Basic electrical

[Normk]

Let's hear whether a longer article such as posted is the best or whether small, how to is most desired.

Here's a small one. Dig out your multimeter and find the Volts range of settings. Does your meter have several settings? Or does it just have one volts setting on the switch?

Does your meter have a selection to choose between AC or DC?

All of these questions are basic to meter use and are part of the baby steps to getting up to speed. Like most things, once you get moving, things come faster and faster.

If your meter has only a volts setting, then there must be another means of switching between AC and DC, find that.

OK, let's assume that your meter has only volts settings for AC or DC with no means of choosing the maximum voltage to be measured. That means that your meter is most likely an auto ranging one. Some of the meters which allow a choice of range will auto range but let's consider the implications of the ranging.

When you turn your meter on and switch to volts, select DC and are thinking of checking something such as the batteries from a flashlight which is going dim, or that TV remote which doesn't work, or maybe your bike's charging voltage, you will need to consider the expected voltage which you will measure. The bike's system makes just less than 15 volts maximum with the flashlight and remote less than that.

OK, when you touch the test leads to the battery, the meter will indicate the voltage sensed between the leads. Nothing new there, right?

What can be confusing, very confusing, is that the meter may indicate a higher number when the leads are not touching the battery than when they are. Try setting your meter to DC volts, if it has choices for voltages, set the scale at the range which is just over 15 volts (say 20 if that's the choice) and touch the leads to the battery. What do you see?

If you see 12.8 then you are seeing a fully charged 12 volt lead acid battery. But when you remove the leads, maybe the meter says 134, so what's going on? Have a close look at the scale and you will likely see a symbol such as mV, or milli, something like that.

What is happening is that the meter is auto ranging. It has automatically switched to a lower voltage scale in order to display the voltage which it sees in whole numbers. It is sensing, maybe, 134 millionths of a volt from magnetic effects out of the air. That's the 134! This can drive you to distraction if you are checking something which has an extremely low voltage, for example because the auto ranging switches down and displays a bigger number because you didn't notice the scale change.

Don't feel foolish as we have all been bitten by that when checking and not thinking about the meter display.

What about other scale settings?

Let's say that your meter allows you to select ranges such as 100 mV, 1 V, 10 V, 20 V, 100 V, 1 kV, 10 kV. OK, so how to start?

Remember the meter rule that someone has likely told you, "Always start measuring with a meter setting higher than the expected value to be read."

If we don't know the voltage to be encountered, we set the above meter at 10 kV (10,000 volts) and take a measurement. Hook it to your bike battery and it displays? Zero, unless it is an auto ranging in which case it will set down. Let's assume the meter doesn't auto range.

Nothing, zero on the display so, disconnect the meter leads, set to 1 kV (1,000 volts) and test. Keep going until you see a meaningful value. Try it on your bike and some batteries around the house.

OK, "I've tried all sorts of things but get meaningless numbers! What now?"

Have a look at the meter again, does the display say "AC" or "DC" Volts?

If it shows "AC" then it is likely to show silly numbers because it is likely auto ranging down to the 1/1,000 volt or 1/1,000,000 volt range and picking up induced voltage from the air. You may have to dig out the book or just have another look to see if the switch needs to be set to another area (AC voltage ranges are usually grouped in a separate area than DC).

Nothing lost here as you have now noticed that the meter will auto range down on AC also and find meaningless numbers so you won't be surprised to see that happen when you are working. Switch to DC and try some measurements again. Write them down but don't worry much about what they mean as we will get to that later.

Try this one for fun: take a penny and a quarter, wet a piece of paper with saliva and place it between the two coins. Measure the voltage with one meter lead on each coin. What voltage do you read?

Let's see a few numbers indicating voltages read from your bike battery, and some other batteries around the house.

Have you noticed that your meter shows a "-" sign sometimes beside the value? How about a "+"?

The meter expects that the red test lead be plugged into the meter's "+" (positive) or red socket and the black lead into the "-" (negative) or black socket. It also expects to encounter a polarity of postive at the red lead, negative at the black.

How your meter reacts is something you will need to know. Most modern digital meters simply switch polarity automatically if you have the leads in the opposite polarity but a few will show and error message or some other indication that you need to reverse the leads.

Knowing how your meter shows polarity is like having money in the bank as it can save you from hooking up that expensive GPS in the wrong polarity and letting out the smoke.

I'll leave it here for now until we see some feed back.

