Sundown Salt 500.4 power supply driver transistors

[chipper]

Anyone have a cross reference for these? Saw original power supply devices were 3205. Can I use the same mosfet with 47 ohm gate resistors?

 

[Perry Babin]

Mouser has them.

I don't think I understand the other question. The 3205 and 47 ohm gate resistors are commonly used together.

 

[chipper]

Yes that’s what I was asking sorry about that. Do you happen to have a number I can look up on mouser?

 

[Perry Babin]

755-2SB1260T100R

 

[chipper]

Thanks. Is there a npn part number as well?

 

[Perry Babin]

755-2SD1898T100P

 

[chipper]

Do you know which location is pnp / npn? Also having a hard time locating pin connections for Q31

 

[Perry Babin]

The connections are essentially the same as in the diagram below. All collectors go to ground. All bases go to the TL494, either pin 9 or 10. The emitters go to the gate resistors for the 4 banks of PS FETs.

 

[chipper]

And what is that small diode for I see one that appears to be connected to base & emitter pins if I’m correct. q31 base & collector pins came off so I’m kinda confused as where or what they were connected to originally

 

[Perry Babin]

All 4 of these circuits are copy and paste. Use one of the others for a reference.

The diode passes voltage from the 494 to the gate resistors when the output from pins 9/10 is high (near 12v). Sometimes an NPN transistor is used. Either will work. This is what they chose to use.

The PNP transistor is used to pull the gate drive voltage back to ground when pins 9/10 go back to ground.