NZ-USA Voltage Converter Wiring Diagram or Schematic

[BibBob5]

Need circuit wiring drawing or schematic for 230acv/50c to 115acv/60c
converter.
I'm visiting my daughter in Christchurch, New Zealand who just gave
birth to my 1st grandchild and want to use USA purchased electrical
devices using self-made voltage converters. I will be in NZ another 5
weeks.
When in states, I purchased a Radio Shack Foreign Travel Voltage
Converter (273-1413) that has performed both the plug/pin conversion
and
voltage conversion. Only having one is a PITA and thought I could make
several and attach them to the electric cord for the units to be
converted. One
thing about this RS unit is that the output is only about 88acv instead
of
115acv so when using for recharging batteries, they don't seem to last
as long as when charged in states.
So, any advice for circuit/schematic drawing would be helpful and
appreciated. I do have access to a Dick Smith electronics store in NZ
which is like a Radio Shack so I should be able to obtain parts. I also

know and work with electrical components but don't know how to design
circuits. I'm looking for a relative inexpensive design that I can
build in or around plug/pin converters sold in NZ.
BTW: In most cases, the units are low amp devices, lots of battery
charges, baby monitors (both audio and color-video), no TVs.

Thanks in advance.

 

[Ken Taylor]

Need circuit wiring drawing or schematic for 230acv/50c to 115acv/60c
converter.
I'm visiting my daughter in Christchurch, New Zealand who just gave
birth to my 1st grandchild and want to use USA purchased electrical
devices using self-made voltage converters. I will be in NZ another 5
weeks.
When in states, I purchased a Radio Shack Foreign Travel Voltage
Converter (273-1413) that has performed both the plug/pin conversion
and
voltage conversion. Only having one is a PITA and thought I could make
several and attach them to the electric cord for the units to be
converted. One
thing about this RS unit is that the output is only about 88acv instead
of
115acv so when using for recharging batteries, they don't seem to last
as long as when charged in states.
So, any advice for circuit/schematic drawing would be helpful and
appreciated. I do have access to a Dick Smith electronics store in NZ
which is like a Radio Shack so I should be able to obtain parts. I also

know and work with electrical components but don't know how to design
circuits. I'm looking for a relative inexpensive design that I can
build in or around plug/pin converters sold in NZ.
BTW: In most cases, the units are low amp devices, lots of battery
charges, baby monitors (both audio and color-video), no TVs.

Thanks in advance.

Go down to Dick Smith's and buy a 240-110V step-down transformer. They have
various sizes, so you could buy one just big enough for one device or you
could even buy one big enough for the lot and run an outlet board of it.

Ken

 

[BibBob5]

Thanks Ken, I will try that as soon as I get to Dick Smiths.

This sounds almost too simple and I hope it works.

1. Have you had any experience with doing same in anyway that you could
offer additional advice?

2. Any thoughts as to why the Radio Shack unit was suppling only 88VAC?

With much appreciation.

Bob

 

[Barry Lennox]

Thanks Ken, I will try that as soon as I get to Dick Smiths.

This sounds almost too simple and I hope it works.

1. Have you had any experience with doing same in anyway that you could
offer additional advice?

2. Any thoughts as to why the Radio Shack unit was suppling only 88VAC?

My guess is that RS uses a tiny transfomer that has crappy voltage
regulation. What's the voltage, with, and without a load?

The DSE transformer approach will work fine, but it may become
expensive, or one transformer may a PITA running 110vac leads and
outlet strips from room to room.

I have a lot of USA-sourced power tools and have the woodwork shop
fitted out with a BIG transformer and several outlet strips, but it
would be a real PITA in more than one room.

A more convenient alternative may be to use some cheap NZ 230vac
"Wall-warts" to provide the 9, or 12, or whatever, voltage to the end
unit.

 

[Ken Taylor]

Thanks Ken, I will try that as soon as I get to Dick Smiths.

This sounds almost too simple and I hope it works.

1. Have you had any experience with doing same in anyway that you could
offer additional advice?

2. Any thoughts as to why the Radio Shack unit was suppling only 88VAC?

With much appreciation.

Bob

When we decommissioned one of our US facilities we brought back truck-loads
of gear, some of which was 110VAC only, so yes, been there, done that! Also
done this at home - at home I tend to just power units individually from a
small (but adequate!) step-down transformer. At work we ended up putting in
a mother-of-all-step-down transformers and did a proper distribution. Unless
you had tons of equipment to power, this is probably not the way to go at
home.

As Barry says, the RS unit probably didn't have the 'oomph' to supply
whatever it was you were using. As he says, check whether you can just buy a
new power-pack (wall-wart) which runs off 240VAC, or even check whether your
gear can be switched to 240V, or it may even be 'universal'.

