SBG-PID

[Altra]

Q3 is the series pass negative regulator. In the sim it looks like it is shorted between the collector of Q3 and sw1. The emiter and collector of Q3 are reversed also. Probably other errors

[aft_72005]

Everything between C1 and R20,R23... doesn't make any sense.

Yes, I drew the power section according to Sascho's SBG circuit diagram .

[aft_72005]

Q3 is the series pass negative regulator. In the sim it looks like it is shorted between the collector of Q3 and sw1. The emiter and collector of Q3 are reversed also. Probably other errors

see this transistor VT9 is not series .

[aft_72005]

but simulation is ok .. out put is +6V and -6V !!!!

[aft_72005]

[ATTACH]57258[/ATTACH]

also your power section drew ........simulation is OK .

[Altra]

see this transistor VT9 is not series .

VT 9 is in series. The negative 12v goes through D1 and then VT 9 to v-. The feedback to the base of VT 9 controls the voltage to v- . Judging by the 4.7 v zener, the output should be about -10v and split supply +/-5v.

[aft_72005]

Q3 is the series pass negative regulator. In the sim it looks like it is shorted between the collector of Q3 and sw1. The emiter and collector of Q3 are reversed also. Probably other errors

but with this configuration .. out pout drop to 4.7V+...4.7V-

[Altra]

That looks more correct than the first sim. It will work fine on -9.4V.

Add try reversing VT 9 /Q3 collector and emitter and see what output voltage you get.

[aft_72005]

That looks more correct than the first sim. It will work fine on -9.4V.

Add try reversing VT 9 /Q3 collector and emitter and see what output voltage you get.

did this test out put drop to 3.18V+...3.8V - . this configuration not correct .

[Carl-NC]

but with this configuration .. out pout drop to 4.7V+...4.7V-

Yes, this is correct.

Add try reversing VT 9 /Q3 collector and emitter and see what output voltage you get.

That's not correct, and the original SBG schematic appears to have VT9 backwards. It will still work (sort of), but the beta will be about 2 instead of 100+.

[dbanner]

This works, note orientation of Q3.

[dbanner]

THIS WORKS.

[aft_72005]

THIS WORKS.

but with this configuration Q3 bias is reverse

[Altra]

Dbanner is v1 in your sim -9v or -12v? It should -12 and regulated between -9 to 10v on the negative rail.

[dbanner]

You're right. I'm having a closer look at the schematic.