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Old 10th October 2012, 07:56 AM   #5461
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Quote:
Originally Posted by Salas View Post
Great. Zobel is 'not' optimized, or is 'now' optimized?

P.S. Is there a Z Foil resistor in the picture between trimmer and a BJTs pair?
Hi, Salas.
1)NOT optimized. Next step I will try. Or will anyone try?
2)Yes.

Best regard
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Old 10th October 2012, 07:59 AM   #5462
Salas is offline Salas  Greece
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Quote:
Originally Posted by Phisci View Post
Excellent, thanks,
Forgot 1 more: Total CCS should be equal to at least 150mA + load current?
The hotter the better but troublesome for sinking and for hitting 9610's limit eventually, so yes 150mA extra is logically good. Nothing stops you to run say 250mA extra if its a 9V reg for a 50mA load so the heat is still manageable of course.
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Old 10th October 2012, 08:04 AM   #5463
Phisci is offline Phisci  South Africa
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Why does Kazuo get better results with a STP55NF06L? What changes in going from 640? What alternatives would you suggest to STP55NF06L if not available?
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Old 10th October 2012, 08:06 AM   #5464
Salas is offline Salas  Greece
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Quote:
Originally Posted by Kazuo Ozawa View Post
Hi, Salas.
1)NOT optimized. Next step I will try. Or will anyone try?
2)Yes.

Best regard
Now I see, you mean you want to still investigate about the Zobel and sonics regarding the new ST MOSFET. Now values come from the high capacitance Renesas we tried to get better before.

Since you got the nice 200 MHz Tek scope just watch that the now firm stability is not compromised during tuning it.
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Old 10th October 2012, 08:08 AM   #5465
Salas is offline Salas  Greece
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Quote:
Originally Posted by Phisci View Post
Why does Kazuo get better results with a STP55NF06L? What changes in going from 640? What alternatives would you suggest to STP55NF06L if not available?
Kazuo is trying below 5V and he had to find an optimal low Vgs threshold Mosfet. He got a little unlucky with the first one, a Renesas. 640 is fine for the normal reg.
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Old 10th October 2012, 08:18 AM   #5466
Salas is offline Salas  Greece
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P.S. I will have to wrap up the REFLEKTOR in a short pdf guide soon I guess, since enough seem to try it by now.
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Old 10th October 2012, 08:22 AM   #5467
Phisci is offline Phisci  South Africa
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Sorry for the ignorance, but how does Iref relate to Total I or Load I or Shunt I in Vout=(Iref*R6)+(2Vbe+VfD1) and as importantly, how does that all relate to Vgs for IRF640?

And also, does your guide of Min(Vo-Vi)>=5V still hold?
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Old 10th October 2012, 08:32 AM   #5468
Salas is offline Salas  Greece
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As the 640 biases open its Vgs is about 4V. That one is a steady parameter in the circuit. It creates 4mA current through the 1K left side load resistor. This current is auto matched to the right side of the mirror and creates the reference voltage for the system by I/V transformation on the trimmer, adding the LED drop and two transistors drop of that side also.

Yes, the 5V minimum drop across the regulator recommendation has never changed.
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Old 10th October 2012, 08:41 AM   #5469
Phisci is offline Phisci  South Africa
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That's great Salas! I may actually be starting to understand some of the ways in which the reflektor works through your kind efforts!

Vout=(Iref*R6)+(2Vbe+VfD1), where Iref = Vgs/(left side load reflektor). For IRF640, Vgs= 4V
R6 is the pot;
Vbe is for 2N4403
VFD1 is for diode in mirror

1. Total CCS current is (2N4403)Vbe/R1 = load current plus shunt current = load current plus ca 150mA as a guide
2. Absolute value of Min (Vout-Vin) >=5V
3. The dissipation on 9610 mosfet is (Vin-Vout)*(CCS current)
4. The dissipation on 640 mosfet is (Vout)*(CCS current-Load current)
5. Adjusting the Reflektor for different optimal currents, the best way would be to change R1

Last edited by Phisci; 10th October 2012 at 08:46 AM.
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Old 10th October 2012, 08:47 AM   #5470
Salas is offline Salas  Greece
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In very simple circuits the loops and sources are not relegated to specialized sub circuits that are obvious in the drawings, and it can be puzzling.
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