Incidentally, prices are so cheap in NZ these days (for consumer gear) that
in many cases I wouldn't have thought that the freight was worthwhile. If
you still need to truck your gear over here, check first.

Cheers.

Ken

 

[Terry Given]

When we decommissioned one of our US facilities we brought back truck-loads
of gear, some of which was 110VAC only, so yes, been there, done that! Also
done this at home - at home I tend to just power units individually from a
small (but adequate!) step-down transformer. At work we ended up putting in
a mother-of-all-step-down transformers and did a proper distribution. Unless
you had tons of equipment to power, this is probably not the way to go at
home.

As Barry says, the RS unit probably didn't have the 'oomph' to supply
whatever it was you were using. As he says, check whether you can just buy a
new power-pack (wall-wart) which runs off 240VAC, or even check whether your
gear can be switched to 240V, or it may even be 'universal'.

Incidentally, prices are so cheap in NZ these days (for consumer gear) that
in many cases I wouldn't have thought that the freight was worthwhile. If
you still need to truck your gear over here, check first.

Cheers.

Ken

Ah, the joys of paying indonesions $0.35 per month.

most of its crap though.

Cheers
Terry

 

[Barry Lennox]

Need circuit wiring drawing or schematic for 230acv/50c to 115acv/60c
converter.
I'm visiting my daughter in Christchurch, New Zealand who just gave
birth to my 1st grandchild and want to use USA purchased electrical
devices using self-made voltage converters. I will be in NZ another 5
weeks.
When in states, I purchased a Radio Shack Foreign Travel Voltage
Converter (273-1413) that has performed both the plug/pin conversion
and
voltage conversion. Only having one is a PITA and thought I could make
several and attach them to the electric cord for the units to be
converted. One
thing about this RS unit is that the output is only about 88acv instead
of
115acv so when using for recharging batteries, they don't seem to last
as long as when charged in states.
So, any advice for circuit/schematic drawing would be helpful and
appreciated. I do have access to a Dick Smith electronics store in NZ
which is like a Radio Shack so I should be able to obtain parts. I also

know and work with electrical components but don't know how to design
circuits. I'm looking for a relative inexpensive design that I can
build in or around plug/pin converters sold in NZ.
BTW: In most cases, the units are low amp devices, lots of battery
charges, baby monitors (both audio and color-video), no TVs.

Thanks in advance.

As others noted, NZ prices (for crap) have come down a lot in the past
few years, so do a check before you leave. We do have a large chain
here (The Warehouse) that sells asian stuff very cheaply. It's a bit
like a cross between Walmart and "The Christmas Tree Shop" (In New
England, don't know if they are where you are) but not as neatly laid
out. They do have toasters, irons, etc for $12-$20, all made where
english is a second language! Good quality stuff (like Porter Cable
or DeWalt power tools) are still much cheaper in the US.

Barry

 

[keith]

As others noted, NZ prices (for crap) have come down a lot in the past
few years, so do a check before you leave. We do have a large chain
here (The Warehouse) that sells asian stuff very cheaply. It's a bit
like a cross between Walmart and "The Christmas Tree Shop" (In New
England, don't know if they are where you are) but not as neatly laid
out. They do have toasters, irons, etc for $12-$20, all made where
english is a second language! Good quality stuff (like Porter Cable
or DeWalt power tools) are still much cheaper in the US.

Amazingly, they're made in the US too. I much like Porter Cable tools,
BTW.

 

[BibBob5]

Ken, Barry, Terry & Keith,

Thanks for your input and advice; it's worth while to me.

Comments and answers to questions:

1. The RS 88vac is a no-load state, and goes down as I add devices to
a US-power-strip I'm using;
2. Since my daughter/son-in-law will only be in current house several
months, I dont want to do the distribution idea;
3. My daughter received gifts fron US family and friends that dont
understand power differences and my wife didn't want to hurt
feelings...;
4. The devices I have are baby monitors, Digital equipment charges,
and the like.

In closing, isn't there a simiconductor like varistor that could be
used for my purpose?

Bob

 

[Ken Taylor]

Ken, Barry, Terry & Keith,

Thanks for your input and advice; it's worth while to me.

Comments and answers to questions:

1. The RS 88vac is a no-load state, and goes down as I add devices to
a US-power-strip I'm using;
Urk!

2. Since my daughter/son-in-law will only be in current house several
months, I dont want to do the distribution idea;

Good idea.

3. My daughter received gifts fron US family and friends that dont
understand power differences and my wife didn't want to hurt
feelings...;

I have a sister currently in Salt Lake City who is grappling with the
concept that she can't (easily) bring all these nice cheap goodies back
home!

4. The devices I have are baby monitors, Digital equipment charges,
and the like.

In closing, isn't there a simiconductor like varistor that could be
used for my purpose?

