Basic Electronics Info For Noobs

[Mark Linehan]

Okay I know there are a lot of noobs like me to modding. I luckily have some meager electronics knowledge from a LONG time ago. I will share the knowledge I have with those out there who have little to knowledge, and I hope this will be helpful to someone. If this is of interest make sure to tell me and I will post more. Right now I am just posting some symbols for schemstics that I actually remember. I will look up more if there is interest in my continuing this chain of thought.

Battery - Pretty self explanatory, right? If you don't know what a battery is, then you probably should avoid modding for all of our sakes.

Capacitor - Stores a charge until needed, sort of like a tiny temporary battery

LED - Makes a pretty light when Volatage applied (always use in line with a resistor or your pretty little light will only be really bright for a split second. Then it just smells bad)

Resistor - This cuts down the amount of current flowing through the wire it is on.

Ground - A solid negative point for your circuit.

Diode - Restricts the current flowing in one direction

OP Amp - Versatile components usually in IC form that perform many possible functions and are often used as amplifiers, inverters, comparators and more. These you would want to look up to get a grasp of the big picture.

Switch - Used for enabling or disabling a circuit by allowing current/voltage to flow through it. There are SO many switches, you would need to look them all up. The one I drew is a SPST Single Pole Single Throw switch. The simplest form of switch I think.

Variable Resistor - This is a resistor that can be modified for resistance, usually by means of a small screw or something similar. You can make versions of these using a circuit made with a series of resistors and a sliding switch.

Potentiometer - This is a resistor that has a dial in most cases and is meant for allowing the resistance in a wire to be modified while the circuit is live. This is something you would expect to see in a communications device.

Transistor - The easiest description for a transistor would be A transistor is a regulator for current or voltage and can be a switch or gate.

I can do tons of more drawing and simple layman posts to describe them if anyone wants me to. I can even do some simple schemetics to give you an idea of what they look like. Doing this will help me re-learn what I have forgotten and get in practice for my upcomming modding and will help others learn ideally.

When I start modding I intend to take a lot of pictures and post complete visual walk throughs of everything I do.

Let me know what you think please.

Mark Linehan

 

[slopes]

Thanks Mark. This should be a sticky.

 

[Mark Linehan]

Part II - Understanding & Reading Resistors

There are color bands on resistors, and once you know what the bands equal you will see that it is actually very easy to read a resistor. Most of them will most likely have 4 color bands on them. These are two DIGIT bands, one MULTIPLIER band and a TOLERANCE band. If you have a resistor with 5 color bands, then you have a 1% resistor, which means it has very little fluxuatioin in resistance quality.

For a 4 band resistor you read the first color and consult the color chart to see what the number is, then the same for the second color band. These two numbers are not multiplied or added together or anything. They are simply a two digit number. The color sequence equaling the numbers 0 thru 9 are black, brown, red, orange, yellow, green, blue, violet, grey and white. black is 0 and white is 9. There is a simple phrase I was taught in school to memorize the color sequence, and I will share it with you except that I will change the R word for red to ROB instead of the somewhat inflammatory word I was taught to use, even though I never forgot this. Just remember:

Bad Boys ROB Our Young Girls But Violet Gives Willingly
Black Brown Red Orange Yellow Green Blue Violet Grey White
0 1 2 3 4 5 6 7 8 9

So a resistor where the first two color bands are Yellow and Violet would mean the numbers are 47. Now the third color band is the # of 0's you add onto the end of your two digit number. For instance, if the third color band is a 1 then the resistor is a 470 ohm, and if the third color band is a 3 then the resistor is a 47K ohm. It is THAT easy.

Now if it is a 1% resistor then you simply have a third digit color band. ie. digit-digit-digit-multiplier-tolerance

Noe the tolerance band is always the last color band on the resistor. If it is a red band, then the tolerance is 2%, gold is 5% and silver is 10% and no band is 20%. A resistor that has a 20% fluxuation possible kinda scares me a bit.

So if you had a 1K ohm resistor with a gold tolerance band, then that resistor could be anywhere between 950 ohm and 1050 ohm and if it had a red tolerance, then it could have been anywhere between 980 ohm and 1020 ohm. I think you probably get the drift here.

Here are some examples..

