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1  Using Arduino / General Electronics / Re: Question about transistors on: Today at 09:59:31 am
sounds like an h-bridge..


no that's not a scehamtic! that's a picture with lines on it smiley
2  Using Arduino / General Electronics / Re: Resistor required for PN2222A transistor base? Diode also? on: Today at 09:46:17 am
http://everycircuit.com/circuit/6035632115679232/transistor-parraral-loading

the circuit i designed using 2n2222's should work fine...

(Uses chrome in order to view the circuit sorry)

or view the attached image.


I lowered it to 20ohm per transistor and 1 ohm allowing a 2watt 1ohm resistor to be used - the diode to supress any voltage spikes from the motor, but obviously you can increase the load on each providing you do it to all balancing them...
3  Using Arduino / General Electronics / Re: hc-05 model without a breakout board on: Today at 03:24:44 am
http://www.ebay.com.au/itm/10pcs-DIY-Prototype-PCB-Universal-Experiment-Matrix-Circuit-Proto-Board-4x6cm-/111169619180?pt=AU_B_I_Electrical_Test_Equipment&hash=item19e239c4ec

 just insulate with tape or something to prevent the bluetooth pins shorting.. and simply solder or try to the module to the perboard then solder header pins or wires, just be careful not to short anything when aligning up, i'm waiting on a small FM module to try this very same technique....  if it clearly does not line up, use wires and solder them to the perfboard turning it into a odd looking spider.
4  Using Arduino / General Electronics / Re: Resistor required for PN2222A transistor base? Diode also? on: Today at 03:16:18 am
if you have a few 2n2222's you could get creative and wire 4 or 5 up to give you a nice distributed 1amp of power...
5  Community / Bar Sport / Arduino Brain Bot. on: September 30, 2014, 12:15:57 pm
I was thinking wouldn't it be cool if there was some kind project involving old and new technology in one...

Let's use i2c or uart etc.

Entry 1, arduino uno, it has 2 hardware ports to allow communication with 2 other boards, a protocol is developed, send it a comnand to switch on or read a pin, use an ethernet shield,  give the protcol thr ability to send basic packets over wifi, ir sensors etc etc. Status pin 3 set pin 3 ..

The return data is fowarded on.
Entry2, arduino due, does more etc

Each board is plugged/attached so they are all serially linked.

Entry 3, yun, wifi access scripting more poweful data.

All these boards shift data around they all allow each other to share sensors read data.

Uno could now command yun to send over wifi, if fail try the ethernet shield

How long before boards require icsp and reprogram older hardware and software turns on software.....
6  Using Arduino / General Electronics / Re: Noob Question about Transistors on: September 30, 2014, 01:13:10 am
Depends on the transistor configuration. . You sound like you want to sink current in which case on an npn yes the collector needs to match what's on your base voltage..

Sinking can be done with 0.7v or higher 300ohms should put that transistor into high conduction from a 5v source eg arduino.
7  Using Arduino / Programming Questions / Re: DNA computing? on: September 29, 2014, 11:47:07 pm
https://www.nanoporetech.com/technology/the-minion-device-a-miniaturised-sensing-system/the-minion-device-a-miniaturised-sensing-system
8  Using Arduino / Project Guidance / Re: 5W or 10W Led Driver for RGB on: September 29, 2014, 08:10:46 pm
To drive that all you need is 3pwm ports... each one to it's own rgb.

(But what's on the other side?.. ) hopefully each transistor turns on via it's base and draws a small amount of current < 40ma)
9  Community / Bar Sport / Re: Poll. Which are the safe frequencies? on: September 29, 2014, 08:01:59 pm
Well most people don't stand under voltage lines...

So if it's not wavelength that makes it dangerous then what does? I don't see how something oscillating emitting rf can be made more dangerous by shifting the frequency,  the universe has shown us darkness but in reality the sky is a light in the night, just the  wavelengths have shifted down into the radiowaves due to the expansion of the universe we now see distant light waves on old CRT analog tv channels more so now due to the terrestrial analog signals shut off...





10  Community / Bar Sport / Poll. Which are the safe frequencies? on: September 29, 2014, 07:20:06 pm
And since there is no poll smiley-roll (for us mere mortals)


Going by the assumption,  shorter the wave length the more energy intensive....

Anything under the visible range- eg all the radio waves, excluding microwave and certaily everything else like sunlight (skin cancer) and deem anything in the cm's to meters safe?

Agree or Disagree?


11  Community / Bar Sport / Re: Where can I get expert advice on a 4G mobile broadband problem? on: September 29, 2014, 07:09:10 pm
What's your mobile phone signal like when placed next to the modem, I presume it will also use 3G?
12  Using Arduino / General Electronics / Re: Avantages of proper bench power supply vs. alternatives? on: September 29, 2014, 06:06:11 am
Hi, before you do anything.
What is the load, the wire cutter will consume energy, how much?

Current limit is essential, if you can get it, IT PROTECTS THINGS, even though some might think they are annoying.

Quote
And current limiting can be annoying on workbench power supplies,



Tom................... smiley

One day you'll get complacent and forget while everyone else relies on the circuit...
13  Using Arduino / General Electronics / Re: Avantages of proper bench power supply vs. alternatives? on: September 29, 2014, 03:37:17 am
Cool, and no, current limiting is important....  - eg if you wanted to protect a laser diode, a bench supply would be perfect for quickly testing and diagnosing faults, with el cheapo method (unless you buy current regulated one) it's trickier using resistors or a current limiting circuit..

Buy whatever suits you, i'm just saying try not to rely on current limiting or you'll eventually blow something smiley
14  Using Arduino / General Electronics / Re: Help with small electronics project on: September 29, 2014, 01:20:41 am
Well, if you thought about how a fuse blows you could argue under certain conditions (but this does not relate to this) conditions.

A fuse blows when a certain amount of current is reached, not voltage....  But, one could argue Current is proportional to Voltage, you're simply not going to be able to get 1amp or 2amp current flowing if all you're using is a couple of volts, unless that voltage is pumped up you're not going to get significant amount of current...


So you could say a fuse protects against voltage, because without voltage you wont have the current  smiley-lol
15  Using Arduino / General Electronics / Re: Avantages of proper bench power supply vs. alternatives? on: September 29, 2014, 01:09:11 am
I've not needed one, I bought a stack of switching voltage regulators, if i require more than 5amps (more than a laptop switch mode charger) I'd opt for a computer power supply for about 30 bucks.

And current limiting can be annoying on workbench power supplies, you may have it set to 100ma to protect something but next time you plug something in, you look directly at voltage set it to 5v or whatever, and then connect the device, the 5v reading drops voltage! duh! current limiting readjust,  So i have a feeling if i used a labbench not the method you propose, a screwdriver on a pot on these switching buck regs, i'd forever be adjust the damn current... So i prefer to not bother with current regulation, let the device pull whatever it requires..  rely on the circuit not external devices to limit it's own current then current regulation can just be set at a fixed value.
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