Let me know how this is going for you as I can shift gears to another area or try another tactic if that is more useful. Do dig out that meter and play around. As long as you avoid the scales other than volts, you are extremely unlikely to do harm to anything.

Once we get you up to speed to measure some values, we can move to Ohms, Amps., etc. Stay away from those scales if you hook the leads to power as you may let the smoke out of the meter.

HIH

Norm

 

[Normk]

I'm willing to work on this with you but need feedback as to where my attempt went off the rails. Keep in mind that I am trying to present the subject so if it's not on target, I'm the one missing the aiming point, not you.

Someone commented in another post that I need to get a thicker skin. Not going to happen. I am not prepared to volunteer time and take pooh and don't expect anyone else to be different. If something I write seems to show disrespect it is being misread because I crafted it poorly. Please PM and let me know how it went wrong so that I can clear the misunderstanding.

I have taught several hundred college trades students to use meters and to make electrical measurements but that is an easier prospect than doing so over the net to people who haven't even met. It is an extremely challenging and interesting problem which is what I get out of the process. That and my Mom taught me to try to help nice people.

Norm

I read it all and can appreciate the time you took to explain it all fully to us with no electrical training. Thank you for your time and input even though some of it went over my head like a screaming rocket.

 

[keman]

Sounds like you are on the right track. I know it can be a lot of work. I have done my share of teaching in my industry. I know it can seem like taking to a wall sometimes.

 

[koolaid_kid]

I've been reading your posts, and I agree some feedback would be nice. As a EE and a former teacher, it can be frustrating when the students just stare back at you.
However, you make some valid points about the auto-ranging meters. I don't like a machine making decisions for me, and I want to be able to set the range I want. (It's a control thing.) I much prefer a meter that lets me set the range, and I like ones with auto-off. I occasionally forget to turn it off, and replacing the batteries can be a pita. Just a thought.

 

[bccap]

Am following closely, and for the most part understanding. Will reserve questions til you are through the rr test, where I do have a question re stator paper tests.

 

[Normk]

Thanks for the feedback!

Koolaid mentioned part of the automatic issue which I forgot to mention. Auto off meters can be very useful to avoid killing the meter battery(s) but some have a short time out and don't sense whether there is activity affecting the meter. These units can be quite annoying over time by shutting off when one is part way through a procedure.

If you find that your meter shuts off too soon, one way to address this is to try switching to another setting and then back (with leads not touching power, of course). This will usually reset the meter's shut off timer.

Chores to do, a friend's old ATC to finish, friend to meet for coffee & my mother's car goes to the glass shop for a new side window. I may not get back to this project until later.

HIH, and please keep the feedback coming. Especially the hard to discover issues regarding where the explanation missed its target. I will make some diagrams of basic voltage and voltage drop tests to post as part of that.

Norm

 

[cowboyup3371]

I've been reading as well but it's hard to know what questions I want to ask right now. It seems like your posts are on target but also seem to jump a little (discussions about stator and regulator/rectifier) so I'm still trying to process.

Please keep going and I'm sure questions will pop up.

 

[tas850g]

Analogies are good, keep them coming.

It can be a little wordy at times so I have to keep my ADHD under control.

Will continue to follow the thread.

Nice work Normk.

 

[alke46]

Analogies are good, keep them coming.

It can be a little wordy at times so I have to keep my ADHD under control.

Will continue to follow the thread.

Nice work Normk.

What he said. Very interesting but do not know what to ask yet. Luckily, I am not experiencing any electrical trouble on my bike as of now.
Thanks again for your time and instruction.

BTW, you and I share a common interest in the Honda ST 1100. Wish the Suzuki had the same charging system as the ST .

 

[phatphony]

awesome norm thanks heaps

 

[Normk]

alke46, is yours ABS/TCS? I see 1993 so have you the 28 amp. alternator or upgraded to the 40 amp?

The ST1100's 28 amp. varies in output as I have measured maximum outputs from around 28 amps. to as high as 32. The 40 amp. is a Nippon Densu whose "guts" are largely identical with and replaceable by, the automotive versions. The 40 amp. is a bit of a mis-label as typically a ND 40 amp. will produce close to 45+ amps. ND apparently stopped making the 40 amp. version of that alternator family so the more recent ones sold through Honda are the 50 amp. version. Mine actually makes 59.6 amps. at full output.

