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1  International / Generale / Re: Problema voltaggio per led su Vespa 1976 on: June 11, 2013, 05:05:39 pm
Ho anche visto questo come sistema ma non capisco bene di cosa ho bisogno e come devo costruirlo/montarlo.
http://www.vespaonline.com/tecnica/tecnica-generale-telai-piccoli-et3-pk-special-ecc-ecc/73044-regolatore-di-tensione-salva-lampadine-fai-da-te.html
2  International / Generale / Re: Problema voltaggio per led su Vespa 1976 on: June 11, 2013, 04:54:40 pm
Grazie mille per la risposta molto rapida! smiley-wink
Quindi se ho capito bene una delle possibilità sarebbe quella di comprare una resistenza di 15W e 10ohm? nel senso che la attaccherei semplicemente all'uscita positiva?
Questa funzionerebbe ad esempio? http://www.ebay.it/itm/Ceramic-resistors-15-ohm-10W-15R-resistenze-in-cassa-ceramica-5pcs-/400461054445?pt=Componenti_elettronici_passivi&hash=item5d3d56c1ed&_uhb=1#ht_500wt_974

Il regolatore di tensione che ho comprato non serve a nulla? smiley-wink http://shop.boxtec.ch/l7805cv-voltage-regulator-l7805cv-p-40362.html

Grazie mille ancora!
3  Using Arduino / Motors, Mechanics, and Power / Re: Voltage regulator for Vespa Primavera 1976 on: June 11, 2013, 04:31:02 pm
Yes i think it works with some kinda of dynamo.
Maybe with this is better: http://www.seigiorni.it/tecnica/schemi_elettrici/doc.elettrici/vn1-2vl1-ita.gif
Sorry i really don't know nothing about motors smiley But thank you for the fast reply!
4  International / Generale / Problema voltaggio per led su Vespa 1976 on: June 11, 2013, 04:09:51 pm
Ciao a tutti!
Mi sto cimentando nell'impresa di sostituire le luci della mia Vespa 125 primavera del 1976 con dei led. Il mio problema è che il voltaggio non è regolare quindi immagino di dover costruire una sorta di regolatore di tensione. Il voltaggio della vespa, che è generato direttamente dal motore quando è acceso (nessuna batteria, è un modello del 1976), dovrebbe essere di 6V ma ho provato ad attaccare un led (calcolando e aggiungendo dovute resistenze) e il risultato è stato il seguente: accendendo la vespa e si accende il led, dò gas e il led diventa più luminoso, ma quando comincio a partire e a inserire la seconda marcia il led brucia dopo 2 metri.
Qualcuno può aiutarmi? Anche perché anche con Arduino mi si pone davanti questo problema di abbassare il voltaggio e non so davvero come fare smiley

Ps. ho comprato un "regolatore" così: http://shop.boxtec.ch/l7805cv-voltage-regulator-l7805cv-p-40362.html
Potrebbe essere utile?

Ecco lo schema elettrico della mia vespa:
http://img524.imageshack.us/img524/65/schemaelettricoprimaverlt5.jpg

Grazie mille per l'aiuto! Spero possiate aiutarmi!
Nick
5  Using Arduino / Motors, Mechanics, and Power / Voltage regulator for Vespa Primavera 1976 on: June 11, 2013, 03:52:26 pm
Hello everybody!
I have an old Vespa Primavera 125 (1976) and i would like to connect leds to the alimentation. My problem is that the voltage isn't regular, because it doesn't have a battery but it works with the motor. So i think i should build a voltage regulator but i don't know how. Someone can The voltage should be 6V, so i tried to connect a led with the resistor; it worked for a bit but then it burned. So i think i need a Voltage Resistor for higher voltage than 6 V.

This is the schematics of my Vespa
http://img524.imageshack.us/img524/65/schemaelettricoprimaverlt5.jpg

Thank you for the help and sorry for my bad english smiley-wink
6  Using Arduino / LEDs and Multiplexing / Re: led RGB strange colors on: January 19, 2013, 10:39:32 am
Hello,
I resolved my problem! I don't know why but my values were inverted (0 was 255), so i mapped my color variables.
Thanks anyway smiley-wink
7  Using Arduino / LEDs and Multiplexing / [RESOLVED] led RGB strange colors on: January 19, 2013, 10:14:00 am
Hello,

I'm trying to use my common anode rgb led but i don't understand how the mixing colors work.
RGB led: R = 1.9V , G = 3.0V , B = 3.0V; 20mA.
I calculated the resistor (5V - 1.9V) / 20mA = 150 ohm for Red
                                 (5V - 3.0V) / 20mA = 100 ohm for Green and Blue.

