5614 Posted August 31, 2004 Share Posted August 31, 2004 3.5CD means avoid eye contact?? cccccooolllll, im such a kid when it comes to stuff like that.... a good mains feeding should work! nah, i think it wants: Forward voltage at IF=20mA: 1.8V Forward current (max): 30mA Reverse voltage: 5V Power dissipation (max): 100mW no transformer needed for that its battery anyway, transformer wouldnt work... does a pulsed DC current work in transformers? i dont think it will, coz AC is back and forward, pulsed DC is on/off... Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 pulsed DC works quite well in transformers! even better if they`re frequency tuned as well Link to comment Share on other sites More sharing options...
pulkit Posted August 31, 2004 Share Posted August 31, 2004 pulsed DC works quite well in transformers!even better if they`re frequency tuned as well Surely there has to be a minimum frequency barrier over which pulsed DC gives acceptable results, what sort of frequency would that be ? A few 100Hz ? Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 totaly dependant on the Q of the primary winding. it`s impossible to answer, it`s like saying what amount of power with a resistor take? ) Link to comment Share on other sites More sharing options...
pulkit Posted August 31, 2004 Share Posted August 31, 2004 What do you mean by Q ? I am guessing ........ quality factor ? Link to comment Share on other sites More sharing options...
5614 Posted August 31, 2004 Share Posted August 31, 2004 im sure Q is charge... but that dont make sense "the charge of the primary winding" so im not sure Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 Q=Impedence Link to comment Share on other sites More sharing options...
5614 Posted August 31, 2004 Share Posted August 31, 2004 oh, ok, im sure Q can symbolise charge sometimes though! Link to comment Share on other sites More sharing options...
pulkit Posted August 31, 2004 Share Posted August 31, 2004 If you take the impedence into account, is it possible to work out a mathematical expression for minimum frequency for acceptable output ? (Assuming, you can define acceptable in quantitative terms) Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 not exactly "minimum" no, optimum yes. taking into account inductance (Henrys) and self capacitance, winding`s (amount, material and diameter and insulation dielectrics over thermal gradients) the core type, and power used, there are equasions to calculate this however, it`s been MANY YEARS since I did all this crap, and now I just buy them off the shelf Link to comment Share on other sites More sharing options...
5614 Posted August 31, 2004 Share Posted August 31, 2004 "i buy it off the shelf" ROFLOL! 3.5CD means avoid eye contact?? Forward voltage at IF=20mA: 1.8V Forward current (max): 30mA Reverse voltage: 5V Power dissipation (max): 100mW quoting myself! so' date=' 3.5CD... will that blind? or just make you blink or what, what CD is a normal 100W light bulb that you plug into your ceiling? those stats about the [i']hyper-bright [/i] LED [wow!] um, yeah, whats the difference between reverse voltage and normal voltage, obviously you could just switch the legs of the LED around, but why would there be a difference? Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 not blind no, but a second glimpse will leave spots in front of your eyes for quite some time, and prolonged exposure may cause permanent eye damage and LED is a Diode, it allows current to pass one way only, However they do have a breakdown voltage if a current is applied in the wrong direction (known as the PIV). ordinary diods will "blow" at this power or above, making them useless, there are Exceptions such as the Zenner Diode, when it`s PIV is reached it conducts in the other direction also, with no damage done to it. Link to comment Share on other sites More sharing options...
5614 Posted August 31, 2004 Share Posted August 31, 2004 ok about looking at the LED i know about LED = light emmiting diode PIV = Peak Inverse Voltage this is a bit random, but you can get bi-colour LEDs which work by reversing the current, i really want to plug it into the mains, but i need a step down transformer big-time, i think this bi-colour LED works on 5V max! whats the frequency of the mains? i cant remember.....? Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 bi-color are back to back leds in the same cup, the forwards voltage isn`t the same as the reverse voltage though, and so they`re protected by that as well as by design. as for mains freq, it depends where you live, in UK and Russia it`s 50cps, in usa and canada its 60cps. Link to comment Share on other sites More sharing options...
5614 Posted August 31, 2004 Share Posted August 31, 2004 what kinda candle power is a normal 100W bulb [in the UK] the kind which you fit into your ceiling? just trying to get an idea comparing it to the 3.5CDpower of the LED, its just that doesnt sound very bright, although as its called hyper-bright, i will take your word for it! Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 I`ve no idea in all honesty, but several hundred would be an educated guess. however you CANNOT compare the two, one is omni-directional and multi frequency. the other is focused and single freq, think of this, you may stare at a 100w bulb for an hour and suffer maybe 10 mins of "spots" in front of your eyes. 30 seconds of a 5mw yes 0.005 watt laser and go nearly blind permanently! how many 0.005s are in 100.0? Link to comment Share on other sites More sharing options...
5614 Posted August 31, 2004 Share Posted August 31, 2004 yeah, i thought the answer might be along those lines...... seeing as this thread has changed topics slightly, dont bother splitting it, but i was wondering how you can build a laser..... a, light amplification by stimulation and emmission of radiation [l.a.s.e.r]? Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 it`s not all that difficult at all, and yes I`m more than familiar with what Laser means they even sell them in Kit Form but the Really fun ones are costly, but again, simple to make if you have the cash Link to comment Share on other sites More sharing options...
5614 Posted August 31, 2004 Share Posted August 31, 2004 i wasnt suggestion you didnt know what a laser was, you made one yourself, its on your site, in the pics, i said it so that you know what i know what it is, i just dunno how to make one, did you get yours in a kit? i was thinking along the lines of, in laser pens theres [i think] a single laser diode of some sort, (you know, the tiny handheld laser pens) i was wondering if you could make something like that, and if not, could you make any laser. Link to comment Share on other sites More sharing options...
YT2095 Posted August 31, 2004 Share Posted August 31, 2004 You or indeed I have NO CHANCE of making a semiconductor laser so you can forget THAT idea! LOL but "classical" lasers aren`t that hard if you have the parts (the guts from a laser printer, especialy the optics are always handy!) YAGs or HeNeAr kits are out there and have been since the mid 70`s, and the prices are pretty good now too Link to comment Share on other sites More sharing options...
vrkelley Posted September 1, 2004 Share Posted September 1, 2004 dont think to reduce 18V --> 12V, so i think he is making the .3amps figure up doh! Right you are! That 8 LED Trailer (12V) array has a draw about .035 amp NOT .3 ! Link to comment Share on other sites More sharing options...
vrkelley Posted September 1, 2004 Share Posted September 1, 2004 the 1.5 cd (color dome) has a visibility of about 1mile for Red, Gr, Wh, Yel, Blu You can concentrate the light by getting LEDs with a lower degree of visibility so like 60Degrees spreads the light out...9 degrees is pretty concentrated. Also you can add a reflector to boost the light source. Link to comment Share on other sites More sharing options...
5614 Posted September 1, 2004 Share Posted September 1, 2004 to convert DC --> AC using a 555 IC please see: http://www.uoguelph.ca/~antoon/circ/555dcac.html Link to comment Share on other sites More sharing options...
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