FOUR BAND

red green blue gold - 25M ohm with a 5% tolerance 2.375M to 2.625M ohms
blue brown yellow silver - 610K ohm with a 10% tolerance 549K to 671K ohms
orange red green none - 3.2M ohm with a 20% tolerance 2.56M to 3.84M
(see why 20% scares me a little)

FIVE BAND

brown brown red red red- 11.2K ohm with 1% tolerance
blue brown red blue red- 612M ohm with 1% tolerance

If you have any questions, or if I left anything out, PLEASE do not hesitate to let me know!

Mark Linehan

 

[bigblue30]

When I learned that 30 some years ago we used different words bad "bad" and "ROB"....lol.

 

[CloudBurst]

Ok, here is the dumbest question of the day for ya...I know from experience (lots of dead LED's) that it makes a difference which end of the resistor goes towards the LED, how the heck do you know that?? And don't tell me one of the legs are longer on one like the LED cuz I just thought of that but never checked! LOL Like the + LED leg being longer, they assume everyone knows this important detail but WE electronic know nothing's do not.

 

[bigblue30]

As an electrical engineer for over 30 years....I can tell you that it does not make a different what the direction is for a resistor. Now if you want to make a pretty circuit......resistors should be read from left to right and top to bottom. That is only for looks.

 

[CloudBurst]

really? Hummm, must have just had a few bad LED's then! Glad to finally get a straight answer tho, helps alot! I can barely see the colors let alone put them in any order! Thanks BB.

 

[Mark Linehan]

BigBlue is correct. Resistors are bi-directional. It has no positive or negative side to it. The LED does have a + and - though, as you stated. The longer leg is the positive leg. I also don't think it even matters if the resistor comes before or after the LED as long as it is in line with the LED it does it's job. Can someone confirm that for me?

 

[Mark Linehan]

When I learned that 30 some years ago we used different words bad "bad" and "ROB"....lol.

Okay I know ROB would be a certain act of violence on a victim that I thought better to leave out in this discussion (ahem) but what did you have in place of "Bad" ???

 

[CloudBurst]

This is great stuff...thanks for posting!

 

[Mark Linehan]

Okay, this is another fairly straight forward concept, but it is definitely one of the most important and widely used formulas you will make use of when it comes to circuit designing and analyzing.

When you are working with a circuit you will often want to know the values of resistance, current and voltage at any given time. Sometimes you will want to know this sort of thing BEFORE you actually turn that puppy on and start yelling colorful expletives at yourself and your now sizzling components.

Well, I personally use Ohms Law for figuring out (I) current more than anything else. This is simply because I like to think I always know what voltage I am introducing into my circuit, and the resistance can generally be summed up by calculating the resistors and any other components that can offer any realistic levels of resistance. Ohms Law is the formula that helps me determine my (I) current when I only know the (V) voltage and (R) resistance of my circuit, or part of that circuit.

Ohms Law is a set of THREE math formula. These are easy to remember.

V = R * I ( I remember this by remembering the word VERY for VRI )
Voltage = Resistance * Current
I = V / R
Current = Voltage / Resistance
R = V / C
Resistance = Voltage / Current

Here are some simple examples.

Assuming a circuit of 5v and 470 ohms
I = 5v / 470ohms : I = .01a (actually it is like .01063... amps, I rounded off)

Assuming a circuit of 3a and 5v
R = 5v / 3a : R = 1.6 ohms

Assuming a circuit of 200mA and 470 ohms (200 milliamps is .2 amps)
V = 470 ohms * .2a : V = 94v

Now there are more formulas for Ohms Law you should know as well. These involve (P) power and is measured in Watts. These formulas are used less and most people concentrate on memorizing the VRI formula, but it does not hurt to memorize these either.

V = I x R or Voltage = current times resistance
I = V / R or Current = voltage divided by resistance
R = V / I or Resistance = voltage divided by current
P = I x V or Power = current times voltage
P = I² x R or Power equals current squared times resistance
P = V² / R or Power equals voltage squared divided by resistance

Examples using a circuit with (P).4w (I).2a (V)2v and (R)10 ohms It may seem strange that I am giving you all of the values before hand, but I think this really helps you grasp the relationships this way. I can give more examples, and more obscure values if you think that might help.

