[QUOTE=Chezburger;36208271]I mean what the fuck am I supposed to do with a ceramic capacitor which value has been worn of by the miraculous forces of time.[/QUOTE]
Meter.
I never got that LCD working, decided to give up on it for now
Just when I was wondering what I could do next, I had an idea. Of course, I've run into a bit of a problem!
Some particular device requires a 4.8v 600mAh battery pack. Good news is, I have said battery pack. Bad news is, I seem to have lost the charger. I do, however, have a charger which plugs into mains and outputs 11.6V and 160mA. First off, is this safe? I.E am I going to burn my house down if I try to charge this battery pack with the charger I have found?
Secondly, if it's not safe, do you have any other ideas for either charging the battery pack or supplying the device with the required power? Preferably without soldering, because my soldering iron has seemingly broken while I've been away
Cheers!
[QUOTE=Chryseus;36208887]Ddrl convinced me to go with the Toolcraft ST80-D instead of the fake but fairly well made Hakko FX-888 on dealextreme, I can't wait!
[img]http://i.imgur.com/N8fyD.png[/img]
Now I just need a bigger desk before it decides to collapse.[/QUOTE]
I have the 50w analog, same as ddrl. When you get it you've got to do a teardown and investigate the possibility of modding the 50w version to an 80w version. Sans digital control, of course.
[QUOTE=chipset;36210150]I have the 50w analog, same as ddrl. When you get it you've got to do a teardown and investigate the possibility of modding the 50w version to an 80w version. Sans digital control, of course.[/QUOTE]
Will do.
Anyone know where I can pick up a DE0 or DE0 Nano for a reasonable price without going through Terasic? Farnell carry the nano but they're not in stock yet and Adafruit have an extortionate markup. Halp.
Edit- Oh yeah, UK based. Would import a Chinese clone but I -always- get hit with spectacular import duties.
Alright fixed the power supply problem mentioned above. New problem!
I'm trying to bridge (what I think is) a radio signal from one pad to another on a PCB which usually is activated by a mechanical switch. I want to replace the switch so I can control this particular part of the PCB with an arduino. I figure a relay would work
So, I figured I only need a small low power relay to do the job. I was wondering if, therefore, I could connect my relay directly to a digital output pin from my arduino, and cover it with a protection diode. The relay states it needs a minimum of 5v to switch, while my arduino pin kicks out ~4.8v. What's the chance this will switch correctly without the use of a transistor?
Relay in question: [url]http://www.maplin.co.uk/dpdt-1a-miniature-relay-37494[/url] (5v DC one)
Cheers
[QUOTE=Trumple;36223117]Alright fixed the power supply problem mentioned above. New problem!
I'm trying to bridge (what I think is) a radio signal from one pad to another on a PCB which usually is activated by a mechanical switch. I want to replace the switch so I can control this particular part of the PCB with an arduino. I figure a relay would work
So, I figured I only need a small low power relay to do the job. I was wondering if, therefore, I could connect my relay directly to a digital output pin from my arduino, and cover it with a protection diode. The relay states it needs a minimum of 5v to switch, while my arduino pin kicks out ~4.8v. What's the chance this will switch correctly without the use of a transistor?
Relay in question: [url]http://www.maplin.co.uk/dpdt-1a-miniature-relay-37494[/url] (5v DC one)
Cheers[/QUOTE]
It won't work, if it says 5v it's going to need 5v to operate reliably.
[QUOTE=Trumple;36223117]Alright fixed the power supply problem mentioned above. New problem!
I'm trying to bridge (what I think is) a radio signal from one pad to another on a PCB which usually is activated by a mechanical switch. I want to replace the switch so I can control this particular part of the PCB with an arduino. I figure a relay would work
So, I figured I only need a small low power relay to do the job. I was wondering if, therefore, I could connect my relay directly to a digital output pin from my arduino, and cover it with a protection diode. The relay states it needs a minimum of 5v to switch, while my arduino pin kicks out ~4.8v. What's the chance this will switch correctly without the use of a transistor?
Relay in question: [url]http://www.maplin.co.uk/dpdt-1a-miniature-relay-37494[/url] (5v DC one)
Cheers[/QUOTE]
Do you use a multimeter to measure the voltage? Unless you paid a lot of dough for you multimeter, its battery probably is low, causing it to show a slightly too low voltage.
Also, it should work regardless. The only danger ist that the relay will draw more than 40mA of current, which can possibly destroy the pin, although that never happened to me. But I've heard of other people destroying their pins that way.
Yeah this Multimeter I picked up from maplins for £9 today. It's surprisingly neat, the only thing it lacks is a continuity tester! But, I only really need it for basic stuff so I thought it would be alright
Alright well, I'll give it a shot directly on the pin, thanks!