Poor old (1979 GS850G) Suzie makes a maximum of 14 amps. with 8 required by the bike to operate ignition, normal lights with the HID on. This obviously leaves only 6 amps. available for recharging the battery, etc. As Julia Roberts said, "Big difference! Huge!"

I haven't heard any feedback in terms of measurements from the headlight circuit, etc. as yet. Any takers?

Let's move in a different direction while awaiting some results:

People sometimes express concern that a larger alternator may over charge the battery in much the same way as connecting an automotive charger to a bike battery. There are also concerns and myths regarding using jumper cables to start a dead battery bike.

Let's have a quick look at those issues.

First the use of jumper cables and such. The difference in physical size of an automobile battery versus a motorcycle's worries some in that is might appear that the bigger battery might provide too many amps. (too much electron flow) to the bike and so cause damage. Not a problem!

Remember the attempt at explaining the alternator's action in using magnetic lines of force to push against the electrons in the stator wiring? The effect creates the electrical "push" which we call voltage. The amount of current which will flow in a given circuit depends on how much voltage is available to push electrons against the electrical resistance (friction) in the circuit.

If we select a tiny dash light bulb such as a #194 which is designed for 12 volt operation. Connect this little guy across a bike 12 volt battery and it lights up as intended. Connect it to a car 12 volt battery or a bank of huge 8D batteries in an off highway excavator and the bulb lights up to the same birghtness as designed. So long as the battery is big enough in capacity to maintain 12 volts across the bult, it will create the same current flow, the same heat and same light as when connected across the biggest.

This is not the case if we were to connect the bulb to a 6 volt battery where it would glow dimly, or across a 24 volt one which would burn out the bulb rapidly.

Since all modern cars excepting some hybrids, etc. have 12 volt systems, there is no problem in jump starting (using power from one battery to assist another) a bike from an automobile battery. Providing** one takes some precautions, but these are not rocket science.

Precaution #1 is the same as when jumping any vehicle which is to use correct polarity in connecting positive to positive and negative to negative.

1B. is to connect the postive jumper cable to both batteries and then to connect the negative cable to the negative of one battery or to a good ground such as the alternator bracket. Next, connect the other end of the negative cable to a good ground such as engine bolt or alternator bracket on the other vehicle. Do not connect the last negative lead to the battery.

This last is important because the last connection will create a small spark which just might ignite gasses from the battery. See in happen several times. Boom! Pieces of battery case and acid flying.

Actually, one of the most satisfying experiences of my life was, after nicely cautioning a young man to this effect and having been even more politely told to proceed to have sex with myself, hearing a loud "crack" and hearing him screaming. Garden hose to wash acid from eyes and skin then off the the hospital for treatment of acid burns and cuts. Make no mistake, it happens folks! Several batteries blew up on chargers during my years in the colleges.

Back to jumping: Ok, so what other concerns must be appreciated if attempting to jump a motorcycle from an automobile?

In short, do not have the automobile's engine running while the bike is jumpered to the auto battery. Don't have the car's engine running and that will keep you safe. If you care about why, I will try to explain.

The myths mainly revolve around the issue of the bike's charging system and here are some real risks. As I tried to explain earlier in this thread, there are two main types of charging systems used on motorcycles, those which have permanent magnet alternators such as our GS Suzies and those such as Suzi Bandit, Honda ST's, Gold Wings, some BMW's, etc. which use a controlled field alternator.

Many/most/some (take your choice as I'm not up to argue) permanent magnet alternators use what we call a "load type" voltage regulator which limits the bike's charging system voltage from becoming too high by loading or "dumping" current to ground in order to absorb excess alternator capacity. We could accomplish the same end by the use of a large capacity load cell but that would require constant manipulation.

On another thread, recommendations are offered as to replacement of the VRR by some Honda and other units. These units can be as good as or better than the original but there is one important consideration which is that the capacity of the rectifier section of the VRR must be capable of accepting at least as much current as the system provides. If a VRR from a larger capacity charging system is selected then it can be expected to last longer than the original.

In the same manner, the voltage regulator section of the VRR must be of larger capacity since it functions by accepting the excess current capacity of the alternator if of a load type. Install a smaller capacity unit and "POOF".

Let's consider the old Zenor diode as the simplist example of this load type system. Connect a 14 volt Zenor diode across the GS charging circuit and it will do nothing until the alternator produces enough output to push the voltage above 14 volts. If the voltage begins to rise above 14 volts, the Zenor will begin to conduct current (amps.) to ground, absorbing the alternator's output. In this manner the Zenor limits the voltage.

