Show Posts
Pages: 1 ... 28 29 [30] 31 32 ... 190
436  Using Arduino / General Electronics / Re: battery charging... on: May 05, 2014, 03:59:28 am
I made a kick ass 5v liom battery charger with arduino safely enough..
Arduino will monitor current and voltage..
Question remains, even if it's 2v above, arduino would modify the voltage based on the battery's voltage after it settles..

In short  just by modifying voltage on the fly, it should allow you to control the charger's current?
437  Using Arduino / General Electronics / Re: battery charging... on: May 05, 2014, 12:53:13 am
What do you mean by 0.5v above its charge level?
How are you going to measure the charge level whilst charging?

Read my post.....?
438  Using Arduino / General Electronics / battery charging... on: May 04, 2014, 09:15:43 pm
To simplify thing.... I'm wondering if this method has been used before..

If say you charge a 4.2v lithium battery, if you kept a constant .5v above it's charge level, that voltage differential causes current to flow into the battery, as the battery's voltage rises, the current begins to dip, every 2 seconds or so, charging ceases, voltage stabilizes and voltage taken by the arduino...

The new voltage is now the new voltage of battery + .5v

This should give interesting pulse charge swings to the battery...

I'd apply this to a lead acid battery not a lithium. ...  any thoughts?
439  Community / Bar Sport / Re: Important safety warning. on: May 01, 2014, 11:24:06 pm
You mean i can no longer shower and solder at the same time, it was great for washing off the flux!
440  Using Arduino / General Electronics / Re: Resistors in a circuit on: April 29, 2014, 09:10:19 am
Oh look, the same question asked again...


not sure which is worse, the same questions, or the same REPLIES over and over again.
441  Products / Arduino Due / Re: emulate open-collector with Due on: April 28, 2014, 11:19:35 am
I just designed this circuit to give you a 5v high from as little as a volt.

Just pnp and npn standard transistors
442  Using Arduino / General Electronics / Re: Need Help Identifying Components on: April 27, 2014, 09:11:46 pm
3 - looks like an inductor.
6 - a Diode
7 - not sure, either a crystal or an inductive lamp or bulb or maybe fuse?

1 a. is capacitor probably in the 200v - 300v
1.b a ceramic cap or maybe MOV (hard to tell with this picture, hard to read writing)
1.c a mov or ceramic cap,.

4 a. cap,b.relay,c. relay?
5 a 2watt 2ohm resistor

Probably got a couple wrong, 7 and 1
443  Using Arduino / General Electronics / Re: Transistor's base voltage.. on: April 27, 2014, 09:04:22 pm
if anyone thought i was claiming "transistors can only handle up to 6v' no wrong, i've used 12v myself plenty of times, I did not realize that the 6v figure was for "reverse" and i'm still not entirely sure ..

so if i apply -7v  to the base of the transistor it will begin to conduct at the breakdown voltage?.

or are you saying..

apply 7 on the emitter? and it will begin to conduct from the collector to emitter?..

this is what i mean by vague for me.....
444  Using Arduino / General Electronics / Re: Transistor's base voltage.. on: April 27, 2014, 08:59:04 pm
cjdelphi, there may be some hostility because you are a bit of a jerk when people disagree with you.

I'm a jerk to anyone who's being a jerk, i may not understand it, but my questions arise from not totally understanding it, and when others are happy with it /just does/ and does not question it at all, that leads to ignorance, if i'm going to use it, then i want to know how to fully use it.

Vague answers like 'it does'  is not an answer...

As for this question, why the hostility?  i'm not even disagreeing with anyone here let alone attempting to argue, so why the hostility, maybe it's it's just them.....
445  Using Arduino / General Electronics / Re: limit current or voltage for a device? (noob) on: April 27, 2014, 06:22:31 pm
Reduce the voltage,  don't limit the current...
446  Using Arduino / General Electronics / Re: Transistor's base voltage.. on: April 27, 2014, 06:06:40 pm
Are you saying up to 50v can be applied to the base?..  smiley-cool

I just could not let this rest.
I don't have one of those 2SC jobs, but I have a 2N3904 (lots of 'em). The 3904's VCBO spec is 60V.
I left 50V in the dust, I applied 73V to the Base.
The difference between VB and VC is 24V
1/4W on the little darling, too, but still.
Not much more to do with this circuit but to prove a point.
I can upload a video of the experiment if necessary.

[Coming Up... Panic in the streets]

I was merely confirming what I thought was true, that diagram and voltage is what I expected would happen, I've always stuck with 6v or less with the base pin.. you had no point to prove as I was not claiming anything to begin with?....
447  Using Arduino / General Electronics / Re: Why can i not slow charge a lead acid battery? on: April 26, 2014, 02:14:40 am
if you had to charge a battery in 3 stages like they say you must how can u know when one stage must be finished and the next stage must start? by measuring the battery voltage? but how do you do that when the battery is on charge? will you not measure the charging units voltage? or must you first unplug the battery from the charger and then measure the voltage then decide what stage it should be on?
The battery voltage varies all the time you are charging.  As I mentioned earlier the power supply's voltage is variable, so the voltage at any one point in time will be the charge voltage.  You can measure this at any time while charging quite happily.

ok so for example if i have a flat battery, it measures 10volts and i put a 14v charger on this battery and try and measure the batteries voltage with the charger on i will not get 10volts. so how can you know what the batteries voltage is while it is on charge??

2 ways.

1. Supply 14.2v, as the battery nears 14.2v  the current significantly drops and just floats, but this is constant voltage or cv, 14.2v.

2. Supply say 19v dc, regulate it for cv, then the current draw will be in the amps region, now we limit the current to say 500ma via circuitry or a simple resistor.  This then leaves you with a problem as you need to stop the charge, check the battery voltage, the enable charging again.... setting it to 14.2v and walking away is as easy as it gets.

448  Community / Bar Sport / Re: Water + drainol + aluminum = Power Source? on: April 25, 2014, 11:21:42 pm
infact, using the 2nd method, you could get a bigger balloon and have it take off ?
449  Community / Bar Sport / Water + drainol + aluminum = Power Source? on: April 25, 2014, 11:17:39 pm
Kid's are (on a safety note, this can be quite explosive...) currently using these 3 ingredients to make small explosives that are maiming kid's limbs, hands and mainly fingers.... so if you see a plastic bottle that looks suspicious, avoid it!

Video1: What can happen. (how to make)

Video 2:  How to harness this energy?...

i was thinking some kind of small hydrogen to electric, to power an arduino remotely for a few ??? i dunno how much hence why i'm here lol

450  Using Arduino / General Electronics / Re: Min high input voltage (Arduino Micro) on: April 24, 2014, 08:07:27 pm
You should be fine..... 3.3v should read as high.
Pages: 1 ... 28 29 [30] 31 32 ... 190