[QUOTE=metallics;36223292]It won't work, if it says 5v it's going to need 5v to operate reliably.[/QUOTE]
Electronics is rarely about absolute accuracy, usually within 10% to 20% is perfectly acceptable, hell I've run 12V relays without problem down to 9V or less.
The website clearly says a 5V coil has a resistance of 180 ohm +-10%, so worst case that is 162 ohms, using Ohm's Law that works out to a holding current of 31mA so you should be able to drive it with an Arduino.
Also Maplin :vomit:
Yeah only reason I chose maplin was because it's close to me, I can reserve and pickup right up until 8pm
Works well for me because I'm impatient :v:
Pretty interesting project I'm doing, though. I'll let you all play with it when it's finished (you control it over the internet)
Thanks for the help
[QUOTE=Chryseus;36223564]Electronics is rarely about absolute accuracy, usually within 10% to 20% is perfectly acceptable, hell I've run 12V relays without problem down to 9V or less.
[/QUOTE]
Even when we deal with electrical tolerances of around 5%, say in installation wiring, the actual margin is (relatively) huge. It really is a discipline where "close enough" can work out better than "exact".
Blew the [url=http://www.vishay.com/docs/93711/50ria.pdf]50RIA20[/url] SCR (20A 200V thyristor) in my CDSW under normal operation/testing (20V discharge over nickel tab on a battery). Apparently, this thing puts out more than 1200 amps...?
Need a little help...should I buy some random 100A thyristor on eBay? Or should I put 4x IRFP2907 in parallel? I'd need to change up the triggering circuit a bit, of course.
[img]http://eagle.undo.it:8083/img/cdwelder_11_holycrap.jpg[/img]
The SCR was definitely holding the welder back from reaching its maximum power.
[QUOTE=DrLuke;36223393]Do you use a multimeter to measure the voltage? Unless you paid a lot of dough for you multimeter, its battery probably is low, causing it to show a slightly too low voltage.
Also, it should work regardless. The only danger ist that the relay will draw more than 40mA of current, which can possibly destroy the pin, although that never happened to me. But I've heard of other people destroying their pins that way.[/QUOTE]
DrLuke wins this round! The relay did infact work directly on the output of an arduino. It even worked on the 3.3v output pin!
Thanks for the help
[editline]7th June 2012[/editline]
Oh and Chryseus
[QUOTE=Trumple;36223536]Yeah this Multimeter I picked up from maplins for £9 today. It's surprisingly neat, the only thing it lacks is a continuity tester! But, I only really need it for basic stuff so I thought it would be alright
Alright well, I'll give it a shot directly on the pin, thanks![/QUOTE]
I know which one you're talking about (I work there) and it's horribly inaccurate. As for continuity the only thing it lacks is a buzzer.
Took apart a couple of TV's today! I didn't take pics of the actual TV's since that's rather boring IMHO, I did however take pics of the far more interesting tv tuners with the covers off.
(8MP images, open in new tab to enhance)
[t]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.26.38.jpg[/t]
[t]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.27.04.jpg[/t]
[t]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.28.20.jpg[/t]
[t]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.28.47.jpg[/t]
The top one has two pins labeled SDA and SCL, me and ddrl suspect it's an I2C controllable synthesizer. Definitely gonna have to look into that.
Now to spend hours desoldering anything interesting on the two mainboards.
[editline]7th June 2012[/editline]
Bonus: In the absence of a macro lens here's my setup:
[t]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.36.36.jpg[/t]
Magnifying glass attached in vice, place phone directly against magnifying glass.
Why is it that my DC motor works fine connected to the 5V out on the Arduino it works, but when I try to use analogWrite() it does nothing. I have even verified the circuit works too because I plugged the breadboard into the 5V out for testing. I thought that if I send 255 in analogWrite() to the correct pin that it would supply the 5V?
[QUOTE=toaster468;36239011]Why is it that my DC motor works fine connected to the 5V out on the Arduino it works, but when I try to use analogWrite() it does nothing. I have even verified the circuit works too because I plugged the breadboard into the 5V out for testing. I thought that if I send 255 in analogWrite() to the correct pin that it would supply the 5V?[/QUOTE]
It's because you can only source up to 40mA on the Arduino's pins, try connecting up a transistor to drive the motor.
Wow, I hooked it up to the analogread example and it is printing a number from 0 to 1023, never mind this wont work.
[editline]7th June 2012[/editline]
I don't get it, how does it work with the LED then?
[editline]7th June 2012[/editline]
[QUOTE=ddrl46;36239026]It's because you can only source up to 40mA on the Arduino's pins, try connecting up a transistor to drive the motor.[/QUOTE]
I was wondering why my post didn't merge. I didn't see your post sorry, can I have a schematic of that if you don't mind? I am kind of new to this.
