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Type: Posts; User: flaxwalter

1. ## Thread: Temperature effect on diode function

by flaxwalter
Replies
16
Views
1,399

### Closed: Re: Temperature effect on diode function

Yes I know, my comment was only mathematically, analizing the function.
That's the reason I said in post #10

2. ## Thread: Temperature effect on diode function

by flaxwalter
Replies
16
Views
1,399

### Closed: Sorry, I meant "if I do Temp < - 273.15". Watch...

Sorry, I meant "if I do Temp < - 273.15". Watch how the curve turns right:
154798

you can also tabulate the graph using Excel and with this equation:
=1*10^-12*(EXP( (1.6 * 10^-19 * A1) / (1.38...
3. ## Thread: Temperature effect on diode function

by flaxwalter
Replies
16
Views
1,399

### Closed: Re: Temperature effect on diode function

Here you have my graph with Geogebra, also with negative Vd values:
look: -242 Celsius, (if I do Temp < 273.15 Celsius, the graph inverts to the right, but this is no the question, just saying)...
4. ## Thread: Temperature effect on diode function

by flaxwalter
Replies
16
Views
1,399

### Closed: Re: Temperature effect on diode function

Ok, let's see what happens with the function. I only graphed it using Geogebra:
154780
Edit: Oh, I dont know why this .gif does not animate.
I will try to put it in a web page.
But meanwhile I...
5. ## Thread: Temperature effect on diode function

by flaxwalter
Replies
16
Views
1,399

### Closed: Re: Temperature effect on diode function

Thanks, BraththeRad and FvM. This is what I mean:
154757
Yes, it is Shockley eq. I am trying to understand what you say. And I think that if Shockley eq. is a general equation, it should behave in...
6. ## Thread: Temperature effect on diode function

by flaxwalter
Replies
16
Views
1,399

### Closed: Re: Temperature effect on diode function

thank you, dick_freebird, (I dont understand what is tempco.) I mean if we only graph the equation, results what I said, I am only refering to graphing, If 1.- I do write 273 Kelvin, I get a curve....
7. ## Thread: Temperature effect on diode function

by flaxwalter
Replies
16
Views
1,399

### Closed: Temperature effect on diode function

Hi, I have a question about the diode equation function. If I graph vd versus id for a given temperature, it returns me a characteristic curve, but when I try with a higher temperature and I graph...
8. ## Thread: ELECTRICAL AND ELECTRONICS Instrumentation

by flaxwalter
Replies
34
Views
2,586

### Closed: Re: ELECTRICAL AND ELECTRONICS Instrumentation

1) I=2+4sin314t
2) 4 is the amplitude (or peak to peak) current.
3) But rms only takes the half and multiplies it by sqrt(2)/2, wich results 0.7071....
4) Then by superposition:...
9. ## Thread: How to upload a counter value to a website automatically

by flaxwalter
Replies
3
Views
3,508

### Closed: Re: How to upload a counter value to a website automatically

Thank you both for helping me. I finally could upload the counter using visual basic net. I did it uploading a text file and then reading the variables in a php page
10. ## Thread: help to design circuit (amplify tablet audio signal to speakers)

by flaxwalter
Replies
3
Views
430

### Closed: Re: I'd appreciate if you can help me to design a ciruit

(Your question is kind of very basic). You can use an audio ampliffier like the LM380 for example. You can even google it and get the details.
11. ## Thread: Replacing TTL logic with discrete components

by flaxwalter
Replies
8
Views
933

### Closed: Re: Replacing TTL logic with discrete components

I would do something like this. And perhaps add a stage with another transistor to invert the signal at the end. (I posted an application (flash swf) that calculates the resistors in a website...
12. ## Thread: released microcontroller's IO pins and noise

by flaxwalter
Replies
8
Views
841

### Closed: Re: released micomontroller`s IO pins and noise

As FvM says, you can decare them as output
13. ## Thread: How to upload a counter value to a website automatically

by flaxwalter
Replies
3
Views
3,508

### Closed: How to upload a counter value to a website automatically

Hi, I am designing a little system that counts de passsage of objects in a band, and I am trying to put that value in a website so that could be read anywhere. because I wish to watch it standing in...
14. ## Thread: Problem in triac circuit

by flaxwalter
Replies
15
Views
1,901

### Closed: Re: Problem in triac circuit

You can do this. Watch the change in the image.
(...Or something like that. Anyway I would try using Double Throw switches).126864
15. ## Thread: What is the value of this capacitor'

by flaxwalter
Replies
3
Views
672

### Closed: Re: What is the value of this capacitor'

(Thanks moh.haroun too.)
16. ## Thread: 12v battery voltage drop

by flaxwalter
Replies
19
Views
1,879

### Closed: Re: 12v battery voltage drop

May be your battery passed off. I sugest you to charge it for 1 day to see what happens. But when this type of battery lowers as to half, it is sure in bad form..
17. ## Thread: Power Electronics: SCR Switch Circuit Simulation / Theory

by flaxwalter
Replies
5
Views
1,113

### Closed: Re: Power Electronics: SCR Switch Circuit Simulation / Theory

I G= (Vcc - 2.2 - 0.6)/1000
If Vcc= 5V, then I G = 2.2 mA
If Vcc= 12V, then I G = 9.2 mA
It depends on the Vcc value.
Another thing: V_supply must not be negative, so -7V does not turn on the SCR.
18. ## Thread: What is the value of this capacitor'

by flaxwalter
Replies
3
Views
672

### Closed: What is the value of this capacitor'

Hi, I was using my laptop Toshiba Tecra A7, watching youtube videos, then suddenly i heard a little exploding noise. Then I opened the lap and after hours I found a broken compoent, It is a tantalium...
19. ## Thread: Operational Amplifier for a Voltage Summer

by flaxwalter
Replies
14
Views
945

### Closed: Re: Operational Amplifier for a Voltage Summer

No, he is right, a mixer is a summing amplifier.
That is exactly its job, to add signals.
20. ## Thread: Fluke 95 scopemeter goes crazy after some minutes

by flaxwalter
Replies
2
Views
984

### Closed: Re: Fluke 95 scopemeter goes crazy after some minutes

I'll check it. it is a 470uF at 25V. Near that C there are two inductors that get got, may be they radiate the C. Anyway I will replace it. Thanks. (I don't understand the "giving points" form yet).
21. ## Thread: Laptop not turning on

by flaxwalter
Replies
3
Views
991

### Closed: Re: Laptop not turning on

Check if the cleaning can has an indication like "dielectric" cleaner. If it says that, no problem with any short circuit. I have cleaned some connectors with a contact cleaner and turned on almost...
22. ## Thread: Fluke 95 scopemeter goes crazy after some minutes

by flaxwalter
Replies
2
Views
984

### Closed: Fluke 95 scopemeter goes crazy after some minutes

Hi, please. I have a Fluke 95 scopemeter wich had ever worked very well, but three monts ago some buttons stopped working, on turning on it does right measures on both meter and scope, but after five...
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