How can I make a transformer so my american kitchen appliance can work in the UK

[Zero999]

The motor will more than likely work on DC.

The trouble is that the required DC voltage to run is safely will be less than that of he AC voltage because the inductance of the windings will no longer limit the current. So to run a 120VAC motor on DC, you might need 60V which makes it more difficult again.

[Simon]

why would that be ? if it is a motor with brushes wouldn't it make no difference ? I ran a drill once off 220 VDC by using a rectifier with no problem, it ran as it did before.

[Zero999]

It depends on the motor.

A universal motor will have a stator winding which will either be in series or parallel with the armature. If it's run off AC, the inductance of the coil and to a lesser extent the armature will limit the current. If the motor is run from DC, the inductance won't matter so the current in the stator coil will only be limited by the internal resistance which is why I suggested reducing the voltage.

I've tried reducing the speed of a series wound vacuum cleaner motor by connecting a half-wave rectifier in series and was at first surprised that it didn't reduce the speed as much as I would have thought but I put this down to the coil's inductance.

I've never tried running a universal motor from a full wave rectifier but I imagine that I would have to use a lower voltage to get the same speed and torque.

I don't know your drill might have a PM motor and already have a rectifier built-in? Or perhaps the inductance limited the pulsed current from the rectifier?

[Simon]

Well dosen't the motors brush unit cause the current to be reversed continuosly creating the effect of AC ?

are you saying that it "sounded" to you that a motor with a diode in series was not much slower ? you would only really know by actually measuring it.

my drill was a standard motor with field and armature windings and the brushes

[Zero999]

I only went by sound, so it might've been running at half the speed, I didn't actually measure it.

[Mechatrommer]

just get a big 240V to 120V transformer. goto elec. shop and ask. i used to fool around with transformers (smaller one, but for bigger one i think theoritically the same, it just depend on the transformer power rating). at the very most, when u shorted the transformer output, it will get hot, red and eventually melted away. just dont fool around with the main side (input) of the transformer, u will have a big explosion, even bigger if u dont have circuit breaker protection in your house. if u use underrated transformer, it will heavily loaded and get hot and fail fairly quickly, but if you use larger one, no problem at all. even at the same rated transformer and equipment, transformer will get hot. i used to put fan to cool it down and live longer, thats how high end adapters are doing. if u want to output DC, then you'll have to have support circuitry, rectifier and stabilizer caps. but as the thread owner just simply want to use 130V appliance on 240V main, then a single big 1:2 stepdown transformer will do the trick. for AC motor, pls dont rectify the AC supply, AC motor needs AC supply. same thing with DC motor needs constant voltage supply to work perfectly, its just their design and architecture in amarture and winding that requires those kind of supply. just my 2 cents opinion.