Also, I only have one transistor and the last time I used it the thing got really hot for some reason.
[QUOTE=toaster468;36239052]Wow, I hooked it up to the analogread example and it is printing a number from 0 to 1023, never mind this wont work.
[editline]7th June 2012[/editline]
I don't get it, how does it work with the LED then?
[editline]7th June 2012[/editline]
I was wondering why my post didn't merge. I didn't see your post sorry, can I have a schematic of that if you don't mind? I am kind of new to this.
Also, I only have one transistor and the last time I used it the thing got really hot for some reason.[/QUOTE]
[img]http://i.imgur.com/2dKFm.png[/img]
[QUOTE=chipset;36238576]Took apart a couple of TV's today! I didn't take pics of the actual TV's since that's rather boring IMHO, I did however take pics of the far more interesting tv tuners with the covers off.
(8MP images, open in new tab to enhance)
The top one has two pins labeled SDA and SCL, me and ddrl suspect it's an I2C controllable synthesizer. Definitely gonna have to look into that.
Now to spend hours desoldering anything interesting on the two mainboards.
[editline]7th June 2012[/editline]
Bonus: In the absence of a macro lens here's my setup:
Magnifying glass attached in vice, place phone directly against magnifying glass.[/QUOTE]
Please do not post huge images in thumb tags, it makes chrome shit itself.
[QUOTE=Xera;36239236]Please do not post huge images in thumb tags, it makes chrome shit itself.[/QUOTE]
Okay I won't post them in thumb tags.
[img]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.26.38.jpg[/img]
[img]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.27.04.jpg[/img]
[img]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.28.20.jpg[/img]
[img]https://dl.dropbox.com/u/59112523/HFporn/2012-06-07%2023.28.47.jpg[/img]
Better?
Also does it matter what type of transistor? I only have 1 and it has some markings on it like:
[code]
2N
3904
H331
[/code]
[QUOTE=toaster468;36239271]Also does it matter what type of transistor? I only have 1 and it has some markings on it like:
[code]
2N
3904
H331
[/code][/QUOTE]
Yep that transistor should do, it's able to source up to 200mA.
[url=http://www.fairchildsemi.com/ds/2N%2F2N3904.pdf]Datasheet in case you need it[/url]
[QUOTE=toaster468;36239011]Why is it that my DC motor works fine connected to the 5V out on the Arduino it works, but when I try to use analogWrite() it does nothing. I have even verified the circuit works too because I plugged the breadboard into the 5V out for testing. I thought that if I send 255 in analogWrite() to the correct pin that it would supply the 5V?[/QUOTE]
YEAH I really wouldn't recommend driving a motor off one of the Arduino's pins. Use a transistor and PWM to control the speed of the motor, or build an appropriate motor driver circuit.
[QUOTE=Night-Eagle;36230636]Blew the [url=http://www.vishay.com/docs/93711/50ria.pdf]50RIA20[/url] SCR (20A 200V thyristor) in my CDSW under normal operation/testing (20V discharge over nickel tab on a battery). Apparently, this thing puts out more than 1200 amps...?
Need a little help...should I buy some random 100A thyristor on eBay? Or should I put 4x IRFP2907 in parallel? I'd need to change up the triggering circuit a bit, of course.
[img]http://eagle.undo.it:8083/img/cdwelder_11_holycrap.jpg[/img]
The SCR was definitely holding the welder back from reaching its maximum power.[/QUOTE]
I don't know how exactly your circuit looks like, but you should consider driving the transistor with a mosfetdriver IC. That way the transistor doesn't linger in the linear area that long, so your transistor won't dissipate a lot of power, causing it to melt/explode/whatever.
Could someone explain how a Tesla coil works?
[QUOTE=VistaPOWA;36244007]Could someone explain how a Tesla coil works?[/QUOTE]
It's using the principles of resonance. The secondary coil forms an LC circuit with the topload (the ball or toroid (donut shape) as the capacity), which has a natural frequency.
If you excite the coil at it's natrual frequency, the voltage inside it will swing higher and higher, until it's so high that it creates lightning.
A good analogy is a swingset, as it also relies on resonance: you have to push in just the right moment to make the swing go higher. If you push slower, or faster, you can't achieve as great a height.
DrLuke:
This is the trigger circuit I'm currently using to fulfill that purpose (thanks to [url=http://forum.allaboutcircuits.com/member.php?u=143625]jimkeith[/url]):
[img]http://eagle.undo.it:8083/img/cdwelder_12_trigger.png[/img]
Effectively dumping a 0.47uF ceramic capacitor at 12V into the SCR gate.
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