transformer 110 to 240

[mystraightroad]

Hello

total novice at this so I'm hoping someone can help. I have a USA
appliance and the spec is given as:

INPUT 110 volt fuse protected
OUPUT 12 volt DC as 3 amps, circuit breaker protected

the plug is a USA 3 pin type (2 thin plugs at bottom, one round plug at
top). Am I right in thinking that the round one means the appliance is
grounded/earthed?

I can't find anything that relates to watts. Do I calculate this by 12
(volts) * 3 (amps) to give me 36?

Also, if I buy a transformer which is too low (Maplins do one at
45watts) will I blow the transformer, the appliance, or both!?

Many thanks

 

mystraightroad wrote:
:

INPUT 110 volt fuse protected
OUPUT 12 volt DC as 3 amps, circuit breaker protected

the plug is a USA 3 pin type (2 thin plugs at bottom, one round plug
at
top). Am I right in thinking that the round one means the appliance
is
grounded/earthed?

Yes.

I can't find anything that relates to watts. Do I calculate this by
12
(volts) * 3 (amps) to give me 36?

Yes.

Also, if I buy a transformer which is too low (Maplins do one at
45watts) will I blow the transformer, the appliance, or both!?

No. But why buy a transformer to power an adapter? Just but a 12V 3A
adapter for 230V input. Maplins sell 'em.

 

[mystraightroad]

thank you so much for your replies.

Ok, I have a feeling this is a stupid question but here goes....

If we assume that the draw is twice the max output (75w) would it hurt
if I were to use a transformer rated at 300w rather than one at 100w.
A friend has said they will lend me a 300w transformer, I'm just
concerned it might be too strong.

 

[Dwayne]

"mystraightroad" <mystraightroad@hotmail.com> wrote in message
news:1115406431.877205.181570@g14g2000cwa.googlegroups.com...

Hello

total novice at this so I'm hoping someone can help. I have a USA
appliance and the spec is given as:

INPUT 110 volt fuse protected
OUPUT 12 volt DC as 3 amps, circuit breaker protected

the plug is a USA 3 pin type (2 thin plugs at bottom, one round plug at
top). Am I right in thinking that the round one means the appliance is
grounded/earthed?

Yes.

I can't find anything that relates to watts. Do I calculate this by 12
(volts) * 3 (amps) to give me 36?

Correct.

Also, if I buy a transformer which is too low (Maplins do one at
45watts) will I blow the transformer, the appliance, or both!?

Just buy a power adapter with a 12 Volt output capable of at least 3 Amps.
For example if you buy a 48Watt adapter with a 12V, it can suppy a maximum
current of 48/12= 4A. So you can connect any 12V device, and draw a MAX of
4A. There is no minumum draw, your 3A device will work fine, so will a
device rated at 12V and 2A or 1A or 500mA, etc...

Dwayne