DC cable puzzle

Started by Terry Pinnell in sci.electronics.basics4 weeks ago 16 replies

Tidying up my shed workshop I got an electric shock from a cable pair that had earlier been disconnected from its 14V DC power supply. So...

Tidying up my shed workshop I got an electric shock from a cable pair that had earlier been disconnected from its 14V DC power supply. So I'd expect it to have virtually zero voltage across it, apart from ac noise. Its destination is a garden lamp relay box about 80 ft away from the supply. For some of that distance it runs close to a mains cable (unloaded at the time). My DMM consistently...


Thermodynamics An Engineering Approach , By Yunus A. Cengel & Michael A. Boles & McGraw-Hill, 2011 , 7th ed

Started by Anonymous in sci.electronics.basics1 month ago

solutions book team g e t . s o l u t i o n s b o o k @ h o t m a i l . c o m get.solutionsbook(at)hotmail(dot)com...

solutions book team g e t . s o l u t i o n s b o o k @ h o t m a i l . c o m get.solutionsbook(at)hotmail(dot)com get.solutionsbook@hotmail.com We're a team for providing solution manuals to help students in their study. We sell the books in a soft copy, PDF format. We will find any book or solution manual for you. Just email us: g e t . s o l u t i o n s


The Cosmic Perspective , Bennett & Donohue & Schneider & Voit , 3rd ed

Started by Anonymous in sci.electronics.basics1 month ago

solutions book team i n e e d s o l u t i o n s b o o k @ h o t m a i l . c o m ineedsolutionsbook(at)hotmail(dot)com...

solutions book team i n e e d s o l u t i o n s b o o k @ h o t m a i l . c o m ineedsolutionsbook(at)hotmail(dot)com ineedsolutionsbook@hotmail.com We're a team for providing solution manuals to help students in their study. We sell the books in a soft copy, PDF format. We will find any book or solution manual for you. Just email us: i n e e d s o l u t i


structural analysis , By Hibbeler , 3rd ed

Started by Anonymous in sci.electronics.basics1 month ago

solutions book team i n e e d s o l u t i o n s b o o k @ h o t m a i l . c o m ineedsolutionsbook(at)hotmail(dot)com...

solutions book team i n e e d s o l u t i o n s b o o k @ h o t m a i l . c o m ineedsolutionsbook(at)hotmail(dot)com ineedsolutionsbook@hotmail.com We're a team for providing solution manuals to help students in their study. We sell the books in a soft copy, PDF format. We will find any book or solution manual for you. Just email us: i n e e d s o l u t i


MC6840 Projects????

Started by Anonymous in sci.electronics.basics1 month ago

Any suggestions for projects I could do that involves the Motorola MC6840 programmable timer module? I just received a peripheral for the Apple II...

Any suggestions for projects I could do that involves the Motorola MC6840 programmable timer module? I just received a peripheral for the Apple II that has this chip onboard. It basically allows for applications that involve timers, such as reading digital potentiometers, among other things. Thanks!


VOX- Voice operated Relay with mods.

Started by amdx in sci.electronics.basics1 month ago 2 replies

I'm starting to develop a VOX circuit to solve the following problem. Wife got new smart phone after flip phone went in water. We're on a...

I'm starting to develop a VOX circuit to solve the following problem. Wife got new smart phone after flip phone went in water. We're on a boat. Wife's phone is inside now, she's outside working, can't hear the phone ring. Won't take the phone outside, I think she thinks she paid $0.01 for the flip phone and $200 for the smart phone and won't take a chance with it. So I want to build ...


Transformerless power supply

Started by amdx in sci.electronics.basics2 months ago

Is it reasonable/possible to build an 8 amp 20 V transformerless power supply from a 120Vac line. I calculate about 180uf plus or minus...

Is it reasonable/possible to build an 8 amp 20 V transformerless power supply from a 120Vac line. I calculate about 180uf plus or minus depending on other components. Maybe 9- 20uf caps in parallel? I'd like to build it into a leaf blower. All plastic, absolutely no metal exposed. I think I've answered my question, I have 12, X rated caps in my junk box, but they are only 1uf....


Is Class 1 laser safe enough for baby eyes?

Started by Mr. Man-wai Chang in sci.electronics.basics2 months ago 11 replies

I meant, what if someone accidentally shine Class 1 laser into a baby's eyes? Would it hurt retina and leave a permanent damage? I know ......

I meant, what if someone accidentally shine Class 1 laser into a baby's eyes? Would it hurt retina and leave a permanent damage? I know ... I know... it should NOT happen. Adults are supposed to be very very careful. :) -- @~@ Remain silent! Drink, Blink, Stretch! Live long and prosper!! / v \ Simplicity is Beauty! /( _ )\ May the Force and farces be with you! ^ ^ (x8...


Formula for calculating run time of apc ?

Started by Andy in sci.electronics.basics2 months ago 3 replies

I am looking for a formula for calculating the run time of my APC battery system. I did a search but what I found required a particular model...

I am looking for a formula for calculating the run time of my APC battery system. I did a search but what I found required a particular model of apc. Total watts of computer and monitor is about 120 watts. Battery in my apc is 12V 18 Ah Thanks, Andy


[BBC] Einstein theory passes black hole test

Started by Mr. Man-wai Chang in sci.electronics.basics2 months ago 1 reply

[BBC]Einstein theory passes black hole test Full story: https://www.bbc.com/news/science-environment-44967491 The black hole at the centre of...

[BBC]Einstein theory passes black hole test Full story: https://www.bbc.com/news/science-environment-44967491 The black hole at the centre of our galaxy has helped astronomers confirm a key prediction of Albert Einstein's ideas. By observing a cluster of stars near the hole, they were able to confirm a phenomenon known as "gravitational redshift". It's when the wavelength of light ge...


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