Current transformer

Current transformer

      A current transformer consists of primary and secondary coils of wire wrapped around a core, usually made of steel or a nickel alloy. Transformer winding are electrically insulated from each other and from the core. The winding connected to the power supply is called primary winding. The transformer winding in which current is induced is called secondary winding.

    As current passes through the primary winding, an electromagnetic field is produced which induces a current in the electrically isolated secondary winding. The number of coils in a winding determine the amount of current and voltage in the circuit. By altering the coil ratio between the primary and secondary winding, a current transformer can alter the current, either stepping it up or down, while conserving power.

For this project, the current transformer is used to step up the voltage at low current. the secondary winding will be connected to the circuit while the primary winding connected to the electrode thus to the patient.

The above two pictures is a transformer with 1.2 VA as for power resulted for this transformer. This transformer had been bought at RS online. As for the picture below, bought from Pasar road. Looks like messy component but it gives 0.9 VA power for the transformer.

Both type of above transformer is not very suit to used in this project because the power needed is only 100 mA to 150 mA but it still can be tested. Thus, the suitable transformer still in finding process.