Can anyone explain to me, why, when I use my lab psu instead of a battery, some devices just act completely bonkers? One of them was a device with blinking lights and stuff, and it would just go into shutdown mode after a sec or so.
[QUOTE=SEKCobra;41197791]Can anyone explain to me, why, when I use my lab psu instead of a battery, some devices just act completely bonkers? One of them was a device with blinking lights and stuff, and it would just go into shutdown mode after a sec or so.[/QUOTE]
Is your psu supplying enough current (if it has one is the current limit wound down?)?
[QUOTE=metallics;41198032]Is your psu supplying enough current (if it has one is the current limit wound down?)?[/QUOTE]
Actually, jog my memory on battery voltages, could it be that they are actually a bit above their rated voltage when full? Because I just seemed to remember that that's how it is.
[QUOTE=SEKCobra;41198104]Actually, jog my memory on battery voltages, could it be that they are actually a bit above their rated voltage when full? Because I just seemed to remember that that's how it is.[/QUOTE]
Yes they will usually be a bit above with a full charge, although this should not matter unless you have a really really sensitive circuit.
[QUOTE=Chryseus;41198126]Yes they will usually be a bit above with a full charge, although this should not matter unless you have a really really sensitive circuit.[/QUOTE]
Well I'd assume the chip probably shuts it off when "empty". At least that would explain it.
[QUOTE=SEKCobra;41198135]Well I'd assume the chip probably shuts it off when "empty". At least that would explain it.[/QUOTE]
What chip ? I thought you said you was having problem with your power supply?
The one in the device I was powering.
Could be noise. If it's a SMPS it'll probably kick out a fair bit of noise, especially if it's a cheap one.
The coil worked fine when I plugged it in. GAve it a new coat of paint. [del]I wonder if I can drive my xeon arc bulb with this.[/del] NOPE: I need a LOT more power.
[IMG]http://i11.photobucket.com/albums/a166/ballsandy/CGS_0027.jpg[/IMG]
The thermal printer guts down to a nice device that just needs 24V and some sort of input. Epson makes unobtanium modules that let you interface with anything from serial to 802.11b. I have the RS-422 module however and own nothing to interface that with. :/
[IMG]http://i11.photobucket.com/albums/a166/ballsandy/CGS_0026.jpg[/IMG]
The generator is the real prize. It needed new fuel lines, several o-rings, the tank had to be descaled and flushed and the whole thing degreased. After it was put back together it started with just half a pull. Going to use it this weekend with a projector and laserdisc player to watch horror movies out int he woods with friends.
[IMG]http://i11.photobucket.com/albums/a166/ballsandy/CGS_0028.jpg[/IMG]
Edited: Awww. I think the regulator in the generator gave out.
Hey guys, I have a question.
Im trying to rig up a solar charger I can use for my phone. This is what Ive come up with so far:
[IMG]http://i.imgbox.com/abfbuvIF.png [/IMG]
Will this work?
I took a basic electronics class two semesters ago, but I forgot most of it, so laymans terms if possible.
I've only taken basic digital electronics. Recently I've found myself obsessed with FM radios. Where can I learn more so I can learn how to build an FM transmitter?
Check with your authorities that it is legal to transmit on those frequencies.
[QUOTE=Birdman101;41220498]Hey guys, I have a question.
Im trying to rig up a solar charger I can use for my phone. This is what Ive come up with so far:
[IMG]http://i.imgbox.com/abfbuvIF.png [/IMG]
Will this work?
I took a basic electronics class two semesters ago, but I forgot most of it, so laymans terms if possible.[/QUOTE]
You've got the right basic idea but as it is it would not work. For starters, solar panels don't output a constant voltage so simply hooking it up to a battery would destroy the solar cell because the battery would be discharging through the cell. You need to connect a boost converter to step up the voltage from the panel to a constant output which can either charge the phone directly or charge a battery.
I've never worked with solar panels so I'm not the person to help you with this though.
[QUOTE=Birdman101;41220498]
Will this work?[/QUOTE]
No, the first problem being solar panels are a very non-ideal voltage source which means the output voltage will drop the more current you try to draw from it, in practice this means that you only get maximum power at a specific current draw which is known as the Maximum Power Point (MPP).
[img]http://www.mpoweruk.com/images/pv_VI.gif[/img]
A more serious problem is the amount of current the cell will output, I'd make a very rough estimate of 25mA to 50mA under very bright lighting conditions, assuming your battery pack has a capacity of 800mAh this will take around 18 to 20 hours to charge at 50mA, so the idea is not really feasible.
Then you have the problem of getting the current through the battery, in general you want a bare minimum charge voltage to be 30% or more higher than the maximum cell voltage, then you have the charge topology to consider which in this case would almost certainly have to be done by a constant current source circuit.
Oh and the 5V regulator needs at least a 2V overhead unless you use a decent LDO type.
[QUOTE=Agent766;41220770]I've only taken basic digital electronics. Recently I've found myself obsessed with FM radios. Where can I learn more so I can learn how to build an FM transmitter?[/QUOTE]
There are plenty of simple FM transmitter circuits floating around the net, I'll see if I can find you a decent book in my collection.
Here you go [url]http://www.mediafire.com/?enfd5phah5fyn69[/url]
[QUOTE=SEKCobra;41221315]Check with your authorities that it is legal to transmit on those frequencies.[/QUOTE]
It's never legal to transmit on the FM radio band unless you have a license, and those cost a huge amount.
