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Old 20th November 2012, 03:56 PM   #8571
Salas is online now Salas  Greece
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Quote:
Originally Posted by Doug R View Post
Vdrop at R1 did not change appreciably. Still about 1.5 V.
After restored glowing leds I had in mind.
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Old 20th November 2012, 03:59 PM   #8572
Salas is online now Salas  Greece
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*What kind of scope? How fast probes it needs?
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Old 20th November 2012, 05:15 PM   #8573
Doug R is offline Doug R  United States
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OK, had a bad thing happened. Reg slipped out of my hand and landed hard on the concrete, due to the weight of the heatsinks. Broke the perfboard, but I think it will be OK after some Crazy glue.

All three LEDs light up, and it is probably regulating, as they go out if I touch the R1 to read voltage, and then come back on after a second.

R1 seems VERY sensitive to current drawn. 10 ohms gave over 200 mA, spliced in a 1 ohm and then another 0.5 ohm, and am down to 188 mA (2.2 V/11.7 ohm)

So I will need to play around with that, and glue the board back together and clean up some messy work. Starting to look like a dead bug project.

I think its OK though. Will report back later or tomorrow.

Gracia Mr Salas!

Doug
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Old 20th November 2012, 06:22 PM   #8574
RCruz is offline RCruz  Switzerland
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Quote:
Originally Posted by Doug R View Post
OK, had a bad thing happened. Reg slipped out of my hand and landed hard on the concrete, due to the weight of the heatsinks.

Starting to look like a dead bug project.
Hi Doug

Unfortunate things happen.... Never mind.... It will be a blast in the end
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Old 21st November 2012, 02:45 PM   #8575
Doug R is offline Doug R  United States
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Here's an update:

I epoxied the board, and it is good enough.
Adjusted R1 to 15 ohms, got 150 mA with 39 V in, 28 V out.
Kept burning out the amber LEDs if my probe slipped while reading volts.

I thought maybe the red ones I have would be more reliable, so I put them in.
This changed the Vdrop from 1.7 V per amber LED to 1.5 V per red LED.
This changed the current to about 100 mA, so I need to go change R1 again.

Anyway, the LEDs are glowing and I think it will be OK after I lower R1 a bit.

Really appreciate all the support!

Doug
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Old 21st November 2012, 02:46 PM   #8576
Doug R is offline Doug R  United States
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Salas, the scope is 30 Mhz B & K.
I just got it last week and haven't ordered the probes yet.
I'll just get something off of eBay probably.

Doug
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Old 21st November 2012, 04:06 PM   #8577
Salas is online now Salas  Greece
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Yes, those on Ebay that get advertized as 100MHZ are sufficient for your scope. Always remember that probes are nominally voltage rated at x10, and they lose much of that spec with frequency and/or x1. So make sure you will read their little leaflet. They also lose a drastic amount of bandwidth at x1 due to no self capacitance division. That voltage spec thing I remind you given the opportunity because you are a tubes builder and there will be HV. There is a US company named Cal Test Electronics that has a most thorough line of probing, clipping, connecting, everything in logical prices by the way. Maybe their spec would be more reliable despite of where they possibly OEM.

As for led colors and voltages and CCS current affected report, it all looks like going by the book. Photo time!
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Old 21st November 2012, 04:39 PM   #8578
Doug R is offline Doug R  United States
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Salas,
Reduced R1 to 9.6 ohm; got 150 mA. Looks good. WIll get a photo in a bit.

Do these probe look OK?

Scope Probe Set with Isolated BNC | 100MHz | Selectable x1/x10
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Old 21st November 2012, 05:04 PM   #8579
Salas is online now Salas  Greece
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This probe looks like the one in Rigol 1000 series, should be honest spec wise. Small and agile.
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Old 22nd November 2012, 03:23 PM   #8580
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Exclamation Cowboy Legs & Ammo Belts !!! ( mean lookin' hombres ! )

50 mean as hell, gunslingin' cowboys from the 'Toshiba Ranch' arrived today.

This time 'Zhoufang' stylee ( the Singapore-Sling ! )...BOO JAH !

That enough bad-boy bandido's, to start a revolution !...
...or even 33 & a 1/3rd of them !

Now we rockin' phono-freaks !

I'm outta here...
...where's that meter ?

Cheers.


Si.
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