Power Conditioner Nikola

In times of energy transition, one type of hi-fi equipment is becoming increasingly important: mains filters resp. power conditioners! Fifty years ago, these would not have sold. Back then, our electricity was made by generators. 3000 rpm, perfect sine wave 50 Hz, without harmonics. LED lights, switching power supplies, and solar power did not yet exist.
The load caused by harmonics has become so severe that grid operators are having problems staying within the permitted distortion limits for electricity.

In the Nikola, a central 1:1 symmetrical transformer ensures effective filtering of these disturbances. The power filter is deliberately kept as simple as possible. No bling bling. Only the bare essentials, but these as good as possible. No automatic switch-on, but a two-stage mechanical switch. No LED for operation display, but glow lamps. No cheap input jacks and output sockets, but high-quality ones from Furutech. And definitely no completely nonsensical digital displays for current flow and voltage values.

• input: 230V / 50Hz; IEC C14 with fuse holder 5 x 20mm
• nominal power: 2,000 VA
• idle power consumption: 6VA
• maximum current: 10A
• efficiency: > 96%
• output: 230V / 50Hz; 6 x Schuko
• Furutech input and output sockets
• high-quality housing made of acrylic and pertinax
• dimension: B300 x H200 x T400
• weight: 25kg
• special requests expressly possible

Technology

Unlike almost all other suppliers, I use a cut tape core as the centrepiece for the symmetrical transformer. I am convinced that a toroidal transformer is not ideally suited for this task.

The Symmetry

One of the biggest advantages of this mains filter is that it balances the voltage at the output. The unbalanced voltage from the wall socket (0V - 230V) is transformed to: 115V - 0V - 115V. All common mode interference coming from the wall socket is thus eliminated at the output of the Nikola. The more ‘symmetrical’ the transformer is designed, the better this cancellation is. This can be clearly seen in the pictures: two coils, each with half the primary and half the secondary winding. The coils are wound as identically (symmetrically!) as possible. This is not possible with a toroidal transformer, as there are no two separate coil bodies.

The Air Gap

In order to prevent high-frequency differential mode interference from being transmitted to the secondary side as much as possible, the stray inductance must be increased and the stray capacitance reduced. This is achieved by means of two air gaps. One is in the iron itself, which is referred to as a ‘cut’ strip core. The other is between the primary and secondary coils. Here, spacers are used to create a large gap between the windings. This is not possible with a toroidal transformer. The first air gap does not exist due to the principle, and I cannot think of a way to implement the second one in a toroidal transformer.

The Shield Winding

There is a shield winding between the primary and secondary windings. These additionally reduce the transmission of high frequencies to the secondary side. The two shields are wound in such a way that the induced voltage cancels itself out.