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121  Forum 2005-2010 (read only) / Interfacing / Re: Resistors & common anode 7-segment leds on: April 22, 2010, 08:12:30 am
Hi

I have some common anode 7segment displays. I want a few segments to just be on permanently.

So i connect the anode to 12v in this case, and then I ground the respective segment.

My questions:

I guess I need a resistor, but I would have to add it on on the cathode side, is that okay? (12v -> segment -> R -> GND)

And for the one digit I want to control with the arduino, do I write a HIGH to turn it off and LOW to turn it on? (I am not bothering with a shift register, its just one display and it gets it's own arduino anyway)

Thank you!

fubbi
122  Forum 2005-2010 (read only) / Interfacing / Re: Dimming an AC light on: December 04, 2008, 08:58:47 am
Quote
remember to place a big capacitor at the arduino output pin because the dimmer doesn't like the fast PWM pulses.

What kind of value are we talking about for the capacitor?

I am building a velleman dimmer controlled by a parallax ping. I am just about to connect them, I would really like to know this too before I hook it up.

fubbi
123  Forum 2005-2010 (read only) / Interfacing / Re: Solenoids and caps question on: October 04, 2009, 02:54:36 pm
makes sense! thank you!
124  Forum 2005-2010 (read only) / Interfacing / Solenoids and caps question on: October 04, 2009, 09:07:01 am
Hello

I am hooking up 4 solenoids, and I am trying to ad some big caps to
a. relieve the poor 500ma power supply
b. get more kick out of the solenoids

I have modified the tutorial solenoid pdf from the playground

http://fubbi.com/trans/solenoid.pdf

I got one cap connected, but when I want to connect the second i get a big spark.

I realize the first cap holds some current from my testing, but I still have a feeling I am doing something wrong...

thanks

fubbi
125  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 14, 2009, 06:39:39 am
okay, thank you for all the information

have a nice day

fubbi

126  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 14, 2009, 06:18:07 am
wait a minute

"The inductor is only going to be the size of a resistor at biggest."

I am confused. I thought I needed the entire circuit from your page?
127  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 14, 2009, 06:14:59 am
nope, those are shift registers. so I could keep the arduino pretty far away from them. so if I put the decoupler with the arduino on it's own it could work

thank you
128  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 14, 2009, 04:41:33 am
How do I know what size choke coil to use?

Thank you very much

by the way, this solution is no problem for my little boxes, there is room. I am however building a 64 tube controller on a custom A3 sized PCB. There is no more room there, can this solution be added further down the line somewhere? On the cable coming in or going out for example...

work in progress (!):

129  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 14, 2009, 04:06:10 am
That sounds just right!

Something like this?


130  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 13, 2009, 10:58:45 am
Oh

Actually I am using that resistor in the boxes with the minis. My mind wandered

fub
131  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 13, 2009, 10:32:36 am
Hi

The time the stall occurs is random. The duemilanove hangs, the mini reboots.

No resistors...

I am getting an increasing amount of random errors uploading to the mini so I think it is slowly getting fried.

fubbi
132  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 12, 2009, 12:19:59 pm
Hi

I am using the duemilanove now. Uploading to the minis in the boxes is a drag. So the parts aren't squeezed up like on the photo.

133  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 12, 2009, 11:52:43 am
@koalabog: nope, nothig is getting hot

@ retrolefty:

here's a quick and dirty of the duemilanove setup i have on my desk.
I realize the power supply is different in the boxes I built, but since the duemilanove hangs too (not with a bulb by the way) I presume the problem must be with the tubes.


134  Forum 2005-2010 (read only) / Interfacing / Re: fluorescent tubes - arduino stalls on: September 12, 2009, 10:59:58 am
Hello

The minis are in cases already and are powered by a 220v->5v 3A converter. It is the copper cage in the background of the image below.

The relay gets it's power from the 5v pin on the arduino.



here are the boxes


Thank you

fubbi
135  Forum 2005-2010 (read only) / Interfacing / fluorescent tubes - arduino stalls on: September 12, 2009, 08:49:18 am

Hello

I have built some controllers for fluorescent tubes.
The script is basically just writing high and low to the control pin.

The arduino stalls at random times. Sometimes straight away, sometimes after 10 minutes.

I have tried several minis as well as a duemilanove.

The duemilanove unfreezes when I pull the control pin, so there must be some kind of current rolling back through the circuit. Also, when I set the ons and offs to close, the stalls occur. Sometimes the minis even reboot. I am chasing the blinking on/off effect of the tubes. I am aware of fluorescent lights kicking back dirty when switching them on and off but I thought this circuit would be protecting the arduino.

I am using this schematic
http://www.arduino.cc/playground/uploads/Learning/relays.pdf


parts: I am about to build the master controller which will run 64 tubes, so I really need to understand whats bothering the circuit.

Thank you

Fubbi
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