Resistor vs transformer

[Weinberger Hans]

Hi ... I need to convert 230V to 110V. I was wondering whether a 2.4K
resistor with the right power rating would be a more cost/space
effective solution versus a transformer. My load consumes 6 Watts.
What sort of resistor should I use? Wire wound? Carbon?

The 120Watt consumption of the resistor makes me uncomfortable. Are
there any cheap SMPS or light transformers that would work better?

Hans

 

[Phil Allison]

"Weinberger Hans"

** Beware: Kraut imbecile

Hi ... I need to convert 230V to 110V. I was wondering whether a 2.4K
resistor with the right power rating would be a more cost/space
effective solution versus a transformer. My load consumes 6 Watts.
What sort of resistor should I use? Wire wound? Carbon?

** All depends on the application - dickhead.

The 120Watt consumption of the resistor makes me uncomfortable.

** ROTFL !!!

At least he faintly realises the figure is doubtful.

Are there any cheap SMPS or light transformers that would work better?

** All depends on the application - dickhead.

BTW:

Where is the FUCKING LAW that prohibits *absolute idiots* like this
WANKER from POSTING it ?????






......... Phil

 

[Rheilly Phoull]

Hi ... I need to convert 230V to 110V. I was wondering whether a 2.4K
resistor with the right power rating would be a more cost/space
effective solution versus a transformer. My load consumes 6 Watts.
What sort of resistor should I use? Wire wound? Carbon?

The 120Watt consumption of the resistor makes me uncomfortable. Are
there any cheap SMPS or light transformers that would work better?

Hans

The resistor would not take up much space but as you mention the heat would
have to be dissipated. Using a small dual voltage 230/110v transformer as an
auto transformer (the primary windings) is another option but would be more
bulky, however at 6watts it would not have to be very large in physical size
and would have the advantage of covering varying current requirements.

 

[Phil Allison]

"Rheilly Phoull"

The resistor would not take up much space but as you mention the heat
would have to be dissipated.

** But *** NOT *** 120 watts !!!!!!!!!!!!!!!!!!!!!!!!

Using a small dual voltage 230/110v transformer as an auto transformer
(the primary windings) is another option but would be more bulky, however
at 6watts it would not have to be very large in physical size and would
have the advantage of covering varying current requirements.

** Needs to be rated more than 6VA for that job.





......... Phil

 

[[email protected]]

Hi ... I need to convert 230V to 110V. I was wondering whether a 2.4K
resistor with the right power rating would be a more cost/space
effective solution versus a transformer. My load consumes 6 Watts.
What sort of resistor should I use? Wire wound? Carbon?

The 120Watt consumption of the resistor makes me uncomfortable. Are
there any cheap SMPS or light transformers that would work better?

For 50Hz mains a 1.3uF capacitor would do the same job as a 2k4
resistor, and not dissipate very much heat at all - you'd have to find
out the ESR (equivalanet series resistance) to work out how much heat
it would generate.

It isn't clear why you think that your 2k4 resistor would have to
dissipate 120W - if you put it in series with your load, it should
dissipate no more than 7.2W, which is easy enough.
Farnell lists a range of 11W ceramic cased wire-wound resistors that
would do the job for less than $1 though they run pretty hot. Fanrell
also list a couple of ranges of metal-cased wire-wound resistors which
are a little more expensive (around $2) which you can mount on a heat
sink (which can just be a metal plate - 1.5mm thick aluminium or the
like) to get a lower surface temperature.

I wouldn't use a carbon resistor for this sort of job - carbon has a
negative temperature coefficient of resistance, which can lead the
current running through the resistor to concentrate itself in a
relatively narrow hot channel of very low resistance.

Whether this would be a good way to go depends on the nature of your
load - if the 6W is the powr it always dissipates, this could be a
sensible approach. If the 6W is the maximum power it can dissipate, and
it normally draws much less current, your 2k4 resistor (or my 1.3uF
capacitor) might not provide enough protection from the 230V source.

As usual, you need to tell us more about the application.

 

[[email protected]]

"Weinberger Hans"

** Beware: Kraut imbecile



** All depends on the application - dickhead.




** ROTFL !!!

At least he faintly realises the figure is doubtful.





** All depends on the application - dickhead.

BTW:

Where is the FUCKING LAW that prohibits *absolute idiots* like this
WANKER from POSTING it ????

Probably in the same "too hard" basket as the one that would prohibit
discourteous and unhelpful responses like this one.

 

[Ancient_Hacker]

Hello Hans,
It's unlikely that a resistor would be a good choice. It's only
going to dissipate 6 watts, but the voltage regulation will be poor.

Use a small 240 to 120 volt transformer. A 6-watt one will be small
and cheap.

 

[Phil Allison]

" SLOW MAN IDIOT "


** **** off !!!

You asinine, GROSSLY autistic PRICK.






.......... Phil

 

[Phil Allison]

" SLOW MAN GOOGLE FUCKWIT "

For 50Hz mains a 1.3uF capacitor would do the same job as a 2k4
resistor,

** Like FUCKING HELL it will.

It all depends on the application - dickhead.

and not dissipate very much heat at all - you'd have to find
out the ESR (equivalanet series resistance) to work out how much heat
it would generate.

** Sweet **** all - for any suitable film cap.

It isn't clear why you think that your 2k4 resistor would have to
dissipate 120W

** ROTFLMAO !!!!!!!!!!!!!!!!!!!!!!

Not clear ??? ???

The OP is a Kraut moron.

What could be any clearer ???

- if you put it in series with your load, it should
dissipate no more than 7.2W,

** All depends on the application - dickhead.

I wouldn't use a carbon resistor for this sort of job - carbon has a
negative temperature coefficient of resistance, which can lead the
current running through the resistor to concentrate itself in a
relatively narrow hot channel of very low resistance.

