Black Gate
Technical Report No. 89 

Unconventional BG-WK POWER TANK is born: suppresses noise completely!

Remove an unavoidable self-interference occurred in a common power supply handles pulse: The most important process for your set!

A lot kind of electronic equipment which handles with pulse such as a television has a cathode ray tube imaging display device inside. 
Without exception, it has a horizontal fly back circuit for an electron-beam deflection of fairly large voltage.  In fact, this is the biggest source of noise generation.
The noise invades other numerous circuits connected with a same power supply directly, and self interference occurs inside because the noise is unexpectedly larger than that of coming from outside.

(1) Removing a harmful effect on picture quality especially for color reproducing circuit
While horizontal output pulse flies back, a large ringing power including odd numbers harmonics generates. (See Figure 1)
This is the cause of noise generation, and the ringing power goes through a power supply and hits other circuits directly. 
It damages Y signals enormously that deciding the picture quality, and also deteriorates the color signals of I  and Q and the operation of a phase detecting circuit particularly.

A conventional electrolytic capacitor for smoothing noise is polarized, so it can smooth noise in only one direction.  The opposite direction is left uncontrolled, and makes the performance of other circuits connected with the same power supply bad.
Then, to replace such a capacitor with non-polarized Black Gate, the noise has vanished completely and picture quality has improved drastically because BG can work in the both directions. Now, Black Gate has got much attention for the perfect non-polarized operation of wide voltage range by even a single piece.

(2) The new brand BG-WK, the revolutionary structure
 This Black Gate looks like a polarized electrolytic capacitor in appearance, yet it is entirely different. The inside is asymmetrical and non-polarized structure which has two different working voltages: the +pole is 200V and the -pole is 100V. 

This is unconventional as well as the most reasonable structure because when a pulse voltage at its peak 100V adds to the ringing power that superposes on a driving DC voltage of around 130V that is rectified by 100V power supply can be smoothed and  bypassed as no distortion, low loss, and ultra high speed. (See Figure 2)

At last, Jelmax has completed a state-of-the-art BG-WK 200V 220uF: high performance and very efficient capacitor for various characteristics in the same size as a conventional one.
Ordinarily, a ringing noise superposed on a conventional smoothing capacitor is all under 100V, therefore BG-WK can eliminate the noise completely. 
This is certainly the indispensable weapon against self-interference which HDTV has to face in the near future. We are going to explain why is the capacitor a power tank type in the next issue for a switching power supply.

(3) The power increases a lost and the life becomes longer by several times
In a conventional capacitor, the reverse pulse is directly absorbed inside and becomes loss power that would make the temperature of electrolyte rises. 
It dries up faster and the life of the capacitor becomes shorter. TV monitors, image receiving devices and PCs, all of them which are very frequently used suffer much for this.
On the other hand, the inner loss of BG-WK is the only E.S.R. due to a non-polarized structure, so the temperature rises just a little.
The electrolyte inside is consumed as less as 1/100 compared to conventional ones. Therefore the power has increased and the life has become as much as 3 to 5 times longer!
We believe that these are wonderful new for TV stations that have to spend a lot of money to maintain VDT, for companies using OA, and medical institutions using high class medical equipment.

Figure 1:Horizontal Output Pulse Waveform
Figure 2: Horizontal Output Circuit for TV