Show Posts
Pages: 1 ... 30 31 [32] 33 34 ... 183
466  Using Arduino / General Electronics / Re: input voltage = forward voltage = no resistor required? on: March 05, 2014, 07:04:24 am
Quote
Mike although correct, is also wrong if you can keep the temperature at a constant which difficult to do with leds under a watt or so.
No Mike is also correct and correct.
It is totally impractical to keep a power LED at a constant temperature.
Even if you could keep a constant temperature, you can not stop the forward voltage changing with the age of the device.

However this is nothing to do with this thread as the LEDs involved are not power LEDs, they are just normal low current LEDs with built in resistors so no external resistors, or other form of current control, are required.

Nope mike is partly right... heatsink the led and it wont, just you can't really do that with low power leds (eg 5mm)
467  Using Arduino / General Electronics / Re: input voltage = forward voltage = no resistor required? on: March 05, 2014, 01:27:42 am
If your leds operate at a specific temperature/heatsinked, then driving them at a specific voltage would be safe, I don't believe "time" is a concern.

Eg a 10watt 4.2v rated led would be happy at a constant voltage and not die, but if the temp rises you risk destroying it... I have ran leds for days on end without any form of current regulation.

Mike although correct, is also wrong if you can keep the temperature at a constant which difficult to do with leds under a watt or so.
468  Using Arduino / LEDs and Multiplexing / Re: LED's with 12v internal resitor on: March 04, 2014, 05:55:16 pm
Maybe there is no internal resistor? And you have regular LEDs?
469  Using Arduino / LEDs and Multiplexing / Re: NEED HELP with This LED wiring on: March 04, 2014, 05:52:55 pm
I'm starting to see why people hate that fritz thing.

470  Using Arduino / Networking, Protocols, and Devices / Re: Unique MAC addresses? Best practice? on: March 04, 2014, 10:15:50 am
Just thinking out of the box..

Write a routine to generate a random mac address and store it in eeprom first time run...(if it's not already been generated)
471  Community / Website and Forum / Re: Anti Spam! on: March 04, 2014, 09:35:48 am
I think what's confusing here is "a new thread" on most forums, is a new thread, here it's a new "topic" but really, a new topic would mean a new topic eg "sewing" .

10 people click on "new topic" under "General Electronics" - now go inside General Electronics, you'll find 1 thread (if the forum was new and not been used) or you'd find that 1 thread along with everyone elses thread (topics)

So, you click on this thread, and inside that thread you'll find all 10 "topics" contained in 1 thread.

now, for those 10 "topics" to become those 10 threads (ie, individual topics), someone would have to reply to every post, otherwise it just stays contained in 1 thread... if 9 out of those 10 posts are all spam, then only 1 "topic" would be replied to, and that 1 topic would be removed from the thread of 10 posts bringing it to 9, and a new thread is created.

those 9 posts can be quickly deleted rather than relying on 9 "topics" to be individually removed after people have replied to them as normal.

yes  a complete redesign, but i believe this could be a much better way to capture trolls and spam, as all the "topic" posts are contained in just 1 thread.

renaming "post topic" to "post thread" or "new thread" would be less confusing  as  a topic about Elephants is really just a Thread about elephants in "off topic"
472  Using Arduino / Project Guidance / Re: Feasibility of Controlling a button with the Arduino and Tip 120 transistor on: March 04, 2014, 05:29:05 am
I wish you'd explain why you think the controller uses a reasonable amount of current...

I just don't believe it, any general pnp transistor should do the job... what am I missing?
473  Community / Website and Forum / Re: Anti Spam! on: March 04, 2014, 04:27:37 am
See this thread, yes the one you typed to reply...

Have ALL new posts appear in 1 thread...  when you reply to a one of the posts in the thread, it gets taken out (removed from the thread) and a new thread is spawned along with your reply.

Still no entiendo?
474  Products / Arduino Due / Re: I dropped my arduino and lost a capacitor... on: March 03, 2014, 11:28:17 pm
If you're desperate, use a couple of wires attach them to the contacts and then solder them to the capacitor..

The inductor you could just use the tip of the iron (if it's surface mounted)
475  Using Arduino / Project Guidance / Re: Feasibility of Controlling a button with the Arduino and Tip 120 transistor on: March 03, 2014, 07:07:46 pm
Place a multimeter in series and find out how much current is consumed with  a button press, I don't understand why it would be more than a few ma (except bad design)
476  Using Arduino / Project Guidance / Re: Power Switch on: March 03, 2014, 07:04:16 pm
Make a break on one of the wires before the dc jack plug, place a switch.

Unless you plan on current hungry devices being fed off the regulated 5v supply you'll be fine with almost any switch you find...
477  Using Arduino / Project Guidance / Re: Curious if anyone could give me some ideas/guidance on: March 03, 2014, 07:01:18 pm
Vague
478  Community / Website and Forum / Anti Spam! on: March 03, 2014, 06:47:07 pm
I got another idea.

In each topic (website and forum, General Electronics, Etc Etc) you make a post as normal, but in each topic, all the questions get grouped together as though it's one thread (eg, 10 posts, all get put into 1 thread, just like any replies, answers on this page) however, here's the twist.

hitting "Reply" button, takes that 1 post and spawns off a new thread, the person gets redirected to the new thread, and that 1 post gets removed from the old thread.

[ how to wire up a resistor]
My Issue
[Reply] [report]

[ how to use a mosfet]
My Issue
[Reply] [report]

[ how to calculate]
My Issue
[Reply] [report]




click on the reply to mosfet or any other, that post simply gets spawned into it's own thread, the idea is to trap all the spam into that 1 thread allowing a moderator to simply delete each *post* rather than having to remove an entire thread!  it also allows people to see all the new questions in 1 post.
479  Using Arduino / LEDs and Multiplexing / Re: Need ideas to control 8VAC Led strips on: March 03, 2014, 06:39:05 pm
Batteries tend to come in dc...

Leds will run on ac or dc, unless the circuit is expecting strictly ac.

Just try a low voltage dc with a resistor (3vdc - 300ohm resistor) , crank up the voltage until it lights... if it does not, pulsed DC might work, failing thay extract the led from each and repeat.
480  Using Arduino / LEDs and Multiplexing / Re: Need ideas to control 8VAC Led strips on: March 03, 2014, 06:17:48 pm
Controlling each strip is fine, controlling each led on the strip... nope

Pages: 1 ... 30 31 [32] 33 34 ... 183