** Insane BULL SHITE !!!

Whether this would be a good way to go depends on the nature of your
load - if the 6W is the powr it always dissipates, this could be a
sensible approach. If the 6W is the maximum power it can dissipate, and
it normally draws much less current, your 2k4 resistor (or my 1.3uF
capacitor) might not provide enough protection from the 230V source.

As usual, you need to tell us more about the application.

** It all depends on the application - dickhead.


W A R N I N G !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


*** IGNORE *** the " SLOW MAN " Googling fuckwit - no matter what the
issue !!




........... Phil

 

[Phil Allison]

"Ancient_Hacker"

It's unlikely that a resistor would be a good choice.

** Maybe - maybe not.

All depends on the application - dickhead.

It's only
going to dissipate 6 watts, but the voltage regulation will be poor.

** May matter - or it may not.

All depends on the application - dickhead.

Use a small 240 to 120 volt transformer. A 6-watt one will be small
and cheap.

** Depends if the load draws a large DC component from the AC supply.

The OP is a Kraut * bloody idiot * - so assume NOTHING !!!





......... Phil

 

[The Real Andy]

" SLOW MAN IDIOT "


** **** off !!!

You asinine, GROSSLY autistic PRICK.






......... Phil

YAWN.....

 

[Peter Jakacki]

Hi Hans, I see you have had some helpful replies I take it the 120W
was a typo as you just mentioned 6W and you probably meant 120V drop
(230V-110V). If you do want to use a resistor instead of a transformer
it is best to use a series combo of a resistor and a capacitor. But
before I go any further I should state that I wouldn't recommend this
approach for anything but low-power non-isolated applications. You might
use this if you just needed 10 to 20ma such as in some line-powered
triac circuit.

It is true that a capacitor can be used instead of a resistor but you
have practically no current limiting when it comes to transients, they
will just pass right through the cap and let all the magic smoke out of
your components.

But I think that you probably need to detail your application a little
better because it may be that a transformer solution could be better
suited, but of course this depends upon your load. I sure if you provide
more detail, that among the many replies you may find one you can use.

*Peter*

 

[Phil Allison]

"Peter Jakacki"


** PISS OFF bloody TOP POSTER !!!!!!!!!!!!!!!!

Hi Hans, I see you have had some helpful replies

** Shame yours is not.

I take it the 120W was a typo as you just mentioned 6W and you probably
meant 120V drop....

** Quote from the OP:

" The 120Watt consumption of the resistor makes me uncomfortable.. "

Bit bloody hard to get around the meaning of that - isn't it ????.


BTW:

WHAT is the problem with you jerk-offs just WAITING for the OP to make a
reply ??

You LIKE feeding trolls ???????




......... Phil

 

[Frank Bemelman]

BTW:

WHAT is the problem with you jerk-offs just WAITING for the OP to make a
reply ??

You LIKE feeding trolls ???????

Nah, we're feeding you Don't mind if I laugh, now do you

 

[not i]

" SLOW MAN IDIOT "


** **** off !!!

You asinine, GROSSLY autistic PRICK.

And you, sir, are a needle dicked bug fucker!

 

[not i]

Nah, we're feeding you Don't mind if I laugh, now do you

It's such fun jerking Phillies chain.

 

[Weinberger Hans]

Hi Hans, I see you have had some helpful replies I take it the 120W
was a typo as you just mentioned 6W and you probably meant 120V drop
(230V-110V). If you do want to use a resistor instead of a transformer
it is best to use a series combo of a resistor and a capacitor. But
before I go any further I should state that I wouldn't recommend this
approach for anything but low-power non-isolated applications. You might
use this if you just needed 10 to 20ma such as in some line-powered
triac circuit.

It is true that a capacitor can be used instead of a resistor but you
have practically no current limiting when it comes to transients, they
will just pass right through the cap and let all the magic smoke out of
your components.

But I think that you probably need to detail your application a little
better because it may be that a transformer solution could be better
suited, but of course this depends upon your load. I sure if you provide
more detail, that among the many replies you may find one you can use.

*Peter*

You are right I meant 120V .
Thanks and all those who gave "useful" replies.
Its a wireless receiver unit which calls the fire department in case
of a fire.

Hans

 

[[email protected]]

Thanks and all those who gave "useful" replies.
Its a wireless receiver unit which calls the fire department in case
of a fire.

You probably need to figure out how it converts 120v to whatever it
needs. It may be that you could rip out its power supply and
substitute one for your line voltage.

For a purely resistive load, I think a series diode might work - but
for something with regulation or it's own regulator followed by a
filter cap, probably not.

 

[Frank Bemelman]

** Quote from the OP:

" The 120Watt consumption of the resistor makes me uncomfortable.. "

Bit bloody hard to get around the meaning of that - isn't it ????.

Let's see. Many people think faster than they type. This explains
why we sometimes forget entire words, because we can't keep in
pace with our thoughts.

So, "The 120Watt consumption of the resistor makes me uncomfortable.. "
should perhaps be read as: "The 120V voltage drop and 6 Watt consumption
of the resistor makes me uncomfortable.. ".

 

[Peter Jakacki]

.....adjusting squelch to ignore channel static.....

Hans, you really need to know what type of mains supply the receiver
uses. If it is a transformer then you could perhaps use a choke in
series with it. If it is a SMPS then it may already be designed for 230V
operation or may be able to be configured for 230V (the voltage rating
of the input caps should give you a hint).

I suggest you skip the resistor/cap thing as it may fail and flame and
then how would the fire department be called then? Shouldn't you be
working to some safety standards and compliances for this safety
critical stuff anyway?

*Peter*