Digital Parametric Equalizer Design With Prescribed

A new type of second-order digital parametric equalizer is proposed whose frequency
response matches closely that of its analog counterpart throughout the Nyquist interval
and does not suffer from the prewarping effect of the bilinear transformation near the
Nyquist frequency. Closed-form design equations and direct-form and lattice realizations
are derived.

1. Introduction

Conventional bilinear-transformation-based methods of designing second-order digital parametric
equalizers [1–11] result in frequency responses that fall off faster than the corresponding analog
equalizers near the Nyquist frequency due to the prewarping nature of the bilinear transformation.
This effect becomes particularly noticeable when the peak frequencies and widths are relatively
high. Figure 1 illustrates this effect.
In this paper, we introduce an additional degree of freedom into the design, namely, the gain at
the Nyquist frequency, and derive a new class of digital parametric equalizers that closely match
their analog counterparts over the entire Nyquist interval and do not suffer from the prewarping
effect of the bilinear transformation.
The design specifications are the quantities {f , f , ?f, G , G , G, G }, namely, the sampling rate
s 0 0 1 B

f , the boost/cut peak frequency f , the bandwidth ?f , the reference gain G at DC, the gain G at
s 0 0 1

the Nyquist frequency fs /2, the boost/cut peak gain G at f0, and the bandwidth gain GB (that is, the
level at which the bandwidth ?f is measured.)
All previous methods of designing second-order equalizers assume G1 = G0 (usually set equal
to unity.) In these methods, the bilinear transformation is used to transform an analog equalizer
with equivalent specifications into the digital one. As remarked by Bristow-Johnson [9], all of these
designs are essentially equivalent to each other, up to a different definition of the bandwidth ?f and
bandwidth gain GB . For the equivalent analog equalizer, the quantity G0 = G1 represents the gain
at DC and at infinity, with the latter being mapped onto the Nyquist frequency f /2 by the bilinear
s

transformation.
In the method proposed here, we allow G to be different from G . In particular, we set G
1 0 1

equal to the gain an analog equalizer would have at f /2 if it were not bilinearly transformed. This
s

condition on G , together with the requirements that the gain at DC be G , that there be a peak
1 0

maximum (or minimum) at f0, that the peak gain be G, and that the bandwidth be ?f at level GB ,
provide five constraints that fix uniquely the five coefficients of the second-order digital filter.
The resulting digital filter matches the corresponding analog filter as much as possible, given
that there are only five parameters to adjust. The matching is exact at f = 0, f , f /2, and the two
0 s

filters have the same bandwidth ?f . These design goals are illustrated in Fig. 2.

†Presented at the 101st AES Convention, Los Angeles, November 1996, and published in JAES, vol.45, p.444, June 1997.

1

what is a capacitor and How to Replace Capacitor

what is a capacitor and How to Replace Capacitor

This is capacitor replacement tutorial video. This video describes how to replace the damage capacitor with new capacitor. The capacitor has two important reading, they are capacitance and voltage. The capacitance shows how much energy that can hold that given voltage. The voltage reading shows the maximum voltage that capacitor can handle before it exploded. To replace the damage capacitor, we must replace it with capacitors that has the same capacitance and the same or higher voltage.

100W Audio Amplifier Transistor used BDW83D - BDW84D circuit diagram

100W Audio Amplifier Transistor used BDW83D - BDW84D circuit diagram         

Here 100 watt power audio amplifier which using power transistor BDW83D and BDW84D. Copyright belong to Smart Kit.

Schematic diagram:

Component part list:

R1 = 1,2 K                                   D1 = 1N4002-7  

R2 = 0,47 OHM                           D2 = 1N2002-7  

R3 = 220 OHM                            D3 =  1N4148     

R4 = 3,9 K                                   D4 = 1N4148      

R5 = 2,2 K                                   D5 = 1N4148      

R6 = 2,2 K                                    D7 = 1N4148     

R7 = 10 K                                    D8 = 1N4148      

R8  = 4,7 K                                  Q1 = BDW84D   

R9 = 150 OHM                            Q2 = BD829       

R10 = 39 OHM                            Q3 = BC546       

R11 = 3,3 K                                  Q4 = BC556      

                                 

20 WATT FLUORO INVERTER used tip3055

20 WATT FLUORO INVERTER used tip3055

This circuit will drive a 40 watt fluoro or two 20watt tubes in series.
The transformer is wound on a ferrite rod 10mm dia and 8cm long.

The wire diameters are not critical but our prototype used 0.61mm wire for the primary and 0.28mm wire for the secondary and feedback winding.
Do not remove the tube when the circuit is operating as the spikes produced by the transformer will damage the transistor.
The circuit will take approx 1.5amp on 12v, making it more efficient than running the tubes from the mains. A normal fluoro takes 20 watts for the tube and about 15 watts for the ballast.
source : http://talkingelectronics.com/projects/200TrCcts/200TrCcts.html

SAMSUNG LE32A430 user guide

Precautions When Displaying a Still Image
A still image may cause permanent damage to the TV screen.
•   Do not display a still image on the LCD panel for more than 2 hours as it can cause screen
image retention.
This image retention is also known as "screen burn".  
To avoid such image retention, reduce the degree of brightness and contrast of the screen
displaying a still image.
•      Watching the LCD TV in 4:3 format for a long period of time may leave traces of
borders displayed on the left, right and center of the screen caused by the differen
of light emission on the screen. Playing a DVD or a game console may cause a si
effect to the screen. Damages caused by the above effect are not covered by the Warranty.
•   Displaying still images from Video games and PC for longer than a certain period of time m
produce partial after-images.
To prevent this effect, reduce the ‘brightness’ and ‘contrast’ when displaying still images.

download SAMSUNG LE32A430 user guide
key word :

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SAMSUNG LE32A430 user guide