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Test Equipment / Re: TinySA Ultra launched
« Last post by KungFuJosh on Today at 02:57:37 am »bug, a glitch, or a feature?
Recent Posts
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Projects, Designs, and Technical Stuff / Re: 3D printing company similar to PCBWAY for circuit board
« Last post by TERRA Operative on Today at 02:57:32 am »I've had a number of things 3D printed in resin by PCBWay, really happy with the results and price, I don't even bother 3D printing stuff myself now.
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Beginners / Re: Why are thermal jumpers so expensive?
« Last post by coppercone2 on Today at 02:55:12 am »strips are better but its still a tiny thin part for making in a chemical pressure mold
also with heaters something that raises cost alot is temperature. The cost sky rockets over ~1400C (as soon as you go more then nichrome and kanthal give)
then you start having ceramic heating elements. and then you need to control offgassing from heaters too, and it actually needs power electronics. its not in the same league as cheap stuff like porcelain (still expensive for quality). Geometrically stable chemically inert mold at 1500C. I wonder how long those last.
I think alumina you can press then heat. which makes it much cheaper, since you are not baking it under pressure
also, AlN comes in a bunch of different grades. the ones with the best thermal conductivity probobly are the worst processes. IIRC the performance of the cheap one is very poor for thermal conductivity, if you are after those 'nice' numbers
also with heaters something that raises cost alot is temperature. The cost sky rockets over ~1400C (as soon as you go more then nichrome and kanthal give)
then you start having ceramic heating elements. and then you need to control offgassing from heaters too, and it actually needs power electronics. its not in the same league as cheap stuff like porcelain (still expensive for quality). Geometrically stable chemically inert mold at 1500C. I wonder how long those last.
I think alumina you can press then heat. which makes it much cheaper, since you are not baking it under pressure
also, AlN comes in a bunch of different grades. the ones with the best thermal conductivity probobly are the worst processes. IIRC the performance of the cheap one is very poor for thermal conductivity, if you are after those 'nice' numbers
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Repair / Re: Mig welder wire feeder controller board not working
« Last post by TERRA Operative on Today at 02:53:21 am »What is the brand and model number of the welder and feeder?
I see Cigweld on the PCB, so I miigghhttt have a manual or even service manual for it.
I see Cigweld on the PCB, so I miigghhttt have a manual or even service manual for it.
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Beginners / Re: Jutter calculation ?
« Last post by ataradov on Today at 02:51:17 am »You are triggering on the rising edge, but measuring the falling edge. This is not a meaningful measurement for the typical clock application. You need to measure edge to edge. Then the measured value would be the period jitter.
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Repair / Re: Mig welder wire feeder controller board not working
« Last post by xavier60 on Today at 02:50:10 am »What feeds the PCB transformer?
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Repair / Re: Mig welder wire feeder controller board not working
« Last post by xavier60 on Today at 02:41:50 am »Where was the 24VAC measured? There appears to be a PCB mounted control transformers supplying multiple regulators.
EDIT: Does the trigger switch have proper connection to the PCB?
EDIT: Does the trigger switch have proper connection to the PCB?
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Repair / Re: Mig welder wire feeder controller board not working
« Last post by floobydust on Today at 02:33:55 am »Quick eyeball check - the relay has one set of contacts that look destroyed. The power transistor bottom left looks like it's run hot a lot, poor heat transfer to the heatsink.
A real mix of brands of electrolytic capacitors, I would replace the cheap ones. 1999 was a while ago.
A real mix of brands of electrolytic capacitors, I would replace the cheap ones. 1999 was a while ago.
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Thermal Imaging / Re: Looking for a new lens
« Last post by Hazel on Today at 02:28:40 am »Hi,Did you find the lens you needed?
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Beginners / Re: Question about use of Differential using scope USB port
« Last post by RJSV on Today at 02:26:31 am » It's a good question, when caring about safety, but maybe too general. Perhaps focus on one thing and associated question, rather than a vague, general 'things that were discussed'.
Grounding ties, and related safety should be specific to one instance, (and I don't claim to have that comprehensive).
Certainly a 'one handed' rule should specify maybe a rubber mat / shoes also, while explaining the ground paths that are to be avoided...Metal shop chair ? Ditto, as something like metal chair, with rubber feet, and in a mat, could be, cautiously, tolerated.
See how detailed and specific that was ?
But I'm not expert. Perhaps there is (or should be) a National Electrical Code unit, in D.C. that could answer / respond to the subject on Oscilloscope grounds and related recommended practice(s).
Wouldn't be surprised, if (any) agency would be 20 years behind the times, but that's normal in large agencies.
Grounding ties, and related safety should be specific to one instance, (and I don't claim to have that comprehensive).
Certainly a 'one handed' rule should specify maybe a rubber mat / shoes also, while explaining the ground paths that are to be avoided...Metal shop chair ? Ditto, as something like metal chair, with rubber feet, and in a mat, could be, cautiously, tolerated.
See how detailed and specific that was ?
But I'm not expert. Perhaps there is (or should be) a National Electrical Code unit, in D.C. that could answer / respond to the subject on Oscilloscope grounds and related recommended practice(s).
Wouldn't be surprised, if (any) agency would be 20 years behind the times, but that's normal in large agencies.