Wednesday, June 24, 2009

Power Amplifier 45W with HEXFET IRF9540,IRF540


A ideal solution for the make a good, low cost power amplifier. It�s a ideal solution for the creation a system of home cinema. The preamplifier and the driver support in a operational amplifier [IC1]. The voltage fall in resistors R5 and TR2/R6, drive the output FET’s gates and is proportional with the input signal level. Transistors Q1-2 function as voltage stabilizers in the supply lines, but ensure also the essential voltage fall, because the IC1 it should not they are supplied with voltage bigger ± 18V. …

Part List
R1=47Kohm C1-2-6-7=100nF 100V MKT Q5-6=IRF9540
R2-12=1Kohm C3-4=22uF 25V Q7-8=IRF540
R3-4=3.3Kohm C5=220pF styroflex TR1=5Kohm trimmer multiturn
R5=1.2Kohm C8-9=4700uF 63V TR2=1Kohm trimmer multiturn
R6=[1.2Kohm] 820ohm *See text C10=1uF 100V MKT F1-2=fuse 3A
R7=270ohm D1-2=15V 0.5W zener J1=2pin connector 2.54mm step
R8=220ohm IC1=LF411orAD711or LF351 J2=5pin connector 5mm step
R9=27Kohm Q1=BC550C
R10-11=22Kohm Q2=BC560C All Resistors 1/4W 1% metal film
R13-14-15-16=150ohm Q3-4=BC547B



Read More Source:
http://users.otenet.gr/~athsam
Thank you.
[read here...]

170 Watt Class D Audio Power Amplifier with LM4651 and LM4652

Description
The IC combination of the LM4651 driver and the LM4652 power MOSFET provides a high efficiency, Class D Amplifier solution
This circuit is ideal for car booster amplifier, active speaker/subwofer, home theater, or PC’s multimedia sound system. The maximum efficiency 85% is obtained at 125W power output condition। The total harmonics distortion is 10% at full power output of 170W। For better fidelity, the THD at 10W is only 0।3% for 10-500Hz input signal driving 4 ohm speaker
  • Conventional pulse width modulation
  • Turn-on soft start and under voltage lockout
  • 50kHZ to 200kHz switching frequency range
  • Externally controllable switching frequency
  • Integrated error amp and feedback amp
  • 15 Lead TO220 isolated package
  • Self checking protection diagnostic
  • Over modulation protection (soft clipping)
  • Short circuit current limiting and thermal shutdown protection.

    The power supply voltage cannot exceed (+-) 22V, and also, the output stage will be turned off when the supply voltage drops under 10.5V to prevent under-voltage failure both for the circuit and for the battery (if implemented for car audio application).
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Tuesday, June 23, 2009

2 x 25 W class-D power amplifier with TDA8922.

General descriptionShow

The TDA8922 is a high efficiency class-D audio power amplifier with very low dissipation. The typical output power is 2 X 25 W.

The device is available in the HSOP24 power package with a small internal heatsink and in the DBS23P through-hole power package। Depending on the supply voltage and load conditions, a very small or even no external heatsink is required. The amplifier operates over a wide supply voltage range from +-12.5 to +-30 V and consumes a very low quiescent current.






FeaturesShow
High efficiency (~90pct)
Operating supply voltage from +-12.5 to +-30 V
Very low quiescent current
Low distortion
Usable as a stereo Single-Ended (SE) amplifier or as a mono amplifier in Bridge-Tied Load (BTL) Fixed gain of 30 dB in Single-Ended (SE) and 36 dB in Bridge-Tied Load (BTL)
High output power
Good ripple rejection
Internal switching frequency can be overruled by an external clock
No switch-on or switch-off plop noise
Short-circuit proof across load and to supply lines
Electrostatic discharge protection
Thermally protected
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Tuesday, June 9, 2009

Saturday, June 6, 2009

FET Audio Mixer






Description
This simple circuit mixes two or more channels into one channel (eg. stereo into mono). The circuit can mix as many or as few channels as you like and consumes very little power. The mixer is shown with two inputs, but you can add as many as you want by just duplicating the "sections" which are clearly visible on the schematic.
Partlist
2x 10K Pot (R1, R3) 2x 100K 1/4 W Resistor (R2, R4) 1x 6.8K 1/4 W Resistor (R5) 3x 0.1uF Capacitor (C1, C2, C3) 1x 2N3819 Junction FET (Q1) 1x Wire, Shielded (Metal) Case, Phono Or Other Plug For Output
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Wednesday, June 3, 2009

One tube (6AU6) radio


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