Call me crazy, but why not replace pulldown resistor R2 with a small trimpot and simply adjust it until the unwanted behavior disappears?
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Call me crazy, but why not replace pulldown resistor R2 with a small trimpot and simply adjust it until the unwanted behavior disappears?
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Clarify that "...all that EMI to the ground..." sentence.... which EMI, Where?
Your base resistor is a tad high (well... for a purist)
Are you aware of TIP122 internal resistors?
R2 shouldn't be needed
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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Ehm guys... thank you but I kinda.. solved the problem.
Thank you anyway.
Cya soon.
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Thanks for posting your solution here with as this much details, all forum member and reader will learn a lot from it
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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Did you try a capacitor instead of R2?
And how did you solve the problem? Inquiring minds want to know . . .
Last edited by RussMartin; - 10th February 2009 at 01:43.
Russ
N0EVC, xWB6ONT, xWN6ONT
"Easy to use" is easy to say.
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I think I have told you that already in the first post. When I connected the osciloscope on the led I found so much "noise" in the wave form. The circuit is suposed to generate some frequencies that will blink the 3W leds... So if you look at one led with the osciloscope, you will see a square waveform, of maximum amplitude of 5V and minimum amplitude of 0V. Due to the noise (the EMI/RFI not ESD sorry for that) the wave form gets messed, mainly during the 0V period of the waveform.. the noise creates some pikes on the 0V periode wich ones gets close to the 5V... enough to activate the TIP122 cause its gain is really high (10000). So even with the circuit completly turned off, that noise makes the leds to blink.Originally Posted by mister_e
Yes I know.. you will crucify me but I didnt take much care of it..
Yes I heard about that... as it seems, they arent sufficient for preventig that damn noise..
Yes I think the same but that thing is the only thing that solved my problem..
It sends to the ground all the EMI/RFI issues that circuit may suffer.. As far as I know..
I was afraid of using a capacitor cause it could drawn my frequency, so I chose the resistor to send it to dust!
Im sorry for taking that long time for answering, I dont wanna be selfish mr e, I just cant explain better it takes me a really long time to translate.. -> bad english, remember that!
Ty guys, hope this thing can be useful.
Cya soon!
Last edited by r0nd0m; - 10th February 2009 at 20:57.
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Don't take my comment as an offense. To be honest, I would like to apologize for that. It was one of those bad days... sorry
Don't worry about your English... I really do understand what you mean and how you feel... I'm French... but Canadian/Quebecer ( va chier Alain)
Steve
It's not a bug, it's a random feature.
There's no problem, only learning opportunities.
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lol, thats ok mate
Cya soon guys!
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