Show Posts
Pages: [1] 2 3
1  Using Arduino / General Electronics / Re: Desoldering a potentiometer on: November 26, 2012, 05:07:10 pm
Hey guys!

Thank you all so much for your generous information! I've been able to snip off the leads of the rotary encoder (after looking at it, yea, it is one.. smiley-grin) and desolder the remaining pins - thankfully without breaking any pads. Now that I have the part broken out, I'm not sure what kind of rotary encoder this is. Would I be able to use any encoder that's similar in size and amount of pins? Or are there different versions of encoders? Sorry about the confusion, first time working with encoders.

Greets
Philipp
2  Using Arduino / General Electronics / [Updated] Desoldering a roatry encoder on: November 25, 2012, 05:04:39 pm
Hey Guys!
I'm trying to desolder the following potentiometer:



I need to preserve both the PCB and the potentiometer while doing so. Unfortunately, I'm pretty much out of ideas as to how to approach this.. I tried using a desoldering pump to no extent (wasn't able to suck away enough solder to loosen the connections). I tried heatgunning it, but for some reason (temp. is about 300°C -> 572°F) the solder wouldn't even begin to melt. I was thinking about buying some solder wick tomorrow, but I'm not sure whether it'll be able to remove enough solder or just end up like the desoldering pump did.

Apart from that, do you guys know of any other method I could try to remove that piece?

Greets
Philipp

[Update]
http://arduino.cc/forum/index.php/topic,134202.msg1010585.html#msg1010585
3  Using Arduino / General Electronics / Re: Looking for the right Optocoupler on: November 24, 2011, 08:39:37 am
Hey guys!
Thank you all again for the great advice! I've now ordered several opto-couplers, since unfortunately I was unable find any of the ones you specified in german online-shops...

Here's the one's I got:

http://www.pollin.de/shop/downloads/D120636D.PDF
http://www.pollin.de/shop/downloads/D120629D.PDF
http://www.produktinfo.conrad.com/datenblaetter/175000-199999/187038-da-01-en-PC817.pdf
http://www.produktinfo.conrad.com/datenblaetter/175000-199999/183721-da-01-en-Optocoupler_4N27.pdf
http://www.produktinfo.conrad.com/datenblaetter/150000-174999/153533-da-01-en-Optocoupler_ILD74.pdf

Would any of them actually be suited for the job? I've read through their datasheets, and from what I understood they *usually* (doesn't apply to all of them) take around 1.45V of forward voltage on the LED, around 25mA. So I should base my resistor calculations on the LED-side on those values, right?

I seem to have some problems "decoding" the Collector's ratings though.. Essentially I've read through the definitions of all of the values, but unfortunately, that doesn't make me any smarter.. It'd be awesome if you could tell me what values *exactly* I have to look for.

To remind you: LED side input is 24VDC (after rectifying it) at 2A max., Arduino-side transistor output is the regular 5V.

Greets,
Philipp
4  Using Arduino / General Electronics / Re: Looking for the right Optocoupler on: November 19, 2011, 10:11:30 am
I thought about it as well, but not for me, no. The whole box is in such a good condition, it'd be a shame to gut the whole mechanism.. it really is a masterpiece of engineering work and a great reminiscence of a long gone time. Really, there wasn't a single wire I had to replace, not a single switch, practically no rust, little dirt, etc.

It'd just be too bad to lose all that mechanical mastery!

@terryking228: That IC assortment is awesome! And yea, you're right.. by the time the weekend has finally come and I find myself being able to figure out how I'll go about actually building a project, I always have to wait some time before I can then actually start building.. It sucks to not be able to put your toughts into practice right away smiley-grin
5  Using Arduino / General Electronics / Re: Looking for the right Optocoupler on: November 19, 2011, 06:29:28 am
Wow, I guess reddit doesn't care too much about Safari.. will use Imageshack again next time smiley-wink
6  Using Arduino / General Electronics / Re: Looking for the right Optocoupler on: November 19, 2011, 05:23:09 am
These look really nice! I just found out that there's a german version of Digi-Key as well smiley-grin Before it would've been quite annoying having to wait a couple weeks for your parts to ship from the US, so I generaly avoided any US retailers..

@GoForSmoke: Thanks a lot for these links as well! I'll be sure to check them out.

@Graynomad:
I've had the idea for a while now, but unfortunately it's quite hard to find an original Wallbox/Jukebox over here in germany at a reasonable price. I bought the box for around $200 and I must say, for that price it was a steal! The box was alomst entirely in original condition, except for the lamps, coin slot and the "Make any selection" plates, which had been replaced by cardboard with german text on them. Oh yea, there also is a german slug rejector in there (wouldn't make sense to only allow USD in Germany, huh smiley-grin)

I've replaced all the parts and quickly hacked together a power plug for a 24VAC transformer I found on eBay. The big surprise came when I first hooked everything up.. it went pretty much perfect on the first try. There's a couple of adjusting screws you'll have to take care of, because obviously they'll have losened over time, but otherwise it worked just fine smiley-grin

If anyone's interested in a couple pictures of the rebuild-process, here you go smiley-wink

http://imgur.com/a/AMbNM (Note that obviously all the chrome parts are missing there smiley-grin They're back on now)
7  Using Arduino / General Electronics / Re: Looking for the right Optocoupler on: November 18, 2011, 01:05:49 pm
Hi Rob!
Thank you so much for helping me out this detailed smiley-grin

Apparently so, yes. From the looks of it I can't seem to find anything more complicated to the mechanism than this - considering it's a consumer machine from the late 50's, this might even hold true.

