| Trouble with a simple project with ULN2803 | | 01/01/70 00:00 |
| Start to search step by step | | 01/01/70 00:00 |
| back to breadboard | | 01/01/70 00:00 |
| No surprise... | | 01/01/70 00:00 |
| Thanks Kai | | 01/01/70 00:00 |
| In short | | 01/01/70 00:00 |
| Then have a look at the datasheet! | | 01/01/70 00:00 |
| Don't think so | | 01/01/70 00:00 |
| No, Per, the actual reason is... | | 01/01/70 00:00 |
| 'working' again | | 01/01/70 00:00 |
| But why? | | 01/01/70 00:00 |
| Lack of knowledge of the unknown | | 01/01/70 00:00 |
| Ah yes | | 01/01/70 00:00 |
| I think people don't just realize how much they do not know. | | 01/01/70 00:00 |
| There is a reason ... | | 01/01/70 00:00 |
| why was working with the other microcontroller | | 01/01/70 00:00 |
| Keep in mind it's on a "breadboard" | | 01/01/70 00:00 |
| Infinite Improbability Drive? | | 01/01/70 00:00 |
| re: Infinite Improbability Drive | | 01/01/70 00:00 |
| Pah | | 01/01/70 00:00 |
| Vote: Offensive/Flame! | | 01/01/70 00:00 |
| ;-) | | 01/01/70 00:00 |
| Reference for the uninitiated | | 01/01/70 00:00 |
| Without pull-up??? | | 01/01/70 00:00 |
| because it was not working, but 'working' | | 01/01/70 00:00 |
| What else is on your board... | | 01/01/70 00:00 |
| It's a transistor array ... not a magic box | | 01/01/70 00:00 |
| AGAIN!!! =( | | 01/01/70 00:00 |
| What are you connecting to outputs? | | 01/01/70 00:00 |
| Yes...! | | 01/01/70 00:00 |
| new measures with load | | 01/01/70 00:00 |
| How? | | 01/01/70 00:00 |
| Can use an oscilloscope? | | 01/01/70 00:00 |
| Laser and oscilloscope | | 01/01/70 00:00 |
| Need current control, not voltage control | | 01/01/70 00:00 |
| re Per | | 01/01/70 00:00 |
| Definitely a good way go let out the magic smoke | | 01/01/70 00:00 |
| not even then | | 01/01/70 00:00 |
| The problem is not the laser. | | 01/01/70 00:00 |
| Drive the ULN harder. | | 01/01/70 00:00 |
| Factor 10 off? | | 01/01/70 00:00 |
| I guess, you forgot the Ucesat of ULN2803... | | 01/01/70 00:00 |
| 74HC04 | | 01/01/70 00:00 |
| Better to have them.. | | 01/01/70 00:00 |
| up the garden path | | 01/01/70 00:00 |
| Definitely consider min/max values from datasheet | | 01/01/70 00:00 |
| Nothing more instructive than... | | 01/01/70 00:00 |
| but he won't | | 01/01/70 00:00 |
| Yes, that's true... | | 01/01/70 00:00 |
| a better way | | 01/01/70 00:00 |
| Datasheet | | 01/01/70 00:00 |
| OH BOY | | 01/01/70 00:00 |
| Logic level MOSFET... | | 01/01/70 00:00 |
| A new test I made, bizarre... | | 01/01/70 00:00 |
| It seems the power supply... | | 01/01/70 00:00 |
| Lack of information | | 01/01/70 00:00 |
| yep. It IS very much! | | 01/01/70 00:00 |
| Laser and peltier | | 01/01/70 00:00 |
| Dont konw wich regulator you use. | | 01/01/70 00:00 |
| well... no regulator at all... | | 01/01/70 00:00 |
| PC supplies are not very well regulated | | 01/01/70 00:00 |
| For 3V you should have a 3V regulator | | 01/01/70 00:00 |
| That's the explanation! | | 01/01/70 00:00 |
| 3v | | 01/01/70 00:00 |
| Minimum load | | 01/01/70 00:00 |
| Supply and 7805 | | 01/01/70 00:00 |
| you want help?? | | 01/01/70 00:00 |
| No laser Datasheet | | 01/01/70 00:00 |
| then return it and DEMAND one with a datasheet | | 01/01/70 00:00 |
| Already mentioned lack of datasheet | | 01/01/70 00:00 |
| suggested as first step | | 01/01/70 00:00 |
| laser | | 01/01/70 00:00 |
| Hard to tell but I think you should mind the voltage | | 01/01/70 00:00 |
| Perhaps you should use an adjustable regulator | | 01/01/70 00:00 |
| I do not think so | | 01/01/70 00:00 |
| and how would YOU build a current source? | | 01/01/70 00:00 |
| line anyone else - a 'cookbook' design | | 01/01/70 00:00 |
| can you do that without a regulated voltage source? | | 01/01/70 00:00 |
| yes | | 01/01/70 00:00 |
| Guys, Chico has a Laser modul, already... | | 01/01/70 00:00 |
| two possibilities | | 01/01/70 00:00 |
| assumptions are dangerous | | 01/01/70 00:00 |
| But I didn't assume, that it has a good current control! | | 01/01/70 00:00 |
| Stable is one thing - what voltage is another | | 01/01/70 00:00 |
| If only Chico had sent us a link to his Laser modul... | | 01/01/70 00:00 |
| probably highly unstable | | 01/01/70 00:00 |
