Formula for calculating run time of apc ?

Started by Andy in sci.electronics.basics3 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.basics3 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...


Update: Varistor/MOV Spice Modeling

Started by Jim Thompson in sci.electronics.basics4 months ago 30 replies

Varistor/MOV Spice Modeling has been updated. See VaristorMOV.zip on the Device Models & Subcircuits Page of my website. ...

Varistor/MOV Spice Modeling has been updated. See VaristorMOV.zip on the Device Models & Subcircuits Page of my website. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Sa...


three terminal volt regulator

Started by George Herold in sci.electronics.basics4 months ago 11 replies

Hi all, Simple question. Some 1/2 amp LM7805 is obselete (TO-220 pac) I need a replacement. So either a 1 amp...

Hi all, Simple question. Some 1/2 amp LM7805 is obselete (TO-220 pac) I need a replacement. So either a 1 amp 7805 http://www.onsemi.com/pub/Collateral/MC7800-D.PDF or a LM340 http://www.ti.com/lit/ds/symlink/lm340.pdf Is there any (practical) difference between the two? (besides the price.) George H.


An idea that may be of some use

Started by default in sci.electronics.basics4 months ago

I needed a small light to light some steps from my deck to the ground and in a few other places. I already had a 12V system outside. For a...

I needed a small light to light some steps from my deck to the ground and in a few other places. I already had a 12V system outside. For a cheap and dirty light I took a plastic test tube (ebay/amazon) put a short section of LED strip light into it (9 leds, served with wires) then heated the open end of the TT with a heat gun, and crimped it with a sheet metal pliers to make a waterproo...


sci.electronics.basics, Would You Like To Actually Participate In A Design ?

Started by Anonymous in sci.electronics.basics4 months ago 14 replies

This is an ESR detector for caps, electrolytics mainly that cause so many of the problems in electronic equipment. This is not meant to be a lab...

This is an ESR detector for caps, electrolytics mainly that cause so many of the problems in electronic equipment. This is not meant to be a lab quality instrument, it is mew=ant to be a fast way to check alot of caps and that does find many electronic problems. Nobody in the business will really argue with that unless they work on some weird shit. One of the earlier ones was t


mosfet bias question

Started by default in sci.electronics.basics4 months ago 3 replies

I plan to use a mosfet in a dawn to dusk switching circuit with a 12V regulated power supply. In the application notes they give the...

I plan to use a mosfet in a dawn to dusk switching circuit with a 12V regulated power supply. In the application notes they give the gate source absolute maximum voltage as +/- 10V Gate to Source. (page 1) On page 6 of the same application note they show a "Gate charge test circuit." with a 12 volt battery between the gate and source with a 50 Kohm variable resistor for the current source ...


juice the movie

Started by John Larkin in sci.electronics.basics4 months ago 1 reply

http://juicethemovie.com/ Looks interesting. -- John Larkin Highland Technology, Inc lunatic fringe electronics

http://juicethemovie.com/ Looks interesting. -- John Larkin Highland Technology, Inc lunatic fringe electronics


Sanity check for a cheap DVM

Started by bob prohaska in sci.electronics.basics5 months ago 6 replies

I'd like to check an old Radio Shack DVM for accuracy around 5 volts DC. On a brand-new cr2032 coin cell it measures 3.25 volts open...

I'd like to check an old Radio Shack DVM for accuracy around 5 volts DC. On a brand-new cr2032 coin cell it measures 3.25 volts open circuit, about 3.15 volts with a 3 kohm load. That's rather high compared to http://data.energizer.com/pdfs/cr2032.pdf, which shows ~2.95 V with a 15 kohm load. I've noticed that brand-new alkaline D cells seem to measure around 1.65 volts and credited it t...


Math Challenged.

Started by Anonymous in sci.electronics.basics5 months ago 14 replies

I know I am losing it, but I want to bring it back. I have screwed up some things. Figuring out a roll of wire, I had 95 turns of about 12"...

I know I am losing it, but I want to bring it back. I have screwed up some things. Figuring out a roll of wire, I had 95 turns of about 12" diameter. I thought pi was times radius, and that is because of not using it. And then I thought there was 1,700+ feet in a box that came with 1,000 feet. I had forgotten to divide by 12 to get feet out of inches. Losing it. Someone jus


Ask a Question to the Electronics-Related community

To significantly increase your chances of receiving answers, please make sure to:

  1. Use a meaningful title
  2. Express your question clearly and well
  3. Do not use this forum to promote your product, service or business
  4. Write in clear, grammatical, correctly-spelled language
  5. Do not post content that violates a copyright