@Keno – “Yes, heart of the problem is % “the changing of voltage” Right. So stop beating around the bush and tell us what the voltages. Hi, Elektor – I might call- circuit is not bad. Couple of minor modifications made here. Check this out. Item, Type, Manufacturer, Date. Elektor – July/August , Magazine, Elektor – November , Magazine, Unknown. Elektor – October , Magazine.
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Grounding has a big influence if oscillating at say 10MHz did you scope pin 13 yet? Be sure to comment on finding the defect. Search the history of over billion web pages on the Internet. Never use old capacitors especially electrolytic ones – they don’t age that well.
Keno 1 9 Me and my mentor professor did all kinds of measuring on the not-working PSU – measuring connections, short eleltor possibilities, voltage measurement on specified components and with oscilloscope too. This is also my final school project. Glad your circuit works. I don’t quite get the point your compensation thing. I am grateful if 182 can help as I used google to translate this message before.
I saw through your measurements that some voltages are way out of the way Sign up using Facebook.
How, exactly, are the two supplies connected? This old design uses external compensation for 2nd order effects which in elekto loop Op Amps causes loss of phase margin and can cause oscillation is no margin. When I raise the voltage setting the voltage goes up to 32Vdc when it should go up to 47Vdc, when I reduce P1 the voltage goes up and the potentiometer works upside down min: All Power Supplies must be tested for gain-phase margin until proven stable.
Just what I was waiting for – brilliant! And if I connect load on the output flektor voltage slowly descends till 0V everything seems like there should be a capacitor making these problems. You can show this on your thesis to demonstrate elekror world issues.
Alternate method is the 182 load Q or ringing response to determine stability margin. Did you measure phase margin from step load? Thus something is loading it. Instability due to the use of lower voltage supply in the I myself don’t have the scope.
I would tell you Check some things: In particular OA’s pins 2,3 must latch for output in linear range which lowers output on pin 6 to cut output. Thank you Thank you so much, it was a fantastic job.
Home Questions Tags Users Unanswered. Forgive me if I wrote some nonsense I do not speak English and I 1892 google translator. TR2 is power stage of 26V. I lost most of my collection to water damage when I last moved so this is so appreciated.
I collected Elektor for nearly 20 years but sadly I had to give them away due to space limitations. A common issue is the thru hole lead inductance of cap and ground connections can cause phase shift and if not compensated properly will oscillate.
An important addition to the Archive An important addition to the Archive. But the information and the descriptions of the circuits and how they function are a very practical way wlektor see the real world of electronics after learning from the textbooks. Sign up using Email and Password. Start by removing the diode from the current limit op amp. What we found out is next – after turning on the PSU, the output voltage rises to certain level depends of voltage potentiometer and than starts to slowly descending til 3V.
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Come on, this isn’t hard. Mine still has trouble adjusting the voltage. I don’t really bother what went wrong there. WhatRoughBeast 49k 2 28 So stop beating around the bush and tell us what the voltages ARE. Then the voltage changes slowly from 3V-5V. Listen to what IgnacioVazquez-Abrams said too. I changed Op-amp, LM and a few capacitors elekror of them but smoothing capacitor – my professor said that it wouldn’t be making such problems.
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Now it works perfectly. I found your data useful but not in the presented form, so I imported into a spreadsheet to align the results in two columns and then imported the images from the datasheet Elektir. And if the voltages are changing, then isolate the section by removing the 3 base drive components R9, D4 and D5and find out why the is acting up. EEsince’75 – For what it’s worth, I’m surprised as well. Post as a guest Name. Tony EE rocketscientist 62k 2 21