEGO first recommended it but if you dig
hard enough in lugnet.robotics I believe you will find just such a
recommendation.... that you should use the wall wart from the speed reg (not
the speed reg itself) to power your RCX if you so desired.

If you put DC through a bridge you get 100% duty on one side and 0% duty on
the other, possibly resulting in asymmetric heating, contrast with AC which
gives 50-50 duty. Maybe that's what ROSCO was referring to.
)

++Lar



   Tom Napolitano  tomnap@bersama.net


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Sun, 19 May 2002 04:30:06 GMT
Viewed: 
1557 times
  
In lugnet.technic, Larry Pieniazek writes:

However I would like to point out that the wall wart in my hand (from a 4558
I have handy) (which is stamped "Made In China for the LEGO Group", (sans
any (r) symbol, shame on them, but I digress)) takes in 120V AC & .12 A and
puts out 11 Volts AC & 7VA.

Do wall warts issued for 220 regions put out DC instead? If so that would
tend to be just as likely to burn out the bridge rectifier in the speed
controller if it is expecting AC, would it not? It may be a bit more rugged
than the one in the RCX though.

Ooops! Silly me!

Yes, the Australian (240v) train reg adapter is also 10v AC, so fine to use
with RCX.

ROSCO


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Sun, 19 May 2002 04:34:48 GMT
Viewed: 
1914 times
  
In lugnet.technic, Frank Filz writes:
(and in fact hearsay at the time of the 1.5 introduction was that this was
precisely why it was omitted, that they had too many field returns of the
1.0 RCX with burned out bridge rectifiers... not that it was a cost savings
in manufacturing driven change)

I'd be a little surprised at a bridge rectifier which couldn't accept DC. Many
electronic appliances have them these days so that it doesn't really matter
what kind of wall wart you use, so long as the voltage is in the right range.
The wall wart can supply AC or DC, and it doesn't matter what the polarity of
the DC is.

The main problem comes from the heat generated. This isn't a problem, unless
you're driving motors fairly constantly with your RCX, but can eventually
cause the diodes to break down.

Of course, when one half of the rectifier goes, you can always reverse the
supply polarity & use the other half, until it goes too!

ROSCO


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Mon, 20 May 2002 17:39:27 GMT
Viewed: 
998 times
  
I've got http://guide.lugnet.com/set/9753 with a AC/DC-plug.
Works fine for me to power 9V motors.
/Pehter

Steven lane wrote:

I find batteries a pain, especially as there output isn't constant over
their lifetime, therefore I'd love to be able to power my motors from the
mains. I'd like to know what methods their are are doing this. I'd prefer a
purist option but I do know which end is the dangrous one on a soldering
iron. It also has to work in the UK, home of the three pin plug.

Ta

Steve



Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Mon, 20 May 2002 18:31:44 GMT
Viewed: 
1599 times
  
In lugnet.technic, Pehter Abrahamsson writes:
I've got http://guide.lugnet.com/set/9753 with a AC/DC-plug.
Works fine for me to power 9V motors.
/Pehter

Steven lane wrote:

I find batteries a pain, especially as there output isn't constant over
their lifetime, therefore I'd love to be able to power my motors from the
mains. I'd like to know what methods their are are doing this. I'd prefer a
purist option but I do know which end is the dangrous one on a soldering
iron. It also has to work in the UK, home of the three pin plug.

One other thought here (and I'm not sure how "good" it is for the motors and
I know that efficiency is not the best) is that you will note if you connect
two motors together with the typical electrical connection wire (with no RCX
in the system) that if you twist the shaft of one motor, it will act just
like a generator and will make the second motor turn.  I've been thinking
about how to use this to somehow GENERATE alternative "power" for my RCX
controlled legos and have a motor provide all the current.  Say a windmill
or water wheel or spring or something.  Anyone done something like this?

-Jeff McClain


Subject: 
Re: Powering motors from the mains
Newsgroups: 
lugnet.technic, lugnet.robotics
Date: 
Tue, 21 May 2002 07:41:52 GMT
Viewed: 
1866 times
  
The problem I see is that you don't have anything that is regulating the
outtake from the motor so you may burn of the thin threads inside.

One other thought here (and I'm not sure how "good" it is for the motors and
I know that efficiency is not the best) is that you will note if you connect
two motors together with the typical electrical connection wire (with no RCX
in the system) that if you twist the shaft of one motor, it will act just
like a generator and will make the second motor turn.  I've been thinking
about how to use this to somehow GENERATE alternative "power" for my RCX
controlled legos and have a motor provide all the current.  Say a windmill
or water wheel or spring or something.  Anyone done something like this?

-Jeff McClain


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