Search found 1507 matches

by dyarker
Sat Dec 01, 2018 7:07 am
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 374

Re: need help to find blue led bulb

I guess you never looked at an LED spec sheet either! LED Reverse voltage 5V PERIOD! LED "bulbs" would have a diode and current limiting (probably not resistor) built in. Dacflyer is not looking for a single blue LED "bulb" at 120VAC. According to link he wants equivelent light to 10W incandescent i...
by dyarker
Fri Nov 30, 2018 1:18 pm
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 374

Re: need help to find blue led bulb

Additional- A resistor's power rating is based on it's max power in free air which is at 25°C. Your calculation for 5mA was still 0.6W. Inside the base and bulb is not free air, it is not 25°C, and the resistor is not alone. So with thermal conductive epoxy (to move heat to metal shell) it might get...
by dyarker
Fri Nov 30, 2018 12:53 pm
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 374

Re: need help to find blue led bulb

You did not look at the page at the link Dacflyer gave. The calculations were for a bulb like that, not a single indicator LED. An LED is a diode, but the PIV is like 5V. For use in a 120VAC circuit another diode (or bridge) with a PIV of at least 200V is needed. With all components in the bulb, The...
by dyarker
Fri Nov 30, 2018 7:53 am
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 374

Re: need help to find blue led bulb

I never said your dual contact socket had power on the shell. I was answering Externet who said a bayonet would expose 120VAC. Even if shell were used, properly connected it would be safe. Repeat, I DID NOT (NOT) say your setup used the shell for power. From the page you linked, it seems it contains...
by dyarker
Fri Nov 30, 2018 4:32 am
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 374

Re: need help to find blue led bulb

A dropping resistor for 120VAC would be a huge beast. A dropping capacitor wastes a LOT less power.

And because it is for AC a rectifier is also needed.

Cheers,
by dyarker
Thu Nov 29, 2018 1:28 pm
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 374

Re: need help to find blue led bulb

Dacflyer, Then how would the shell get 120VAC on it like Externet suggested. In vehicles dual contact bulbs are sometimes used for brake and turn signal. The bulbs have two elements, one contact to each ans the shell is common return. So not using shell at all for electrical contact doubles the no p...
by dyarker
Tue Nov 27, 2018 5:54 pm
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 374

Re: need help to find blue led bulb

I believe they are not made/marketed because when inserting/replacing such bayonet bulb, the outer case terminal is exposing 120VAC to fingers.
???Neutral to shell, switched hot to contact.
by dyarker
Tue Nov 27, 2018 12:59 pm
Forum: General Discussion
Topic: need help to find blue led bulb
Replies: 17
Views: 374

Re: need help to find blue led bulb

... makes them look very faded. Because they are! A white "LED" is really a blue LED with fluorescent elements. Some blue light causes some green fluorescence. Some blue light causes some red fluorescence. Some blue light leaks out. The combination makes white. A blue filter absorbs 2/3s of the lig...
by dyarker
Fri Nov 23, 2018 3:49 am
Forum: General Discussion
Topic: Im happy I now registered
Replies: 0
Views: 235

SPAM

2nd is SPAM
1st just a waste of space
by dyarker
Wed Nov 21, 2018 4:53 am
Forum: General Discussion
Topic: Edenpure Classic space heater...NOT LEVEL
Replies: 17
Views: 2804

Re: Edenpure Classic space heater...NOT LEVEL

Copper is also more expensive.

People that don't know/care about a fairly small difference in performance and appearance go for the cheaper. so that is what mostly made. Others buy more expensive thinds for long term cost efficiency or "status".
by dyarker
Tue Nov 20, 2018 4:12 am
Forum: General Discussion
Topic: How to select the Gate Drive Resistor
Replies: 4
Views: 130

Re: How to select the Gate Drive Resistor

Like I said before for the power filter capacitor, doing the math will pick the components.

See if you can find a copy of Fundamentals of Electronic Devices by Ronald J. Tocci.

I am not reference material for a paper.

Turn cell phone off in class.

Cheers,
by dyarker
Mon Nov 19, 2018 2:47 pm
Forum: General Discussion
Topic: Edenpure Classic space heater...NOT LEVEL
Replies: 17
Views: 2804

Re: Edenpure Classic space heater...NOT LEVEL

not sure what the advantage is.
copper is a better heat conductor
by dyarker
Fri Nov 16, 2018 12:08 pm
Forum: General Discussion
Topic: Forum Update! Secure!
Replies: 16
Views: 663

Re: Forum Update! Secure!

((even the spammers were encrypted while created user accounts :grin: , (different protection called for)))
by dyarker
Fri Nov 16, 2018 4:16 am
Forum: General Discussion
Topic: How to select the Gate Drive Resistor
Replies: 4
Views: 130

Re: How to select the Gate Drive Resistor

What is your major?
by dyarker
Thu Nov 08, 2018 12:33 pm
Forum: General Discussion
Topic: Microphone in a bubble...
Replies: 7
Views: 210

Re: Microphone in a bubble...

Oh yeah! How waterproof? Rain/spit/sweat? Or, submerged? (and depth?)