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News:
I have moved the forum to an another web hotel and at the same time done some housekeeping. All zero-posters are removed. Feel free to register again.
Cheers
Per-Anders Sjöström
Recent Posts
22
Power supplies / Re: Large voltage drop SPS01
« Last post by peranders on February 03, 2013, 06:37:59 PM »You mean instead of 2 x 24 VAC you had only 1 x 24 VDC?
Good to hear it's working.
Good to hear it's working.
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Power amplifiers / Re: Help needed to debug QRP-02
« Last post by peranders on February 02, 2013, 08:25:09 AM »It's hard to tell where the problem is just by doing resistance measurements. Which tracks got burnt? Could you find a regulated power supply?
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Power amplifiers / Re: Help needed to debug QRP-02
« Last post by jamh on February 02, 2013, 02:27:14 AM »So I got a 38V transformer and the results were not so good. Two of the PCB traces got smokey and I shut it down quickly. Prior to that I looked carefully at all the solder joints. Not much wrong anywhere that I could see.
I'm not too hopeful we can debug this, nevertheless I took some resistance measurements from some of the PCB points (vs GND) and thought maybe something can be learned from them. There were 21 little spots on the PCBs that I could measure. Since they're not labeled, this is the best way I thought of reporting them:
http://i.imgur.com/X87JpE3.jpg
Maybe something will jump at you. If not, that's ok, perhaps, like I said, I can use them as regulated power supplies.
I'm not too hopeful we can debug this, nevertheless I took some resistance measurements from some of the PCB points (vs GND) and thought maybe something can be learned from them. There were 21 little spots on the PCBs that I could measure. Since they're not labeled, this is the best way I thought of reporting them:
http://i.imgur.com/X87JpE3.jpg
Maybe something will jump at you. If not, that's ok, perhaps, like I said, I can use them as regulated power supplies.
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Power amplifiers / Re: Help needed to debug QRP-02
« Last post by jamh on January 30, 2013, 07:36:43 AM »Working on it. Will let you know.
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Power supplies / Re: Large voltage drop SPS01
« Last post by Sjoerd Smits on January 27, 2013, 03:10:38 PM »Hi PA,
Found the problem.... It was X3 and X4... I had nothing there.... so that was the problem!
Thanks!
Regards,
Sjoerd
Found the problem.... It was X3 and X4... I had nothing there.... so that was the problem!
Thanks!
Regards,
Sjoerd
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Power supplies / Re: Large voltage drop SPS01
« Last post by peranders on January 27, 2013, 02:57:02 PM »Are X3 and X4 shorted or do you have a resistor there?
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Power supplies / Large voltage drop SPS01
« Last post by Sjoerd Smits on January 27, 2013, 11:48:48 AM »Hi PA,
I get a really large voltage drop when I connect the amps to the SPS01 power supply. NEG-Ground = -17VDC and POS-GROUND= 22VDC
Unloaded the voltages are 33VCD.
I have a toroid from Amplimo whitch provides 2 x 25VAC at 10 Amps.
I purchased the rectifiers directly from you. You provided me with 8x MOSPEC U30D20 rectifiers. The datasheet of these rectifiers state that the operating voltage should be between 50 and 200V.
So I see 2 strange things:
1: It takes upto 3 minutes for the SPS01 to go from 0 to 33VDC.
2: When load is applied, the voltages drop dramaticly to 17 and 22 VDC.
Question: What could be the problem?
Kind regards,
Sjoerd Smits
I get a really large voltage drop when I connect the amps to the SPS01 power supply. NEG-Ground = -17VDC and POS-GROUND= 22VDC
Unloaded the voltages are 33VCD.
I have a toroid from Amplimo whitch provides 2 x 25VAC at 10 Amps.
I purchased the rectifiers directly from you. You provided me with 8x MOSPEC U30D20 rectifiers. The datasheet of these rectifiers state that the operating voltage should be between 50 and 200V.
So I see 2 strange things:
1: It takes upto 3 minutes for the SPS01 to go from 0 to 33VDC.
2: When load is applied, the voltages drop dramaticly to 17 and 22 VDC.
Question: What could be the problem?
Kind regards,
Sjoerd Smits
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Power amplifiers / Re: Help needed to debug QRP-02
« Last post by peranders on January 26, 2013, 10:21:02 AM »Can't you borrow a regulated power supply, 2 x 30 V or so? You'll need only 200-300 mA.
To start with you buffer should have 1-2 mV out.
To start with you buffer should have 1-2 mV out.
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Power amplifiers / Re: Help needed to debug QRP-02
« Last post by jamh on January 26, 2013, 01:14:00 AM »Well I don't remember if I tested them back then or not, but they've never been used before. I could get a tranny, but I was hoping I could identify with lower voltages what's shorting or what's blown, something like measure the voltage at point x, and it should be vv, and at y should be v, etc.. If they're blown, I didn't want to spend money on an expensive tranny.