When choosing a Zenor, the maker needs to consider the intended charging system voltage and the alternator's output. In the case of my old GS with a 14 amp. maximum output, a 14 amp Zenor would handle the regulation but it might be decided to use a smaller capacity such as 12 amp. because the bike can't run without the load of the ignition system but the sense of the equation remains.

OK, for our purposes, let's take as a given that Suzuki has designed a 14 amp. load capacity into a Zenor-like voltage regulator on my bike. The battery is dead so I roll the bike over to our Nissan and connect the jumper cables. The Nissan's battery, of larger capacity than the GS one, will maintain a higher voltage (but still at or below 12 volts) during cranking than would the fully charged GS one so the bike will crank a bit faster but all will be well. Bike starts, wait a bit to let the bike battery accept a bit of charge, disconnect one negative cable from chassis, and all is well.

How about if I ignore the advise regarding not having the Nissan's engine running? The Nissan's voltage regulator has a 14.8 volt set point and a 120 amp. alternator. With the Nissan engine running, the bike will crank even faster because the Nissan alternator is more than capable of providing enough current at 14.8 volts to crank the bike engine. That's good, right? Faster cranking and higher ignition voltage means faster starting?

That's all true but consider the bike's VRR which (assuming a load type) will begin shunting current to ground in order to limit voltage to 14 volts. As soon as the bike's VRR begins shunting current to ground and pulls the voltage below 14.8 volts, the Nissan's voltage regulator will increase alternator output in an attempt to maintain 14.8 volts.

A struggle will occur with the bike's regulator shunting current and the Nissan's alternator dumping out more current to maintain 14.8 volts. Trust me, the bike's regulator will loose and loose badly. It will burn out in less than a few seconds. The safe way is to have the vehicle engine off during jumping unless you are jumping an ST1100 or other bike with controlled field alterntor.

An alternative is to unplug the bike's VRR during cranking which will protect the VRR but, unless you're an accomplished juggler who can disconnect a jumper cable while, phased right behind that, reconnecting the bike's VRR, the bike will likely die because of insufficient power from the battery.

Ironically, one could use the GS jumpered to the automobile to, eventually, recharge the automobile battery but the bike is liable to melt from running for so long without air flow.

Next, a quick overview of chargers & charging.

HIH

Norm

 

[Normk]

I think we talked about battery chargers and smart chargers but let's touch on charging again as this is one of the least understood areas of electrical.

The bike charges its own battery whenever the bike's charging system is able to drive the system voltage above that of the battery. With some limitations, the greater amount by which the charging voltage exceeds the battery's voltage, the faster will be the charging of the battery.

Vehicle charging systems operate with set points (usually) between 14.2 and 14.8 volts so let's use those numbers for discussion purposes. If you have taken your voltmeter to some measuring excercises, you will have measured the charging voltage of your bike and hopefully other vehicles to which you have access. You will have noticed that all have similar voltages with engines running, on other words, charging voltage.

If we were to have left the bike jumpered to the Nissan with the VRR disconnected, or have taken the bike battery out and jumpered to the Nissan, we could have started the Nissan's engine and then used the Nissan's system to charge the bike battery. Since the Nissan and bike charging systems both use about the same voltage range, the bike battery would charge (recharge) at about the same rate from either source. The important thing is the voltage being applied as the battery doesn't know or care about the source.

In the same way, we could connect that old automotive battery charger under the work bench to the bike battery to charge it, right?

A qualified, "Maybe1?!". Here's the issue and how to deal with the question: As long as the charger applies a reasonable voltage (say 14-14.8 volts) to the battery then the battery will charge safely as it would do in the bike. The problem may be that the automotive battery charger is that it may not be very well designed and may be expecting some buffering effect from a larger automotive battery.

When ever you are using a battery charger to charge a battery, connect your voltmeter and monitor the voltage! Simple! As long as the voltage doesn't get too high or too low, then no problem. If it goes much below 14 volts the battery won't be charged.

If the voltage is going to high, the battery will overheat, experience eletrolysis and other issues but the voltmeter will warn you. One doesn't need to watch the meter constantly but monitoring, until you know what to expect from your charger, will keep things on the good side.

If the voltage goes too high, what then? Shut down and add some means of reducing voltage such as inserting a diode into series to drop voltage by between 0.7 and 1-1/4 volts, or add a resistance such as a light bulb. Some trail and error may be needed but it is also not rocket science.