| Yes, and a good linear regulator can supply that! | | 01/01/70 00:00 |
| That was my point! | | 01/01/70 00:00 |
| we can't know for certain, but ... | | 01/01/70 00:00 |
| What is an ST2221 | | 01/01/70 00:00 |
| ST2221a != ST2221 | | 01/01/70 00:00 |
| didn't you notice the reference to an earlier post? | | 01/01/70 00:00 |
| you will need one of these | | 01/01/70 00:00 |
| Yes, if you have a good, stabile supply without much noise | | 01/01/70 00:00 |
| A current source isn't a magic beast | | 01/01/70 00:00 |
| ... but only if ... | | 01/01/70 00:00 |
| and I thought this was turkey day | | 01/01/70 00:00 |
| Are you assuming CC has to be passive? | | 01/01/70 00:00 |
| that would be ridiculous | | 01/01/70 00:00 |
| Ask Richard. | | 01/01/70 00:00 |
| other than Richard? | | 01/01/70 00:00 |
| Now define "constant" | | 01/01/70 00:00 |
| Consider this ... | | 01/01/70 00:00 |
| Of course, it is... | | 01/01/70 00:00 |
| Current control != Constant Current | | 01/01/70 00:00 |
| irrelevant | | 01/01/70 00:00 |
| Why do you continue in this way, Erik? | | 01/01/70 00:00 |
| Minimalistic const current regulator | | 01/01/70 00:00 |
| It's a matter of definition | | 01/01/70 00:00 |
| Ideal constant current source... | | 01/01/70 00:00 |
| That's where this whole thing began ... | | 01/01/70 00:00 |
| Don't jump around wildly when cornered | | 01/01/70 00:00 |
| That's not what was said | | 01/01/70 00:00 |
| That's why we should avoid to offend each other... | | 01/01/70 00:00 |
| Still trying to smash in open doors | | 01/01/70 00:00 |
| The world is flat! | | 01/01/70 00:00 |
| VERY "poor choice of wording" | | 01/01/70 00:00 |
| It wasn't MY wording to which I referred, Erik | | 01/01/70 00:00 |
| Memory lapse? | | 01/01/70 00:00 |
| You missed the point, Per | | 01/01/70 00:00 |
| I didn't even bother .... | | 01/01/70 00:00 |
| Why, then did you mention it? | | 01/01/70 00:00 |
| Lots of ridiculous claims later... | | 01/01/70 00:00 |
| ABSOLUTELY NOT | | 01/01/70 00:00 |
| Cunning ? | | 01/01/70 00:00 |
| Perhaps, but ... | | 01/01/70 00:00 |
| What definition? CC/CV both have line regulation tolerances | | 01/01/70 00:00 |
| same old, same old, same old | | 01/01/70 00:00 |
| There you go again ... waving your hands ... | | 01/01/70 00:00 |
| already answered | | 01/01/70 00:00 |
| is that what you think? | | 01/01/70 00:00 |
| language, language, language | | 01/01/70 00:00 |
| a rose by any other name ... | | 01/01/70 00:00 |
| nearly any linear regulator can do that | | 01/01/70 00:00 |
| Yes, indeed | | 01/01/70 00:00 |
| confound it!!! | | 01/01/70 00:00 |
| Will an AC supply be adequate for you? | | 01/01/70 00:00 |
| that does not deserve an answer | | 01/01/70 00:00 |
| If not, then show us what is adequate! | | 01/01/70 00:00 |
| Now see here ... | | 01/01/70 00:00 |
| Not according to the datasheet I have ... | | 01/01/70 00:00 |
| of course it does | | 01/01/70 00:00 |
| So what does that schematic mean? | | 01/01/70 00:00 |
| re your babble about a constant supply voltage | | 01/01/70 00:00 |
| If that were the case ... | | 01/01/70 00:00 |
| Time to return to earth. | | 01/01/70 00:00 |
| What are you trying to prove? | | 01/01/70 00:00 |
| Perhaps, but one with no supply? | | 01/01/70 00:00 |
| NOBODY, NOBODY can make this work .... | | 01/01/70 00:00 |
| How about LM317? Look it up! | | 01/01/70 00:00 |
| As I said here... | | 01/01/70 00:00 |
| Just a minute, Chico ... | | 01/01/70 00:00 |
| Double check | | 01/01/70 00:00 |
| I see no pullups | | 01/01/70 00:00 |
| "The commom of the resistor array is connected to +5v" | | 01/01/70 00:00 |
| Not what I mean! | | 01/01/70 00:00 |
| He probably needs pullups on both inputs and outputs. | | 01/01/70 00:00 |
| be specific!!! | | 01/01/70 00:00 |
| Now I understand ... | | 01/01/70 00:00 |
| au contraire | | 01/01/70 00:00 |
| Gate Threshold Voltage, what is? | | 01/01/70 00:00 |
| Did you really try Google? | | 01/01/70 00:00 |
| I tried google... | | 01/01/70 00:00 |
| Vgs > Vgs(th)! | | 01/01/70 00:00 |
| I GAVE UP! | | 01/01/70 00:00 |
| Don't give up! | | 01/01/70 00:00 |
| Yes, don't give up! | | 01/01/70 00:00 |
DONT GIVE UP, did you try ... | | 01/01/70 00:00 |