I tried many colors but the don't seems right:
(i tried with Blue)

analogWrite(red, 0);
analogWrite(green, 0);
analogWrite(blue, 255);

But the color was yellow. Is it right? For me is really strange smiley
I also tried to work with a RGB color picker online:
i tried a pink rgb color (235, 47, 166) but the result was a blue-green color.

Please help! smiley Thank you!



8  Using Arduino / General Electronics / Re: Problem: burning leds in series on: January 17, 2013, 08:24:41 pm
Thank you for the scheme! Are they leds in parallel right? I use the single led like if it was the only one (right?).
6V - 1.8V = 4.2V / 20 mA = 210 ohm. And with this method my leds won't burn?

But you know why my first method did work only for a few minutes and then burned? I need to know smiley-wink

Thanks so much
9  Using Arduino / General Electronics / Re: Problem: burning leds in series on: January 17, 2013, 07:36:52 pm
Sorry, my bad smiley-wink

3 leds (6V - 1.8V - 1.8V - 1.8V) = 0.6V / 20 mA = 30 ohm.

But i used a 100 ohm resistor for being sure, and my leds burned. Isn't it strange?

Thank you!
10  Using Arduino / General Electronics / Problem: burning leds in series on: January 17, 2013, 06:34:30 pm
Hello,

Yesterday i was trying to build my first led (in series) board. I used 3 red leds (1.8V, 20 mA) and 4 AAA battery (= 6V).
I calculated the right resistor ( 6V - 1.8V - 1.8V ) / 2 mA = 30 ohm; i should use a 47 ohm resistor but i used a 100 ohm resistor on the positive wire.
I tried the battery on my board and the three leds lighted up, but after 3 minutes suddently the leds turned off.
I checked the current with my multimeter (was 6V) and tried to light a single led with arduino but it didn't worked.
Someone can explain my error? Because i don't understand why using a bigger resistor it can be happen.
How can i correct my board smiley-wink

Thank you so much!
11  Using Arduino / Project Guidance / Re: How to connect Arduino Uno to 25 rgb leds? on: January 16, 2013, 05:35:17 am
Hello, thanks again! I ordered the shift registers and the Common anode rgb leds, so in a few days i will begin my project! smiley-wink
@ grumpy_mike, i saw the arduino clear bit but i can't understand hit it works, can you please make an example? Is it right my scheme i uploaded?

Thank you for the help!!!
12  Using Arduino / Project Guidance / Re: How to connect Arduino Uno to 25 rgb leds? on: January 13, 2013, 07:09:57 pm
Thank you smiley-wink My project is a 25 rgb leds single color changer with a random function.
I tried to build a scheme (based on this http://www.elcojacobs.com/wp-content/uploads/2012/08/shiftpwm_74hc595_RGB.png). Practically the 74HC595 shift works with a "data" connection (in 1st pin, out last pin), but in the code how can i control the single led?
I attached the scheme i build (only two shifts), but i think the "shift" has less pin that it should have.

Thank you for the big help!
13  Using Arduino / Project Guidance / Re: How to connect Arduino Uno to 25 rgb leds? on: January 13, 2013, 02:17:01 pm
Thank you again for the answers!
So, i think i will use common anode rgb led.
I'm looking for the TLC5940 and others but i can't find them in my store. I only found the Shift Register 8-Bit (74HC595) and the Shift Register 8-Bit High-Power (TPIC6B595).
I'm reading this article http://www.elcojacobs.com/using-shiftpwm-to-control-rgb-leds-with-arduino/
If i use 10x 74HC595 i will need (per every rgb led): 1x 150ohm resistor (red) and 2x 100ohm resistor (green and red). Is it right?
I also read that with many shift register, my project could become slow (?)

I will post the schematic that i'm trying to make for my project smiley-wink

Thanks everybody! You are great!
14  Using Arduino / Project Guidance / Re: How to connect Arduino Uno to 25 rgb leds? on: January 12, 2013, 06:52:25 pm
Thank you all for the answers! You were very fast smiley
I saw that i can use some multiplexers (PaulS) or a shift register (lightUp). Which one is the best solution? And how many multiplexers or shift register i need to light the 25 rgb leds?
Thank you so much! I hope my questions aren't so stupid! smiley-wink
15  Using Arduino / Project Guidance / How to connect Arduino Uno to 25 rgb leds? on: January 12, 2013, 06:03:19 pm
Hi, i'm a newby with Arduino and i have a technical problem: i need to connect an Arduino Uno to 25 rgb leds but i don't know how.
I've read that should use a 3 - 8 decoder (is it right?), but if a single rgb led need 4 pins to work, how can i connect the other 24 in 11 pins?
And how can i change the color of a single rgb led?

Thank you everybody! And sorry for my bad english smiley
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