Circuit Wiring

The order of 4 or sealed rear chamber bandpass system is essentially a system of watertight enclosures with the addition of an acoustic filter for the driver. The resulting system usually provides a lower cut-off frequency, the compromise that a larger case. The space can be reduced by two drivers in isobaric configuration.

4th-order bandpass systems generally show better able to handle the functions that the other major systems are considered. The transient response and is second only to the sealed enclosure systems, making it a good choice for subwoofer applications.

Since all output 4th order bandpass system is via the port, the largest diameter possible for the port area should be used to minimize noise from the port. The ports must be incinerated where possible, for the same reasons.

4th order Isobaric Subwoofer Box Design

The 4th order bandpass system rarely allows a perfect bandpass response - there is usually an out-of-band noise present in the production. A notch filter can be used simply to reduce the noise as audible. Otherwise, a lowpass filter used in series with the driver, but the in-band response system may be affected if this approach is taken.

As the speaker sound 4th order band pass issued by the openings or ports on the port side of the box, the port noise inevitable.

This unwanted noise can be minimized by a notch filter and the largest diameter possible for the port of the area should definitely be used. Another option is to burn the ports of the 4th order bandpass room as this will certainly help to reduce unwanted extra from the subwoofer.

WOOFER / MID MODEL - 5MP60 / N

Specifications :

Source : alectronics.blogspot.com

The above is an amplifier circuit using supply voltages from 6 volts DC to 12 Volt DC. Power output of the amplifier is quite low with only 1 Watt 8 ohm impedance. You can apply this to the audio signal amplifiers that require strengthening are not so large as in the pocket radio.

Part List :
R1 =  100K
R2 = 39R
R3 = 100R
C1 = 100nF
C2 = 100uF
C3 = 100uF
C4 = 100uF
C5 = 470uF
C6 = 100nF
C7 = 68pF
C8 = 1nF
C9 = 47uF
IC = SFC2790C

source:LINK

A very simple 6 channel low cost led driver electronic circuit project can be designed using the MCP34845 LED drivers manufactured by Free scale Semiconductor.The MCP34845 LED drivers operates from 5 to 21 volts and is specially designed for use in back lighting LCD displays from 10" to 17"+ for devices like : PC Notebooks , Net books , Picture Frames , Portable DVD Players , Small Screen Televisions , Industrial Displays , Medical Displays , etc.

6 Channel LED Driver Circuit Diagram



The MCP34845 LED drivers is capable of driving up to 16 LEDs in series in 6 separate strings.PWM dimming is performed by applying a PWM input signal to the PWM pin which modulates the LED channels directly.Main features of this driver circuit project are : input voltage of 5.0 to 21 V , boost output voltage up to 60 V, 2.0 A integrated boost FET , fixed boost frequency - 600 kHz or 1.2 MHz , OTP, OCP, UVLO fault detection , LED short/open protection , programmable LED current between 3.0 mA and 30 mA .