Saturday, April 13, 2013 0 comments
As we are like to indicate you about audio and sound circuit ,I found the circuit which is just right one for energy amplifier with one MOSFET.
The output power of an operational amplifier is regularly elevated by way of a complementary emiter follower.
It can be carried out with a MOSFET,but it's not a excellent suggestion to join the type of instrument as a complementary souce follower because the maximum output voltage of the opamp is then decreased extensively by way of the gate-source keep a watch on voltage of the MOSFET ,which can be a few volts.
Another method is to join two MOSFETs as a complementary drain follower.The (alternating) output current provided by using the MOSFETs is limited by way of the stage of the provision voltages and the saturateion voltages of T3 and T4 Resistor R8,together with R9,provides comments for each the opamp and MOSFETs .
The open-loop amplification of the opampis,therefore,increased via (1+R8/R9).the closed-loop amplification of the entire amplifier is (1+R3/R2).
The present source shaped by using T1 and T2 is required for arreanging the quiescent present of T3 and T4 at 50 mA.The values of resistors R4 and R5 are such that,without the present supply the voltage drop throughout the resistor because of the direct present in the route of the opamp is not enough to change on T3 and T4 .with the present supply,and depending on the surroundings of P1,the voltages across R4 and R5 upward push,which increases the quiescent present by means of T3 and T4.
In view of the temperature dependence of the quiescent present,T2 must be hooked up on the popular heat sink(c. 5 K/W) of the MOSFETs.
The output power shouldn't be less than 20 W into 8 ohm,at which level the harmonic distortion quantitys to zero.075 per cent at one hundred Hz to zero,135 per cent at 10 kHz.