Studied Electonics in college and know just enough to get myself in trouble ! This is for my current mod: Jays Beast I want to build two LED scales for fan control and temp readout... Here is the situation: Using 2 x 70mm fans to cool the tunnel I will be installing the PSU's in, I want to built one LED Scale for the output going to the fans, as I turn up the POT, each LED lights in sequence... The other LED scale, I want to light from top to bottom as the temp rises on the PSU's, I don't know if using a Thermistor is correct?? Can I use different valued resistors for each LED going in order to turn them on one by one?? Can anyone help me out?? I want to try and stay away from a Controller if possible..... Here is what I have so far: Also, I do not have a current supplier for electronic components, can anyone refer me to a dealer (website) in the US with decent prices?? Maybe someone who has supported the forum with a sponsorship??
If you would read my other posts , you will find that I always post in bold, I believe that it makes it easier to read ..... I'm not attempting to make it stand out or look more important.... I converted the graphic to a jpg....
You'll need specific circuits to do both these things. There are some banging about on the forums here. I'll see if I can root some out. EDIT: OK, :here: is a simple LED bar graph volt-meter, which works on 12V. Essentially you can rig it in parallel to the fan. It won't measure how fast the fan spins, but will reflect how many volts it gets. For a LED bar graph thermometer, you can use a circuit like :this:. EDIT EDIT: NiHiLiST did something similar for a fanbus. Unfortunately the picture links are now dead but his project was very tasty and he may be the person useful to talk to.
I would imagine most people who need bold text to be able to read it, set it so they have bold text, thankfully bold in my current font isn't particularly dificult to read, BMP graphics are also insane for web use, and many browsers can't display them converting to GIF or PNG will save download time and bandwidth, JPEG's suffer from artifacts which although invisible for 'real world' pictures, computer drawn images with there sharp lines can make a mess, espically of text in those images. My main gripe would be that you clearly havn't searched the past few days of topics as LED bar inidcators have come up very recently. Though I found this nice page today: http://casemods.pointofnoreturn.org/voltmon/tutorial-full.html On a general Electronics note, when drawing up digital circuits, avoid using the mains/chasis earth symbol, use '0v' or the 'digital earth' symbols in preference, as in some situations there is a voltage diference between them.
Guess you didn't read either, I stated that I forgot, had full intentions, but just forgot..... All the current LED applications that I found were for IC's, as stated above, I was attempting to stay away from chips, but I'm not knowledgable enough to know if it was possible with varied resistance...... IE... the complete reason for this topic! Didn't know I was being graded on drawing up a circuit.... According to: http://www.everythingradio.com/electrical_schematic_symbols.htm there isn't any difference... This forum is to help people and the sharing of information to assist each other. why don't you give me a link that explains the difference between grounds so I can learn something to......
From what I remember the other forums started out as people seeking resistor solutions and they were taken around to adopt the IC solution. If you imagine your lowest voltage LED, say around 3v you want it to come on, the LED drops 1.5v and you'd probably want 20mA to light it, giving a resistor of 75 ohms, to light your top LED, at 7v, regardless of what resistor you'd be using, your 3v led would be recieving 73mA when you up the voltage to 7v, most likely enough to fry it. I'm sorry about not reading the details of your BMP/JPEG post, and I'm also sorry I couln't find any easy explanations of the diferent ground symbols (reference I was using, was rather confusing and didn't want to inflict it on you), and would like to thank cpemma for providing a link which explains how all grounds are not equal , I didn't intend it to be grading your diagram, just helpful advice, but I can see if you were feeling guarded after the jpeg bit, you'd not have taken it as lightly as I indended, sorry again.. I'll try and make my posts in future a little more, friendly.
After looking at several diagrams, the resistance formula and ideas behind how it works are coming back to me from college.... Using the links that were given, I have already ordered the chips.... to build the circuits... I hope to add the diagrams here and build a webpage of how-to so cpemma will have another reference Guess I've had a lot going on at work and I'm a little touchy, I apologize!! Thank you for your help!! We can only hope the best for the new LED scales...
this may or may not help you, http://www.electronics-lab.com/projects/motor_light/006/ I built a couple of these to quiet my kids PC which is in my living room. they work very nicely. un less you like to turn the knobs to adjust your fan speeds manualy. this thing is fast responding to temperatures too.