My automotive 12 amp. charger will drive our motorhome's three, 100 amp, hour batteries over 18 volts when they are fully charged so not a very well designed charger! This one will cook (literally!) even the big bike batteries so I simply use additional control or use my small bike smart charger.

Time to take my son to soccer practice so hope some of this is of use.

What have I missed?

Norm

 

[alke46]

alke46, is yours ABS/TCS? I see 1993 so have you the 28 amp. alternator or upgraded to the 40 amp?

No ABS and stock from the factory alternator. No upgrades. And she is just 180 miles shy of 100,000 miles. Not bad for a '93 model since we have a 7.5-8 month riding season around here.

 

[Flyboy]

Many thanks Norm, following with great interest, love the layman's explanations.
Electricity has always been a dark art to me, but you are explaining it well and in an easy to grasp fashion.

 

[tas850g]

How about if I ignore the advise regarding not having the Nissan's engine running? The Nissan's voltage regulator has a 14.8 volt set point and a 120 amp. alternator. With the Nissan engine running, the bike will crank even faster because the Nissan alternator is more than capable of providing enough current at 14.8 volts to crank the bike engine. That's good, right? Faster cranking and higher ignition voltage means faster starting?

Question: because our bikes volts output is similar but the vrr amp. ratings are different this is the reason why we would over load our system and fry our electrical system? Our bikes vrr can vary but for simplicity my Honda vrr is around 40 amps versus a cars amps of 120 therefore, poof???

Can you explain a bikes amp output and how do we know what and how many accessories we can add to our electrical system without discharging our battery? Like if I want to plug in a radio, GPS, phone charger, and/or outlets for my heated vests and pants.

Thanks for your tutorials.

 

[koolaid_kid]

Normk, could you please explain the various terms used, and their relationship to each other, for everyone? Namely, the relationship of Power (rated in Watts), Current (rated in Amps) and Voltage (rated in Volts).
For example, the stator Power output is rated in Watts. The 1980 1100E was rated at 180 Watts. Please explain how this ripples through the system to obtain other values.
I don't want to hijack your thread, but I feel this very basic concept should be explained so members can understand how everything fits together as a system.
Thanks.

 

[allojohn]

This is excellent stuff Norm, keep it coming.

 

[Smellii]

Favoriting this thread. Electricals are my next project. Woot! Thanks Norm.

 

[Normk]

Happy to take direction, Koolaid, thanks! I'm simply trying to do something here which is useful so have no vested interest in any direction.

Did my attempt to relate voltage to "pushing' against the electrons work for those reading this? And do any of the exerienced electricals here have any reservations or wish to add clarifications?

The biggest problem with analogies regarding electrical is that the analogies only go so far and only work within the context intended so taking them out of that context will confuse things further. I'm concerned not to be doing this so having others monitor will help the process.

Volts: Electromotive Force, Electrical Pressure, effort acting to attempt to force electrons to move, etc. IMO, one of the most important aspects of the voltage concept is to recognize that there needs be no electron flow for voltage to be present. This is somewhat like the concept of tire pressure which is measured without (hopefully VBG) air escaping from the tire.

Here's another important concept regarding measurements: I don't thing anyone can quote me as saying something like "the voltage in the...." as this is a basic conceptual error. The voltage is always the difference in voltage between two points. When you place two voltmeter leads onto the battery, the meter is "seeing" the difference in pressure between the two points being sampled.

Here's an analogy: let's say that you are wishing to measure the height of a grandchild. In order to more easily measure the height, you lift the child onto your desk and have them stand tall. OK, between which two points are you wishing to measure?

Is the child's "height" the difference between the top of their head and the floor? How about between the top of their head and the surface of the desk?

Big difference in measurement but both distances are correct, so long as we understand what is being described.

So, voltage is the "push" attempting to move electrons measures between two points. So, just as the height measurement of the child must be understood as being between to specific points, the same is true of the voltage. We must understand where/why the voltage is compared between two points.

I hope to do more on voltage and voltage drop later but let's not oveload too much. Amps. next and then resistance. After that we can beat the three around as Koolaid suggested.

Off to my folks to fix my mother's work light. She's 85 and an avid quilter.

Norm

 

[cowboyup3371]

I second the request about how to know what we can add without killing our charging system. Or, how do we know how much more space we have or if we've gone over already?