Bipolar current limit

Started by George Herold in sci.electronics.basics10 hours ago 15 replies

OK this is perhaps overkill.. see footnote. So I've got an indicator LED (bi-color) the input is the error term from a thermal loop, and I turn...

OK this is perhaps overkill.. see footnote. So I've got an indicator LED (bi-color) the input is the error term from a thermal loop, and I turn that into an LED current. I was thinking it might be nice to turn up the gain on the current, but then I worried about burning out the LED with too much current from the opamp.* So I drew this up... and then added the diodes to stop the trans...


Connector rant

Started by George Herold in sci.electronics.basics6 days ago 11 replies

Sorry I spent part of the morning looking for a connector.. pcb-pcb right angle. So why are connectors more expensive than opamps? And why...

Sorry I spent part of the morning looking for a connector.. pcb-pcb right angle. So why are connectors more expensive than opamps? And why is a 2X8 connector ~$1.50 cheaper than it's 2X6 brother? https://octopart.com/search?q=66953-008lf https://octopart.com/search?q=66953-006lf Does anyone have a favorite connector brand? We've got some Amphenol types in stock and after being over...


Transistor circuits, book, devices, etc

Started by Peter Percival in sci.electronics.basics6 days ago 49 replies

I though I'd like to learn a bit about electronics and to that end I'd like to buy a book of transistor circuits, a breadboard, and various...

I though I'd like to learn a bit about electronics and to that end I'd like to buy a book of transistor circuits, a breadboard, and various components to experiment. Can anyone recommend a book that uses transistors that I can buy in the UK? Also, who is a good supplier of components generally? -- Do, as a concession to my poor wits, Lord Darlington, just explain to me what you reall...


Top Science Rule

Started by Anonymous in sci.electronics.basics1 week ago 1 reply

http://www.rbduncan.com/toprule.htm

http://www.rbduncan.com/toprule.htm


Sayonara, Eagle

Started by Phil Hobbs in sci.electronics.basics1 week ago 25 replies

So, I got an email from Autodesk announcing that Eagle is now software-as-a-service, with the pro version renting for $65 per month per...

So, I got an email from Autodesk announcing that Eagle is now software-as-a-service, with the pro version renting for $65 per month per seat. Sayonara, Eagle. Too bad. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs ...


[FoxNews]A small town's sudden power surge fried tech gear in hundreds of homes

Started by Mr. Man-wai Chang in sci.electronics.basics2 weeks ago 24 replies

A small town's sudden power surge fried tech gear in hundreds of homes Full story:...

A small town's sudden power surge fried tech gear in hundreds of homes Full story: http://www.foxnews.com/tech/2017/01/31/small-town-sudden-power-surge-fried-tech-gear-in-hundreds -homes.html Residents in the small Pennsylvania town of Brookville must've wondered what on earth was going on earlier this month when a sudden power surge caused electrical appliances and gizmos in up to 1,


relay circuit

Started by RKC in sci.electronics.basics2 weeks ago 9 replies

Hello- I need help in designing a circuit which would take an input from any of 3 momentary switches and then operate a relay. The relay needs...

Hello- I need help in designing a circuit which would take an input from any of 3 momentary switches and then operate a relay. The relay needs to latch but only after any of the momentary switches have been made for > 1sec or the relay will not operate. it would be helpful if there was an additional switch added to reset the circuit Preferred voltage is 12V DC. Thanks RC


Lumen / $ Ratio Up to 800 With Dollar Tree LEDs

Started by Bret Cahill in sci.electronics.basics3 weeks ago 2 replies

Admittedly this ratio isn't as famous as earnings/dividend but . . . Bret Cahill

Admittedly this ratio isn't as famous as earnings/dividend but . . . Bret Cahill


Electric Motor Cost/Watt Is Impervious To Size

Started by Bret Cahill in sci.electronics.basics3 weeks ago 4 replies

There doesn't seem to be much in the way of economies of scale when it comes to the cost/watt of electric motors. Most 50 kW motors cost...

There doesn't seem to be much in the way of economies of scale when it comes to the cost/watt of electric motors. Most 50 kW motors cost between 6 cents / watt and 20 cents / watt. Most 1 kW motors cost between 6 cents / watt and 20 cents / watt. Is this simply a matter of materials volume/ weight and therefore costs are linear with power? Bret Cahill


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