Jim hi,
Check the BC transistors and the LEDs with the DMM's diode mode. Without removing them.
Check the BC transistors and the LEDs with the DMM's diode mode. Without removing them.
Hi Salas -
DMM = UNI-T UTI39C Diode mode
BC transistors on negative reg:
Q1 B:E 0.059 B:C 0.559 / reversed leads B:E 0,059, B:C 0.597
Q2 B:E 0.266 B:C 0.634 / reversed leads B:E 0.266 B:C OL
Q3 B:E 0.691 B:C 0.634 / reversed leads B:E OL B:C 1.134
Q4 B:E 0.323 B:C 0.591 / reversed leads B:E 0.396 B:C 1.022
Continuity between E:C, checked out, no shorts on all 4 BC transistors
Measurements made w/ M2 installed, M1 is out of circuit at the moment.
LED's tested correctly.
Thanks again,
Jim
DMM = UNI-T UTI39C Diode mode
BC transistors on negative reg:
Q1 B:E 0.059 B:C 0.559 / reversed leads B:E 0,059, B:C 0.597
Q2 B:E 0.266 B:C 0.634 / reversed leads B:E 0.266 B:C OL
Q3 B:E 0.691 B:C 0.634 / reversed leads B:E OL B:C 1.134
Q4 B:E 0.323 B:C 0.591 / reversed leads B:E 0.396 B:C 1.022
Continuity between E:C, checked out, no shorts on all 4 BC transistors
Measurements made w/ M2 installed, M1 is out of circuit at the moment.
LED's tested correctly.
Thanks again,
Jim
LEDS check, OK.
Those are all NPN transistors. The red probe was always on B pin (as it should) when you measured the junctions against C, E, pins?
Those are all NPN transistors. The red probe was always on B pin (as it should) when you measured the junctions against C, E, pins?
Re-measured post video, changed to Extech DMM:
Q1 B:E .020, B:C .541
Q2 B:E .096, B:C .578
Q3 B:E .580 B:C .610
Q4 B:E .543 B:C .122
Double checked I got it right. What say you as to what to replace?
Q1 B:E .020, B:C .541
Q2 B:E .096, B:C .578
Q3 B:E .580 B:C .610
Q4 B:E .543 B:C .122
Double checked I got it right. What say you as to what to replace?
I changed out Q1 and Q2. Re-powered briefly. No light from LEDs and R1 immediately hot with a wisp of smoke, same fault as prior.
Thank you, Salas. I took at close look relative to the schematic per your advice. The offending negative rail M1 = FQP 3P20. Schematic calls for FQP 3N30.
M2 has IRF530. Schematic calls for IRF9530
On my 5VDC working UB, M1 if FQP 3N30. M2 neg rail has IRF9530. And the other TB supply kits on the neg side have those, too.
Could this be the cause of the fault?
M2 has IRF530. Schematic calls for IRF9530
On my 5VDC working UB, M1 if FQP 3N30. M2 neg rail has IRF9530. And the other TB supply kits on the neg side have those, too.
Could this be the cause of the fault?
After the tests carried out M1 defective but Q2, ok, do I have to check something else?
On the other hand, I don't know how I'm going to get this FQP3N30, what equivalent can I have? Or, if someone has one who can sell it to me, I'm a taker.
Hi, IRF610PBF should substitute FQP3N30. The LEDs or M2 or JFETs are seldomly reported broken, but you can check.
Hi Salas, I am considering to use dual mono UbiB for DCG3. For DCG3 I use R10 - 7R5 (150mA). Which R1 to choose in uBiB for DC+ and DC-?
How big heatsink does M1 + M2 need at this current? Rth: ?°C/W
Thank You!
How big heatsink does M1 + M2 need at this current? Rth: ?°C/W
Thank You!
The easiest way to attach ultracaps to the UltraBiB would be to precharge the ultracaps to same level as UltraBiB output voltage. Then you can safely connect.
If using this method take into account the fact that if you turn off your UltraBiB the DAC will still be powered by the ultracaps until they discharge.
On another topic, I was already using 2 x UltraBiB set to 16.5v to power some TWTMC-DRIXO clocks for a while, but never had the chance to do a comparison between UltraBiB and something else. Until last night when I configured a 8v UltraBiB for the analog stage of my DAC.
Mind you, I'm using 20 PCM1794A chips so I used a 0.5R CCS resistor for 1.2A output and a big radiator.
Comparison was done between UltraBib and 2x 150Ah Li-Ion cells connected in parallel with 4x 3000F ultracaps. Precision wise the battery+UC combo wins, but the UltraBiB has a sweet and musical sound rendering a nice atmosphere. Decay is on another level on the UltraBiB. And this is without Quasimodo snubber (yet).
Might also try to put the 4x 3000F ultracaps in parallel with the UltraBiB output to see what changes/improves.
Thank you Salas for this wonderful device!
Just a brief follow up with gratitude to you, Salas. Success in getting the 12V BiB running. Proceeded to #3 which is intended 30V to power D1 I/V. I learned tons about diagnostics, having symptoms of another overheated R1. Running through all the checks and diode mode measurements, wrongly concluded M1/M2 were bad as they measured funny in situ. Once extracted, I re-measured and wouldn't you know they were not broken. Close inspection revealed I had a short between R4 and R8. Once corrected, it's working. Will report again once I get the DAC running.