Wednesday, March 21, 2012

Cable TV amplifier With 2 Transistors

Cable TV amplifier With 2 TransistorsThis is a actual simple cable TV amplifier application two transistors. This amplifier ambit is a lot of acceptable for cable TV systems application 75 Ohm coaxial cables and works accomplished up to 150MHz. Transistor T1 performs the job of amplification. Up to 20dB accretion can be accepted from the circuit.T2 is active as an emitter addict to access accepted gain.

Notes.

  • The circuit can be assembled on a Vero board.
  • Use 12V DC for powering the circuit.
  • Type no of the transistors are not very critical.
  • Any medium power NPN RF transistors can be used in place of T1 and T2.
  • This is just an elementary circuit. Do not compare it with high quality Cable TV amplifiers available in the market.
[read here...]

Sunday, March 4, 2012

MSK5012 Adjustable Voltage Regulator 10A

MSK5012 is a awful reliable adjustable voltage regulator.Whose achievement can be programmed application two resistors. The regulator has a actual low dropout voltage(0.45v @10A )due to the acceptance of MOSFT with actual low Rds (ON) as the centralized alternation canyon element.The MS5012 has a top akin of accurateness and ripple bounce is about 45dB. It is accessible in a 5 pin Sip amalgamation that is electrically abandoned from the centralized circuitry. This accord us the abandon to fit the IC anon to the calefaction bore and this array of absolute heatsinking improves the thermal dissipation. 

The achievement voltage of this circuit is adjustable from 1.3v to 36v DC.Resistors R1 and R2 are acclimated for programming the achievement voltage. For all applications, amount of R2 is anchored to 10K. The accord amid R1,R2 and achievement voltage Vout is according to the blueprint R1=R2(Vout/1.235)-1. C1 is a clarify capacitor which is aswell a allotment of the aboideau drive circuit of the centralized alternation canyon MOSFET. About three times the ascribe voltage will arise beyond this capacitor and so the its voltage appraisement have to be called accordingly.C2 is the ascribe clarify capacitor while C3 is the achievement clarify capacitor.
[read here...]

Wednesday, February 1, 2012

CLASS AB BJT 100W Hi-End AUDIO AMPLIFIER CIRCUITS

Symasym5, is a "cute" power amplifier, designed with quality but still low price in mind. This resulted in a ClassAB BJT amplifier, using only TO92 transistors for input and VAS, with a reasonable part count. The topology used is well known and consist of a single diffamp for input, plus a 2nd diffamp with current mirror for VAS. This is followed by normal darlington EF outputstage using modern high beta devices. The circuit uses large amounts of feedback over the whole audioband and an unconventional feedback compensation scheme. Right now symasym is designed to be driven directly from a CD/DVD-player, simply place a 22k poslog stereo pot between player and symasym. (as voltage divider)
Update
The at least change is to reduce C14 from 22pF to 10pF, but i recommend to follow Pavel's advice.
I recommend C14 with 10pF also for MJLs, this increases safety margin.
Do not forget to read Pavel's Review! A very promising evaluation of the qualities to be expected from symasym. Thanks Pavel !
Another update are the resistors R31/32 to be increased from 22ohm to 47ohm. Symasym5_3 is an update of v5.2, with an improved board layout concerning power gnd,
[read here...]

Monday, December 12, 2011

400 and 600 WATT AMPLIFIER WITH IRFP460 MOSFET CIRCUITS

Actrk 400/600 Watt
Two versions of a robust module capable of delivering high powwer for extended periods.  The Actrk400 uses 6 n-channel Mosfets in the output stage to deliver around 400 watts into 4 ohms while the Actrk600 uses 12 n-channel Mosfets in the output stage to deliver power in excess of 600 watts into 4 ohms.  One constructor has achieved almost 900 watts with the Actrk600 layout using 12 IRFP460 Mosfets.
Actrk 600W schematic

[read here...]

Saturday, December 3, 2011

BA5406 Stereo Amplifier Circuit

BA5406 Stereo Amplifier Circuit
In the circuit diagram shown, BA5406 is configures to deliver 5×2 watts into 4 ohm loudspeakers at a supply offer voltage of 9 volts. Capacitor C3 is a power supply filter capacitor. C11 and C12 are input DC decoupling capacitors for the left and right channels. C3 and R2 forms a Zobel network for the left output whereas C6 & R3 forms identical for the correct channel.

Purpose of the Zobel network is to cut back oscillations and improve high frequency stability of the amplifier. Potentiometers R5 and R6 serves as the quantity control for the left and right channels. CapacitorsC4 and C8 couple the outputs of the amplifier to the speakers. C9 and C10 are noise filtering capacitors. C1 and C5 are bootstrap capacitors for the left and right channels.
[read here...]