QUASI Amplifier for Beginners


Hi
This protection with the values ​​of components for power supply Us = + /-70Vdc!;)
Please give the values ​​of components of protection for the power supply Us = + /-45Vdc?:rolleyes:
Thanks
P.S.
Please give a equations to calculate the resistor value of this protection?
 
Last edited:
Hi Mile (Apex)!
I made this your amplifier, with power supply Ucc= + /-68Vcd (2x50Vac), and with the output transistors 8xMJ15003!
When i let the amplifier somewhere with 50% power, after 2 ... 3 hours of work output transistors burn!?
With the diodes D3 and D4 impossible to regulate the bias.
So I made ​​some changes with the transistor - see schematic (Figure 1)
Question: Is this a good solution to the transistor, if not please suggest some other more secure!
thanks and cheers !

P.S.
Zdravo Mile!
Posto slabo mi ide engleski (vidis i sam), dali moze da se obratim na srpski na tvoj E-mail?
Pozdrav
 

Attachments

  • Figure 1 (550W).pdf
    66.7 KB · Views: 520
You need separate emitter resistors for each output transistor.
They should be a higher value, but can probably be lower power. Maybe 1 ohm, 2 watts each.
 

Attachments

  • sch.GIF
    sch.GIF
    28 KB · Views: 1,162
Last edited:
What you search it's right here.....

Hi radio ,
I have search for you an better schematic , also tested one . I have done small changes for 2SC 5200 as finals .....:) I hope you like it .
Regards Alex.
 

Attachments

  • Nbip300schematic.pdf.pdf
    42.1 KB · Views: 708
  • QUASI 300 BJT N PCB TOP ALL.pdf
    151.8 KB · Views: 690
  • QUASI 300 BJT N PCB TOP VIEW.pdf
    46.5 KB · Views: 578
  • QUASI 300 BJT N.jpg
    QUASI 300 BJT N.jpg
    789.1 KB · Views: 1,217