No. Basically, it's a transformer or nothing. Replacing wall-warts is a very
good idea if possible, but otherwise you may be out of luck with an
alternative.

Bob

Cheers.

Ken

 

[Terry Given]

Good idea.




I have a sister currently in Salt Lake City who is grappling with the
concept that she can't (easily) bring all these nice cheap goodies back
home!




No. Basically, it's a transformer or nothing. Replacing wall-warts is a very
good idea if possible, but otherwise you may be out of luck with an
alternative.




Cheers.

Ken

or a universal (80-265Vac) input 115Vac inverter ($$$).

Cheers
Terry

PS I've got a 1kVA step-down xfmr to run the things I brought back from
Boston.

 

[Ken Taylor]

or a universal (80-265Vac) input 115Vac inverter ($$$).

Cheers
Terry

PS I've got a 1kVA step-down xfmr to run the things I brought back from
Boston.

We got a 10kVA transformer made here in Auckland, and we've done a full
distribution, but this is commercial so that's a little different. The
universal converter is a good idea "in theory" but as you say, $$$, plus OP
doesn't want to wire a 110V distribution, which is pretty sane thinking
IMHO.

I think he's stuck with small transformer(s).

Cheers.

Ken

 

[Malcolm Moore]

Ken, Barry, Terry & Keith,

Thanks for your input and advice; it's worth while to me.

Comments and answers to questions:

1. The RS 88vac is a no-load state, and goes down as I add devices to
a US-power-strip I'm using;

Hi Bob
Searching the Radio Shack website on the cat # you gave previously
shows that your device is supposed to be capable of 1000W for one
hour, 1600W for 15 mins. Irrespective of the 88V output, the devices
you list below are all low power and wouldn't be expected to cause a
stepdown transformer output voltage to noticably fall.

However, that cat# doesn't seem to still be available. Searching on
travel converters gives a range that includes another 1600W unit cat #
273-1404 that includes the warnings:

"Operates 120VAC heating devices from 240VAC
For irons, lamps, handheld hair dryers
Range 50-1600 watts. Not recommended for products under 50 watts"

Looking at the picture of it shows a device that is quite small
compared to a transformer based unit of that wattage. How big and
heavy is your unit?

My guess is that your Radio Shack unit is a phase control unit (Triac
or SCR) that is not going to work for your use. This would also
explain the 88V reading your meter is giving.

As others have suggested, go and visit DSE or Jaycar.

2. Since my daughter/son-in-law will only be in current house several
months, I dont want to do the distribution idea;
3. My daughter received gifts fron US family and friends that dont
understand power differences and my wife didn't want to hurt
feelings...;
4. The devices I have are baby monitors, Digital equipment charges,
and the like.

In closing, isn't there a simiconductor like varistor that could be
used for my purpose?

That's what I think you already have and it doesn't work for other
than resistive loads. We could also have a discussion about the safety
implications of your device

 

[BibBob5]

Ken, Terry,

Again, thanks for your input.

Malcolm,

The RS unit I have is rather small, (2x2x4) so, as you suggest, it is
the Triac/SCR version (I knew there was a semiconductor unit) and I
guess it can't handle the load of a laptop I brought over and was
thinking of giving to my daughter. The unit overheats because it gives
off an over-heating ordor.

I have tried Dick Smiths and they don't have what I need and the prices
are way too much because they were user freirndly finished products. He
look for a "bare" stepdown and couldn't find one in the 500-10000ma
range which is what I feel is what I need. I also asked the DS sales
person if he could recommend another supplier of "bare" stepdowns but
he didn't know of any. He suggested I try Net. Anyone know of supplier
of stepdowns in Christchurst or NZ that I could have mailed to me that
would be "reasonable." The DS salesperson did't know of the Wall-Wart
units. Again, "cheap" is what I want but probably asking for "too
much."

As usual, you guys and the NewsGroups are great and I always get great
input.

With MUCH appreciation.

Bob

PS: I will try JayCar next, probably should have before this reply...

 

[BibBob5]

Ken, Terry,

Again, thanks for your input.

Malcolm,

The RS unit I have is rather small, (2x2x4) so, as you suggest, it is
the Triac/SCR version (I knew there was a semiconductor unit) and I
guess it can't handle the load of a laptop I brought over and was
thinking of giving to my daughter. The unit overheats because it gives
off an over-heating ordor.

I have tried Dick Smiths and they don't have what I need and the prices
are way too much because they were user freirndly finished products. He
look for a "bare" stepdown and couldn't find one in the 500-10000ma
range which is what I feel is what I need. I also asked the DS sales
person if he could recommend another supplier of "bare" stepdowns but
he didn't know of any. He suggested I try Net. Anyone know of supplier
of stepdowns in Christchurst or NZ that I could have mailed to me that
would be "reasonable." The DS salesperson did't know of the Wall-Wart
units. Again, "cheap" is what I want but probably asking for "too
much."

