SSLV1.1 builds & fairytales - Page 22

merlin el mago · 02:22 PM

With first +- regs I reached +-24Vout very easily but the second +- regs the posistive rail I get max +24Vout with trimmer at each max position & after warm up, negative rail only I get max -23.6Vout with trimmer at max. position, I'm using in all regs:

Tx 24VAC - 0 - 24VAC 120VA so 60Va per winding
PSU 10.000uF 63VDC Jensen 4 pole caps
Vin at the reg -33,7VDC
Load 1K 5W
R1 3R9 1.5V across (384mA)
I used two differents Tx with the same results

I don't understand the reason because first +- reg was operating OK without any problem at first attempt

Tea-Bag · 13th August 2011, 02:44 PM

Quote:

Originally Posted by merlin el mago

With first +- regs I reached +-24Vout very easily but the second +- regs the posistive rail I get max +24Vout with trimmer at each max position & after warm up, negative rail only I get max -23.6Vout with trimmer at max. position, I'm using in all regs:

Tx 24VAC - 0 - 24VAC 120VA so 60Va per winding
PSU 10.000uF 63VDC Jensen 4 pole caps
Vin at the reg -33,7VDC
Load 1K 5W
R1 3R9 1.5V across (384mA)
I used two differents Tx with the same results

I don't understand the reason because first +- reg was operating OK without any problem at first attempt

Add a resistor into diode position, or swap out the R203 for something larger.

Salas · 13th August 2011, 02:56 PM

Quote:

Originally Posted by merlin el mago

I don't understand the reason

The reason is something's smaller in the reg that can't go 24V. If the resistors are the same, then simply the K117 in the lower Vo reg has less Idss than in the other reg. Add more resistance as Tea wrote. Simple Ohm's law.

merlin el mago · 03:06 PM

I believe the suggested resistor value is 1K or less, right?

Salas · 13th August 2011, 03:04 PM

Quote:

Originally Posted by necplusultra

gave it a dummy R load when I fired it up. using 10R at 301

turning the trimmer does not change the V either.

using a 18V AC tfo

Check that your Q103,203,303 are K117 JFETs and not BC transistors by mistake. Because one reason can be having no current to drive the V reference resistors and trimmers. What dummy value?

Salas · 13th August 2011, 03:05 PM

Quote:

Originally Posted by merlin el mago

Suggested resistor value?

What resistor and trimmer you use now in the -23.6V max one?

Salas · 13th August 2011, 03:26 PM

Quote:

Originally Posted by merlin el mago

I believe the suggested resistor value is 1K or less, right?

Tell me what you use now first, so I can calculate your current.

merlin el mago · 13th August 2011, 03:36 PM

All-Fet Line Amplifier EB-1198/16/116 & All-Fet I/V Converter and Filter for DACs EB-201/214/DAC13, don't worry I have the Erno Borbely manuals so I change the load resistor for the needed 270R 5W recommende for Erno.

Salas · 13th August 2011, 03:41 PM

I am repeating the question in a graphical manner.

merlin el mago · 03:58 PM

10-25Vout R303 1.8Kohm 5K trimmer as per your guide

13th August 2011, 03:02 PM	#214
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	I believe the suggested resistor value is 1K or less, right? Last edited by merlin el mago; 13th August 2011 at 03:06 PM.

13th August 2011, 03:55 PM	#220
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	10-25Vout R303 1.8Kohm 5K trimmer as per your guide Last edited by merlin el mago; 13th August 2011 at 03:58 PM.

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13th August 2011, 03:36 PM	#218
merlin el mago diyAudio Member Join Date: Sep 2009 Location: Catalonia new Europe state	All-Fet Line Amplifier EB-1198/16/116 & All-Fet I/V Converter and Filter for DACs EB-201/214/DAC13, don't worry I have the Erno Borbely manuals so I change the load resistor for the needed 270R 5W recommende for Erno.