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Author Topic: Some diode question for the clean up....  (Read 1276 times)

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Offline TrickyNekroTopic starter

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Some diode question for the clean up....
« on: January 28, 2009, 05:46:48 PM »
Hello guys,

My question is simple...
I want to switch a transistor.... but.... I really need to add this switch and 5V power to the switch instead of 12V
is a no no go....
what I want to ask is, if this diode protects my atmega from any 12V....
I know a voltage follower is much better... but I have to try this first...


Thanks in advance,
Lefteris,
Greece
« Last Edit: January 28, 2009, 05:48:06 PM by TrickyNekro »
For whom the interrupts toll...


P.S. I've been inactive for almost a year... Don't give promises but I'll try to complete my tutorials. I'll let you know when..

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Offline MaltiK

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Re: Some diode question for the clean up....
« Reply #1 on: January 28, 2009, 06:11:51 PM »
I think its much more difficult than that if you want a specified voltage. You are probably more knowledgeable than me at this but I'll give it a shot. Theoretically it should work because all a regulator is, is a couple of zener diodes in one direction (input rail) and a couple of caps and resistors on the output rail (regulated 5v) But since you have an input voltage above 5v, you will have to do some math to find the suitable amount/value of the components required.

Shot in the dark?
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Offline TrickyNekroTopic starter

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Re: Some diode question for the clean up....
« Reply #2 on: January 28, 2009, 06:19:59 PM »
Basically, I don't really mind voltage...
The whole thing I'm trying to do is a battery protector, that has zero battery drain until
activated....
It is difficult but not impossible...
The switch is there to enable some bipolar transistor that drive a power MOSFET....
since I'm using MOSFET and two transistor everything seems all right....

Truth is... that the shot missed slightly.... but thanks a lot for the try!!!

I tested the circuit, as configured above.... and it worked....
But I need to know everything else...

So if I miss something or have a better idea, please tell...


Thanks in advance,
Lefteris,
Greece
For whom the interrupts toll...


P.S. I've been inactive for almost a year... Don't give promises but I'll try to complete my tutorials. I'll let you know when..

Cheers!

Offline fuzzyt

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Re: Some diode question for the clean up....
« Reply #3 on: January 28, 2009, 06:27:53 PM »
Yes, the diode should protect the uC from the 12V.  Just remember you'll have around a 0.7V drop across the diode, if that matters.

Offline MaltiK

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Re: Some diode question for the clean up....
« Reply #4 on: January 28, 2009, 06:52:00 PM »
Basically, I don't really mind voltage...
The whole thing I'm trying to do is a battery protector, that has zero battery drain until
activated....
It is difficult but not impossible...
The switch is there to enable some bipolar transistor that drive a power MOSFET....
since I'm using MOSFET and two transistor everything seems all right....

Truth is... that the shot missed slightly.... but thanks a lot for the try!!!

I tested the circuit, as configured above.... and it worked....
But I need to know everything else...

So if I miss something or have a better idea, please tell...


Thanks in advance,
Lefteris,
Greece

Haha I misread your post... well it was a good try I guess :D
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Offline TrickyNekroTopic starter

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Re: Some diode question for the clean up....
« Reply #5 on: January 29, 2009, 03:52:16 AM »
The problem is solved, experimentally tested!!! ;D

Thanks for the reply guys!!!
For whom the interrupts toll...


P.S. I've been inactive for almost a year... Don't give promises but I'll try to complete my tutorials. I'll let you know when..

Cheers!

 


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