V = R x I
V = 10ohms * .2a : V = 2v
I = V / R
I = 2v / 10 ohms : I = .2a
R = V / I
R = 2v / .2a : R = 10 ohms
P = I x V
P = .2a * 2v : P = .4w
P = I² x R
P = (.2a * .2a) * 10 ohms : P = .4w
P = V² / R
P = (2v * 2v) / 10 ohms : P = .4w

It's all pretty easy actually. The hardest part is memorizing the formula, and I stick with VERY which makes me think of VRI because if you say VRI it sounds like VERY. When I know VRI is V = R * I because the first letter is the = letter or V= and the next two letters are right next to each other which is normal math notation means they get multiplied, so V = R * I. VRI.

Now since V = R * I, then you can simply deduce that I = V / R and naturally that means that R = V / I. Well that's what they told me in school. I kinda sucked at math though, and just memorized the 3 functions, because I honestly could not tell you why V=R*I means I=V/R and R=V/I. I just know the math works so I use it.

Okay, so there is the BASIC version of Ohms Law. I could go on for pages more actually, but I won't. That is the general idea and is enough to get you started. If you are a math whiz, then there are a whole plethora of web sites out there that go way too far into the depths of aneurysm inducing math algorhythms and multiple pie charts, slope calculations and relational formula that frankly make my eyes bleed.

As usual, any experts on these topics that are bored enough to be reading my basic electronics information, please correct any mistakes I have made. I have been out of school a VRI VRI VERY long time and am doing this partially to dremel the rust off my flesh transistors as well.

Mark Linehan

 

[Liv2Ski]

Mark Part III brought me back to Physics one. Please don't explain Kirchoff's law!!!! Anyway great info and nicely stated. I may link to part III for those that ask "why LR atty on 3.7 (or 3.3 for eGO) volt devices". Thanks for the post and effort you put into it

 

[cadcoke5]

It is important to realize that LED's are not like regular light bulbs. If they do not have a resistor inline with them, they will always allow enough current through them to destroy themselves. There are a number of web sites that have "LED Calculators" that will tell you what value resistor you need when connected to your power source of choice.

Here is one LED calculator; LED Calculator - Current limiting resistor calculator for LED arrays

Joe Dunfee

 

[Mark Linehan]

So it appears that soldering is one of the skillsets that seem to scare people away from modding. Soldering is really not all that difficult as long as you take the time to be prepared and never try to rush through a soldering task. So I figure the best way to do this will be to just list in steps the process of soldering a wire onto a part. I will then list the best hints & tips I can think of afterward.

For this step-by-step I am going to give the process of soldering a wire onto the center pin of a 510 battery connector. This is one of the more difficult parts to solder onto if you do not approach it correctly and from what I have read there have been a few people who beat the heck out of their connectors just trying to solder on this positive lead.

STEP-BY-STEP

(1) Clean the tip of your soldering iron. If it is new or if the plating has worn down on your soldering iron tip, then use the wire brush cleaner attachment of your dremel to clean the tip of your soldering iron (or light sandpaper). Then wrap a few turns of solder around the tip and plug it in. The soldering iron will then heat up and when the solder melts it will tin and improve the surface/plating of the iron. A common problem with most amateur soldering is using a non-tinned/plated soldering iron or worst of all a dirt soldering iron. You want a nice tinned/plated iron tip for the best results. Always clean your solder iron tip with a wet sponge even if it is tinned already.

(2) Push the center post out of the 510 battery connector. It should slip right out of the rubber gasket that provides the seal around the center post and prevents it from shorting out against the side of the connector.

(3) Use the wire brush attachment or light sandpaper to clean off any surface coating from the bottom of the center post. This will help the solder attach to the metal.

(4) Place the flat edge of your soldering iron against the side of the center post right near but not ON the bottom. Once the post it hot enough, you can apply a small flat sheen if solder to the bottom of the post. This is pre-tinning the component. If you cleaned the post properly and made sure the surface is not a shiny coating anymore then the solder should tin it up nicely.

(5) Strip off about a 1/4 to a 1/3 inch of insulation from your positive lead/wire.

(6) Place the flat edge of your soldering iron against the wire and it will heat up fairly quickly unless it some ungodly thick gauge of wire. Place the end of your solder against the opposite side of the wire and not touching the soldering iron. The solder should then make a nice even coating on the wire. Your wire and post are now tinned.

(7) Place the flat edge of the soldering iron against the side of the bottom of the center post again, and place the wire against the very bottom of the post, not the side or too close to the iron tip. Now you should only need a very small amount of solder to connect the two together.

