Transformer problems from 240Vac to 110Vac.?
Answer:
Assuming it is an isolation transformer, the answer might depend somewhat on what you are measuring with, it it is a digital multimeter with 10 megohm or higher input impedance you could be measuring leakage or the effects stray capacitance. You might try putting a load across the input of the voltmeter, maybe something like 10 kilo ohms or so, if the reading is dramatically reduced, the the source is probably stray capacitance, if the reading is not significantly reduced you have a leak capable of delivering some current, which is probably a faulty transformer. If it is an autotransformer (and the case is grounded), there may be a problem with your ground.
You might also try disconnecting the device form the power source and measuring the resistance between the secondary terminals to the case, secondary to primary, and primary to case, if you get a reading less than "over range" then you probably have a defective transformer (leaky or shorted)
A double insulated transformer is one that has a second layer of insulation in addition the the enamel on the wire, often the the primary and secondary are wound on seperate sections of a plastic (insulating) bobbin (also called a split bobbin transformer)
I'm no electrical engineer, but what I believe your are witnessing is inductance.
http://hyperphysics.phy-astr.gsu.edu/hba...
Basically there has to be a difference from one lead to the other, because your are transferring power. If there was no voltage drop, there would be no way for power to be transfered to the other winding.
Double insulated transformer--
http://www.freepatentsonline.com/5200731...
i guess it shd show it as close to 110V as possible. I blv it mgiht be faulty. Can you check with the manufacturer / shop dealer?
It is probably an isolation transformer. The secondary winding is not connected to ground or to the transformer chassis, so there should be no voltage between either secondary lead and the chassis. Since there is some capacitive coupling and thus a high impedance connection between the primary winding and the transformer frame and between the primary and secondary winding. The secondary lead that has the lowest impedance stray coupling to the chassis will have the lowest voltage to the chassis. The secondary winding that has the lowest impedance to the hot side of the primary winding will have the highest voltage to the chassis.
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