60 Watts Amplifier

[elmertronics]

totoo ba yan 18v 500mA 

iyan lang kasi ang supply ko dito

[Johannah Aleksandria]

sinubukan ko lang kanina sa 18V 500mA na supply. .tapos 4ohms na 275W ang max power. .ok ang output nya kaso pag full ko na ang pot medyo basag na. .

Tama pala yung circuit mo, common-emitter nga yung C945, gain nya ay galing sa 100k(feedback).

[tony]

sinubukan ko lang kanina sa 18V 500mA na supply. .tapos 4ohms na 275W ang max power. .ok ang output nya kaso pag full ko na ang pot medyo basag na. .

hindi 60 watts, baka 6 watts lang..

[tony]

masyadong transistor dependent yung circuit mo.....dapat aregluhin para mapatunog ng maayos...

[Johannah Aleksandria]

Dapat yung feedback tlaga nito galing sa output tranny o kaya gawin na lang Class A yung output.

[elmertronics]

hindi 60 watts, baka 6 watts lang..

hindi naman siya 6 watts. .malakas naman po ang tunog niya. .

[elmertronics]

masyadong transistor dependent yung circuit mo.....dapat aregluhin para mapatunog ng maayos...

paano po sir tony?. .

[ultrasonic™]

pa subs

[tony]

hindi naman siya 6 watts. .malakas naman po ang tunog niya. .

kumbinsihin mo ko na hindi 6watts yung amp mo.....18volts at 0.5amps ilang watts yan?

[elmertronics]

kumbinsihin mo ko na hindi 6watts yung amp mo.....18volts at 0.5amps ilang watts yan?

ay. .yan lang kasi ang available ko na supply sir tony. .try ko lang sa mataas na supply. .

[jiggins20]

working po ba talaga ang circuit nito sir?

[elmertronics]

working po ba talaga ang circuit nito sir?

working po yan. .

[tony]

ala tsamba ang circuit na to....

[elmertronics]

ala tsamba ang circuit na to....

haha di ko nga alam sir kung saan to kinuha ng nagconduct ng workshop namin. .

[tony]

^this is not the right way to learn circuits....

[TinTopHack]

mga master ito po pala ang circuit. .nagkamali lang ako sa paggawa ng diagram. .

This amp is designed to drive audio alarms. Not for listening pleasure. Most probable source of audio signal is a 555 circuit oscillator or variations of that to produce a distinct alarm sound.
 
A simple way of looking at it is -
Q3 is a collector biased common emitter stage. Its collector voltage at zero input signal sets the operating point. The voltage therefore at the emitter of Q1 and Q2 is just one Vbe higher than Q3's collector voltage.   We cannot expect the voltage at the the emitter of Q1 and Q2 to be exactly 1/2 the supply rail. It will be +/- 1 Volt (or more) around that figure because the collector voltage of Q3 will depend primarily on the temperature and Q3's hfe. For this circuit, Q1 and Q2 remains off when there is no input signal due to the single diode D1. So the biasing of Q3 and the load formed by D1 and R2 determines the collector voltage of Q3. This simplicity in this setup also allows it to operate over a wide range of supply rail voltage. Typically the supply will be 24V in industrial applications.

Q1 is a follower for the upper half of the signal while Q2 is a follower for the lower half.
Q1 and Q2 operate in class B mode due to the single diode D1 that prevents them from conducting at the same time.

[j a y k e z]

nice explanation sir TTH pogi point for you 

This amp is designed to drive audio alarms. Not for listening pleasure. Most probable source of audio signal is a 555 circuit oscillator or variations of that to produce a distinct alarm sound.

parang may nabasa akong ganito sa EE book.