(8) Once the solder has cooled you can slide the center post back into the connector. Use the small flat end of a drill/dremel bit to be sure the center post is properly seated back in the connector.

(9) Once the connector is back together you can, if you wish, place a bead of epoxy or hot glue over the soldered connection on the center post. This will insure no possibility of the wire coming loose and shorting out and will even strengthen the connection a bit. I only recommend doing this on the center post because you are soldering a wire onto a flat surface which is one of the more difficult joints to make.

(10) After you cool your soldering iron down, clean it off with a wet sponge again.


HINTS & TIPS

1. Get yourself a high-end soldering iron with adjustable power level. Using an iron with too much heat is a surefire way of damaging components. You will see this happen a lot when working with wires, when the iron is too hot for a thin wire, the insulation will melt, wrinkle up and smoke. A good soldering station will have a coil stand to hold your soldering iron in, a small well for a sponge and some water and a place to hold a coil of solder and some braided wire and have a controllable power supply.
2. Always pull the solder away before the soldering iron to make sure the solder does not stick to the wire/component.
3. Do not try to leave beads of solder on your connections. Having big globs of solder does not make a better or even stronger connection. In some cases it can make a connection more prone to shorting out if you are working in tight spaces.
4. Always use solder with a rosin core. The chemical reaction of the rosin on the surface of the metal will help insure a nice even tinning before making the actual solder joint.
5. Try to use lead free solder when possible, and especially when making a device like an e-cigarette with a bottom feed/wet box type configuration. The solder with lead in it could potentially give off fumes and microscopic particles from the lead based solder, and we don't anyone to be breathing that junk in. Not even people from the FDA or bid tobacco! NO! I'm sorry. Not even them. I'm putting my foot down.
6. Never try to catch a falling soldering iron. You have a better chance of quickly picking it up without burning the floor/rug/desk than you do of not burning your hand when you accidentally grab it by the metal iron.
7. Always try to heat from near the connection point and not where the solder will actually touch the iron tip. Touching the iron tip will lead to messy soldering joints.
8. Use low power soldering irons when working with very small or very sensitive components. Otherwise the excessive heat could easily damage your components.

I hope this helps. I know I put some soldering information up somewhere before, but I can not remember where and I don't think it was quite as involved as this one. It might have been just as a reply to someone else' soldering how-to. If anyone has any corrections or additions to this information, please feel free to chime in! I learned how to solder almost 3 decades ago so there could very well have been a dozen changes, improvements or obsolete items in that time. I can still wield a soldering iron, but it is a very old one, and it took a bit for me to start to get the hang of things again. I won't even post pictures of what I did to my poor free MadVapes plastic flashlight. Needless to say, I ended up using a stupid big harmonica case for my 5v pass-thru container.

Any questions? Don't hesitate to post. I hope this information is being useful to people. At this point, I would like to ask for suggestions from the less electronically knowledgeable forum members as to what topics I can cover for them in this thread. Please just PM me with the suggestions for more topics, but feel free to reply with comments, corrections or other feedback.

 

[WillyB]

It is important to realize that LED's are not like regular light bulbs. If they do not have a resistor inline with them, they will always allow enough current through them to destroy themselves. There are a number of web sites that have "LED Calculators" that will tell you what value resistor you need when connected to your power source of choice.

Here is one LED calculator; LED Calculator - Current limiting resistor calculator for LED arrays

That's all well and good, unfortunately many suppliers do not provide the 3 relevant values of the LED to plunk into the calculator.

3mm Red LED

5mm Blue LED

And the calculator is giving you the value needed for maximum brightness, something I for one don't want.

In general to protect an unspecified LED at 3.8V 100Ω and higher will work. At 4.2V 120Ω and higher. At 5V 180Ω and higher. For 8.4V 330Ω and higher.

Using a higher value (which I suggest, unless you want a flashlight) will dim the LED.