However low power transmission is ignored, if it can't be picked up outside a 20-50 meter radius your good.
[img]https://dl.dropboxusercontent.com/u/59112523/2013-06-28%2014.29.49%20-%20Copy.jpg[/img]
Made a test lead hanger by cutting up and mutilating an old [url="http://www.ikea.com/se/sv/catalog/products/30200253/"]ikea SIGNUM cable management tray[/url]
[QUOTE=Agent766;41220770]I've only taken basic digital electronics. Recently I've found myself obsessed with FM radios. Where can I learn more so I can learn how to build an FM transmitter?[/QUOTE]
I'd recommend using [URL="http://www.radio-locator.com/"]http://www.radio-locator.com/[/URL], its a convenient tool for checking for free bands, but nothing beats checking on a car radio.
Also, give [URL="http://www.talkingelectronics.com/te_interactive_index.html"]Talking Electronics[/URL] a shot, they're a wealth of info. I'd also recommend checking up on the details of inductors/reactance/inductance/etc this will help when it comes to building some Colpitts/Hartley/etc oscillators. If you're more comfortable with digital circuits, I might recommend looking into digitally controlled PLLs, they won't provide the nitty-grittiness of inductor/capacitor based oscillators but they are a great transition IMHO from digital to analog.
Just got 82% on my electronics module, fuck yeah! Thanks for your help with any questions over the last year guys.
[QUOTE=chipset;41222691]You've got the right basic idea but as it is it would not work. For starters, solar panels don't output a constant voltage so simply hooking it up to a battery would destroy the solar cell because the battery would be discharging through the cell. You need to connect a boost converter to step up the voltage from the panel to a constant output which can either charge the phone directly or charge a battery.
I've never worked with solar panels so I'm not the person to help you with this though.[/QUOTE]
Also charging typical rechargeable AA batteries are a [I]BITCH[/I], it's easier to charge lead acid batteries (think car and scooter batteries) or Lithium ion batteries [B]BUT[/B] with li-ion batteries you must incorporate failsafes from overcharging7overdischarging them.
Or a simple & cheap charging IC.
[QUOTE=Van-man;41224129]Also charging typical rechargeable AA batteries are a [I]BITCH[/I], it's easier to charge lead acid batteries (think car and scooter batteries) or Lithium ion batteries [B]BUT[/B] with li-ion batteries you must incorporate failsafes from overcharging7overdischarging them.
Or a simple & cheap charging IC.[/QUOTE]
Yeah lead acid is the way to go if you want easy charge, I've had a pretty good experience charging NiCd batteries as well.
[img]https://dl.dropboxusercontent.com/u/59112523/2013-06-28%2019.58.40.jpg[/img]
Made an MDF base plate for my rasp pi.
MDF is a surprisingly pleasant material to work with, it behaves more like a plastic or a very soft metal than wood. I even find myself using a scribe to mark it rather than a pencil more often than not.
I had some of this 6mm thick stuff left over after a shelf project and figured I'd make something simple just to keep it off the bench. The screws are regular machine screws so I had to sink the heads into the material to get a flat bottom.
Can a Raspberry Pi do basic vision processing? I want to make a device that uses a webcam to sync my car's blinker with the person's in front of me.
[QUOTE=Agent766;41228388]Can a Raspberry Pi do basic vision processing? I want to make a device that uses a webcam to sync my car's blinker with the person's in front of me.[/QUOTE]
You're in luck actually, they recently released the community supported camera module along with OpenCV: [URL="http://thinkrpi.wordpress.com/2013/05/22/opencv-and-camera-board-csi/"]http://thinkrpi.wordpress.com/2013/05/22/opencv-and-camera-board-csi/[/URL]
[QUOTE=Agent766;41228388]Can a Raspberry Pi do basic vision processing? I want to make a device that uses a webcam to [B]sync my car's blinker with the person's in front of me[/B].[/QUOTE]
that's some scary level of OCD
[img]http://imgs.xkcd.com/comics/turn_signals.png[/img]
I shall call it the Blinker Syncer.
[IMG]http://i.imgur.com/KUUcCGQ.jpg[/IMG]
Just made it.
Share your wire spool storage!
[QUOTE=chipset;41242954]
Just made it.
Share your wire spool storage![/QUOTE]
That's a pretty neat idea.
Would be good if you wind lots of coils and stuff.
Yeh, im thinking of doing somthing like this for my room, once the walls exist and the benches are in ect
Planning on building a coil winding system into it because i plan to do alot of teslacoils / transformers ^^
I need spools so I can then be persuaded to strip down and wind up the 50 conductors that make up the telephone trunk cable I've been slowly chipping away at.
[QUOTE=pentium;41248291]I need spools so I can then be persuaded to strip down and wind up the 50 conductors that make up the telephone trunk cable I've been slowly chipping away at.[/QUOTE]
That is often the cheapest method of getting wire, buying large multi core cable, irritating as hell however...
So, I dug up this 5 watt fm transmitter I have, and tested it. The thing is, it doesn't emit a carrier on one frequency, however, it fucks up the whole 3meter band to noise, I can't hear any other radiostation any more when I turn this thing on, and I have absolutely no clue what's wrong with it.
Ideas?
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