As usual, you guys and the NewsGroups are great and I always get great
input.

With MUCH appreciation.

Bob

PS: I will try JayCar next, probably should have before this reply...

 

[Fred Bloggs]

I much like Porter Cable tools,
BTW.

 

[Barry Lennox]

Ken, Terry,

Again, thanks for your input.

Malcolm,

The RS unit I have is rather small, (2x2x4) so, as you suggest, it is
the Triac/SCR version (I knew there was a semiconductor unit) and I
guess it can't handle the load of a laptop I brought over and was
thinking of giving to my daughter. The unit overheats because it gives
off an over-heating ordor.

I have tried Dick Smiths and they don't have what I need and the prices
are way too much because they were user freirndly finished products. He
look for a "bare" stepdown and couldn't find one in the 500-10000ma
range which is what I feel is what I need. I also asked the DS sales
person if he could recommend another supplier of "bare" stepdowns but
he didn't know of any. He suggested I try Net. Anyone know of supplier
of stepdowns in Christchurst or NZ that I could have mailed to me that
would be "reasonable." The DS salesperson did't know of the Wall-Wart
units. Again, "cheap" is what I want but probably asking for "too
much."

As usual, you guys and the NewsGroups are great and I always get great
input.

With MUCH appreciation.

Bob

PS: I will try JayCar next, probably should have before this reply...

Bob,

How many do you need? and are you in Christchurch? It looks like you
only need some wall-warts for a few months, right? If so, I can raid
my surplus box and maybe find a few that would suit and you could
borrow. I'm about 30 mins out of ChCh.

Barry

 

[Malcolm Moore]

Ken, Terry,

Again, thanks for your input.

Malcolm,

The RS unit I have is rather small, (2x2x4) so, as you suggest, it is
the Triac/SCR version (I knew there was a semiconductor unit) and I
guess it can't handle the load of a laptop I brought over and was
thinking of giving to my daughter. The unit overheats because it gives
off an over-heating ordor.

I have tried Dick Smiths and they don't have what I need and the prices
are way too much because they were user freirndly finished products. He
look for a "bare" stepdown and couldn't find one in the 500-10000ma
range which is what I feel is what I need. I also asked the DS sales
person if he could recommend another supplier of "bare" stepdowns but
he didn't know of any. He suggested I try Net. Anyone know of supplier
of stepdowns in Christchurst or NZ that I could have mailed to me that
would be "reasonable." The DS salesperson did't know of the Wall-Wart
units. Again, "cheap" is what I want but probably asking for "too
much."

As usual, you guys and the NewsGroups are great and I always get great
input.

With MUCH appreciation.

Bob

PS: I will try JayCar next, probably should have before this reply...

Hi,
I presume the current above is a typo and you meant
500-1000mA?
Check the Jaycar offerings at www.jaycar.co.nz

For bare transformers check
http://www.tsltransformers.co.nz/Our_Products.shtml
and
http://www.ete.co.nz/Products/Transformers/transformers.htm
both are in Auckland.

Don't forget to cost in freight & a box & plug & socket etc.

If you have access to someones junk box you could do the equivalent
with two transformers if you can find two suitable units. One with
230V primary and one with 120V and both with equal secondary voltages
and adequate VA rating.

e.g. 230V > 24V > 24V > 120V

Have you checked that the laptop needs 120V? Many have universal
supplies that handle anything between 100V - 250V.

 

[BibBob5]

Malcolm, Barry, Terry and Ken,

My issue seems resolved... TBD

My daughter took me to a flea market where I was able to get four NZ
(5vdc - 9vdc) chargers and a rather large 115->230 step-up transformer.
I rewired the step-up for stepdown and it looks like it will work for
my needs. The five items cost me $20 NZD; such a bargin. We all have to
remember to include those flea markets in our problem solving
situations...

I really want to thank all of you again for your input, advice, links,
and offer of equipment loans (Barry, yes I'm in CHC).

Bob

PS: Returning to USA/PA next week and still have lots of non-electrical
projects to complete before then.

 

[Bret Ludwig]

2:1 transformers that will "go either way" are a commodity item
anywhere in the world from electrical supply houses. The cost per kVA
goes down as the size goes up. In countries with lower labor costs it
is possible to have one wound specially for a reasonable cost.

Several companies have large toroids with two bifilar windings
intended as the primary for 110 or 220 use prewound for the final user
to put his own secondaries on. They can be used as autoformers to give
50% voltage in many cases.

If a wall wart is involved, it is always better to get a new wall wart
for the local voltage.