 

[happest]

Resistors question. please correct me if I am wrong. I am making a USB car charger for a 5v 2a passthru. I go and get a 5v 5a car assessorys part and want to reduce the 5a to 2a. so If my math is correct 5a/2.4kOhm = 2.08333a. go to radio shack and ask the clerks, they have no clue. So I look thru the shelves and find them but they have 1/8watts 1/4watts 1/2watts versions. Im no electrical guru only what I see here. which one do I want? or do I need a different one due to the addy having 3.4Ohm resistance (Standard 510)

 

[Mark Linehan]

Wow. Well, I'll be honest, as I said in the beginning I am refreshing my memory while sharing my relearning with everyone else who is a newbie to modding. Calculating the power end of Ohms Law was never my main focus for any projects. So I would appreciate it if someone without as much rust on their multimeter as myself can confirm all this for me.

I really don't think you want to use a USB charger that has outputs of 5v AND 5a. The 5a is quite high. Not to mention, if you throw a 2.4K resistor into the mix you are going to skyrocket your voltage and bottom out your current.

You will have 25 watts of power with 5v and 5a.

The best thing I can suggest for you, and I have seen others do this, is buy a standard 510 usb charger (which is 4.2v and 420mA I think, or is that for the ego charger only???) Anywho.. Buy a standard USB charger and just remove the two connectors, and wire the charger into your circuit. This is probably the easiest way to do this, and these usb chargers are actually pretty inexpensive. I have a broken one that the battery connector came out of, and I am going to do exactly what I am mentioning here when I build another 3.7v mod out of a flashlight. You can purchase some very inexpensive 510 usb chargers right at THIS LINK.

If you want to see one of these usb chargers built into a mod, check out THIS LINK and you will see that it is fairly easy.

Now I am rusty, so maybe I am overlooking some simple way of dropping your amps down without messing up the volts and current and requiring further circuit modifications, etc. So if anyone can jump in and save me on that, please don't hesitate. As I said many times before, I am not just helping to teach, I am re-learning stuff from almost 3 decades ago.

 

[happest]

Please forgive me. I think both of us got confused first my calculations are wrong 5a/2.4Ohm = 2.08333a (that little k makes a huge difference) second is what Im trying to make It will look some thing like this but have a USB cord coming out instead of all enclosed. I maybe wrong but I did not think it would be that hard. just slap a resistor in line and USB cord and go

 

[Mark Linehan]

Okay, but you are still looking at P = I² x R

Now you are working with 5 amps. You also have about 2.7ohms of resistance in the nichrome wire that is your atomizer's heating coil. So you will actually now have 2.7 from the atty plus 2.4 from your added resistor. So..

P = (5x5) X (2.7 + 2.4) = 25 x 5.1 which gives you like 127 watts. Unless I am missing something here, if you put 127 watts across your atomizer coil, you will not be vaping for very long with that atomizer. You did say you wanted to use this as a combination charger/passthru right?

If you go with the standard charger, 420ma (.42a) the math is..
P = (.42x.42) x 2.7 = .1764 X 2.7 = .47 watts Just to show the vast difference in power, as far as I can determine anyways. I think I have the power formula correct.

 

[WillyB]

Resistors question. please correct me if I am wrong. I am making a USB car charger for a 5v 2a passthru. I go and get a 5v 5a car assessorys part and want to reduce the 5a to 2a. so If my math is correct 5a/2.4kOhm = 2.08333a. go to radio shack and ask the clerks, they have no clue. So I look thru the shelves and find them but they have 1/8watts 1/4watts 1/2watts versions. Im no electrical guru only what I see here. which one do I want? or do I need a different one due to the addy having 3.4Ohm resistance (Standard 510)

First off what is a '5v 2a passthru'? Never heard of such a thing. Your PT is just a cord, switch and connector?

5a/2.4Ohm = 2.08333a

5A with a 2.4Ω load = 12V, 2A with a 2.4Ω load = 5V

Are you using a 2.4Ω atty? And an authentic Joye 510 atty is 2.1-2.2Ω, which is what I consider the standard. Are you trying to get a true 5V with a 2.4Ω or a 3.4Ω atty? You post is most confusing.

If so if you if you have a regulated ' 5v 5a car assessorys part' just plug your PT into it. Many common wall warts are not regulated, one that says 9V will usually read about 12V without a load. Check your car adapter's voltage. If it's around 5V you should be good to go. At 5V your 2.4Ω atty will draw 2A, nothing else is needed. It makes no difference that the 'assessorys part' can deliver more amps. A 2.4Ω atty will only draw 2A at 5V.

If you are using a 3.4Ω atty at 5V it will draw about 1.5A irregardless of the adapter's amp capacity.