Since it's a cheap part, I'll additionally use the rectifier bridge. If the Schmitt-Trigger is needed, I'll add one, but for now I'll try with as few parts as possible to not make it too complicated for me.. been a while since I've fiddled with electronics smiley-grin

Yea, that's pretty much what I was planning to do. Then once I have the correct sequences, it'll just be a matter of deciding on which device to decode them. I'll probably do it on the arduino, since I'm not too sure about sending time-critical data via bluetooth, although after some tests it shouldn't really matter.

As for the opto-coupler itself, I've been looking at this one:

http://www.produktinfo.conrad.com/datenblaetter/175000-199999/187038-da-01-en-PC817.pdf

Though I'm not sure which ratings to use to calculate my resistor values, etc.. Reading these data sheets is indeed quite hard.

Greets,
Philipp
8  Using Arduino / General Electronics / Re: Looking for the right Optocoupler on: November 18, 2011, 11:04:56 am
Tbh, I have no Idea.. my multimeter isn't accurate enough to measure the pulses in time, so my best chance of finding out when exactly the pulses fire is by hooking it up to my arduino constantly checking its input.

It basically works like this:
There's letters (A-V, omitting some like O or I) and numbers (0-8), making a total of 160 possible selections. When a combination of Letter+Number has been pressed, a motor moves a contact arm first over numbers 1-8. The contacts are wired in series, so if I'd press 5, pulses would be fired when the contact arm went over 1,2,3,4 and 5. Same thing then happens again for the letters, with a longer pause in between to detect the transition from number to letter.

Documentation on these machines (especially on the parts you usually wouldn't have to worry about when hooking it up to a regular jukebox) is quite hard to find, so unfortunately I haven't yet found anything about the pulse timing..

Greets,
Philipp
9  Using Arduino / General Electronics / Re: Looking for the right Optocoupler on: November 18, 2011, 10:53:27 am
Perfect! Yes, knowing that there IS a signal is enough for my project. Essentially, I want to check if there's a signal (haven't decided whether to use interrupts or loops yet) and if so, check the time between the current and next signal. There's an exact combination of signals for each title selection you can make on the box. I'll then send these via bluetooth to my PC/Laptop/etc. to play an according tune smiley-wink

I've just read about diode bridges/bridge rectifiers. Would it also be an option to convert AC to DC using a diode bridge like this one (http://en.wikipedia.org/wiki/File:Diode_bridge_alt_1.svg) and then run the output DC through a regular opto-coupler?

Greets,
Philipp
10  Using Arduino / General Electronics / Re: Looking for the right Optocoupler on: November 18, 2011, 10:35:03 am
Hey guys!
First of all, thanks a lot for your answers!

@Grumpy_Mike: No, it's not a power supply, it's the signal line coming from a Seeburg Wallbox (http://www.flippers.com/images/Prop-Seeburg-wallbox.jpg)

I've just been to my local electronics shop and they've told me that an opto-coupler won't work at all for this.. kinda strange.. The man said something along the lines that

a) There's no opto-coupler that allows AC on it's LED (makes sense now that I think about it..)
b) When simply using a resistor and diode to only get the +24V-0V part he said the signal would get "distorted", which has something to do with the waveform of the pulse.

Thing is.. can't I just "recalculate" the correct signal in my code? I know that the pulses are seperated by something between 300-500 milliseconds, so I guess that there should be enough room to detect a "gap" in the signal and make out where one pulse begins and ends, right?

Greets,
Philipp
11  Using Arduino / General Electronics / Looking for the right Optocoupler on: November 18, 2011, 03:31:05 am
Hi guys!
I'm trying to interface an old Seeburg Wallbox with my Arduino. The Wallbox sends a timed signal using 24VAC. My idea was to grab that signal using an optocoupler, since, to me, it seems like the best way to isolate the pure-AC circuit of the Wallbox from the pure-DC circuit of the arduino.

My question would be if anyone of you knows about an optocoupler that can handle 24VAC at 2A max. (I doubt it'll ever reach the 2A, but it'd be nice just to be safe) on the LED-side and the default 5VDC of the Arduino on the transistor side?

Thanks a lot in advance!
Philipp
12  Using Arduino / Programming Questions / Re: Modify item in queue using queue.peek()? on: May 01, 2011, 02:29:16 pm
Why don't you tell us what you're trying to do, not how you think you should do it?

Ok, here's the exact description:
I'm trying to stack up a queue of pins I want to pull HIGH one after another for a fixed period of time. So when the first pin's time's up, I want the next pin in the queue to go to HIGH and so forth.

A stack is only ever interested on what is on top of the stack, and a queue is only ever interested in what is at the head of the queue.

Well, all I'm interested in is the item at the head of the queue, but I want to modify it as well..

Greets,
Philipp
13  Using Arduino / Programming Questions / Re: Modify item in queue using queue.peek()? on: May 01, 2011, 02:17:59 pm
Oh, I'm sorry.. I meant to link to this file: http://arduino.cc/playground/Code/QueueArray

Basically I'm trying to queue up items of a structure:

Code:
typedef struct {
  int pin;
  int time;
  int counter;
} timedPin;

I'm trying to increment counter in every loop and check against time. If counter == time then the item is popped. (The pin setting was just testing).

Greets,
Philipp
14  Using Arduino / Programming Questions / Re: Modify item in queue using queue.peek()? on: May 01, 2011, 02:10:52 pm
Which doesn't work in my case because the pushed new value will land atop the queue when I need it to be at the beginning smiley-wink
15  Using Arduino / Programming Questions / Re: Modify item in queue using queue.peek()? on: May 01, 2011, 02:04:46 pm
But how would I go about retrieving the value peek() returns AND being able to modify it?
Pages: [1] 2 3