Remote compressor wiring.

[Flyinfool]

OK you guys that know the electrical of a first gen inside out.

 

I am thinking about mounting an air tank and compressor in one of my saddle bags on a 1st gen.

When running, the compressor will pull 16 Amps.

It should never have to run for more than 2 minutes, typical run time is 30-45 seconds. I hope it will not need to run more than once a week, once the novelty wears off.

 

Will the electrical system handle this?

 

If not;

I was thinking of installing a secondary battery with a SPDT relay so that the bike electrical system will never have to power the compressor. The extra battery would be connected to the com term of the relay and the compressor will be on the N.O. side with the bike power for charging on the N.C. side. The coil would be wired in series with the secondary battery and the pressure switch (through a relay) to refill the tank.

 

 

The bike will still be able to charge the secondary battery when it is running, but the relay would isolate the compressor from the bike.

The small 7Ah battery that I was going to use is plenty to refill the 1/2 gallon air tank 7 - 10 times before it needs a charge.

 

My question is, how much extra load will be on the bikes electrical system while charging the battery?

If charging the extra battery can/will end up pulling just as much power as the compressor then it makes no sense to add all of the extra complication.

 

Does any of this make sense?

Any other ideas of how to safely power the compressor without risk to the R/R or stator.

 

This is most likely next winters project so I have a lot of time to work on the plan.

[Squeeze]

You can easily calculate DC Currents. Voltage is Current multplied with Resitance, Power is Voltage multiplied with Current.

 

16 Amps and one Hour continous running Compressor will take the Amount of 16 Ah out of your Battery. The stock Lead Acid Battery is 20 Ah, so 16 Ah will discharge the Battery too much. You should not drain the Battery down to less than 25 Percent of it Capacity to save Battery Life. Having the same Battery starting the Bike after running the Compressor is hard to say, depends on the Conditon of the Battery. I'd say your safe to start the Bike at 45 Percent of the remaining Battery Capacity when the Motor is not hard to start.

 

50 Percent of a fully charged Battery is 10 Ah, which means you can draw 10 Amps for one Hour or 20 Amps for 30 Minutes. 16 Amps draw would mean 0.625 Hours or better said 37.5 Minutes. This is all calculated with steady Voltage, which isn't the Case, the Voltage drops while the Battery delivers its Current, so you have to take this into Calculation too. Again, this depends also on the Battery Condition.

 

To make that long Story short, the Compressor won't harm the Battery when you run it up 20 Minutes with the Engine stopped. The Charging System isn't in overload under these Circumstances too.

 

Your best bet would be looking for a Battery Safer Relay. These are used in Trucks and RV's to secure the Battery from complete Drain and premature Death. If you could choose the Discharge End Voltage, I'd look for a 11.0 Volts Relay, most common are (Refrigarator) Relays at 10.8 Volts.

 

I'd do some on Shop Site Tests before switching this in public up and running Mode, hooking up a DMM direkt to the Battery and checking Time as well as Battery Voltage and Ability to start with the remaining Capacity.

[Flyinfool]

I was not worried about the battery handling the load.

There is plenty of safety margin in there.

 

My concern was putting an additional 16A load on the electrical system of the bike while going down the road. Granted I will be putting on a VERY intermittent load. I am guessing about 1 minute per week (if I can get a leak free system).

It is my understanding that the stock charging system is rated for ~30A. I keep reading the tails of adding a pair of 55W driving lights at 9.2A getting things pretty close to the edge of the charging systems capability along with the electrical demands of the rest of the bike. I do not have the driving lights but do have about another 3A worth of LEDs. The more often that the charging system has to run at max capacity, the shorter its life will be.

 

The more that I think about it, as long as I have a relay so that the compressor can never run when the bike is not running so that an air leak would not leave me with a dead battery. It should be OK.

 

I guess that being old means that everything has to be overkill, good enough is never good enough. I might be trying to over think this again.

[Sylvester]

Just mount the tank and no compressor. It should do fine without recharging up to a point. Recharge at the home when needed. Unless you need an awful amount of air.

 

[Marcarl]

So why do you need all that air,,,,inquiring minds need to know,,,,actually, I'm just being nosey.

[MiCarl]

I... The more often that the charging system has to run at max capacity, the shorter its life will be...

 

Not so.

 

The alternator always runs at max capacity. Excess is shunted to ground by the voltage regulator. If anything, extra load reduces the work of the voltage regulator.

 

If you run the compressor for 2 minutes you'll use .533 amp/hours. Equivalent to running a pair of 55w driving lights for 3.5 minutes.

[Flyinfool]

So why do you need all that air,,,,inquiring minds need to know,,,,actually, I'm just being nosey.

 

I knew someone would ask........

 

This is what I am working on a way to hook up to the compressor.

 

 

 

Not so.

 

The alternator always runs at max capacity. Excess is shunted to ground by the voltage regulator. If anything, extra load reduces the work of the voltage regulator.

 

If you run the compressor for 2 minutes you'll use .533 amp/hours. Equivalent to running a pair of 55w driving lights for 3.5 minutes.

 

It was my understanding that the regulator is a linear regulator that works by taking any excess voltage and turning it into heat. That is why the after market "HD" regulators come with a great big finned heat sink. the more amps that you pull the more heat you make till you get high enough amps that the stator can no longer keep up and you pull the voltage of the stator down so that there is not as much voltage to drop. The power that the regulator must deal with is;

(Stator output voltage - 14.0 Regulated output voltage) X Amps.

So as the amps go up the heat in the regulator also goes up.

 

Like I said that was my understanding of how the system works, there are other ways to regulate voltage and I may very well have guessed wrong.

I will have to do some testing to see if I can tell for sure what type of system is there.

IF the system did actually run the stator at full power all of the time and dump the excess to ground, then the regulator input amps will be more than the regulator output amps. (least efficient type of regulation)

If it is a linear regulator then the input amps will equal the output amps of the regulator. (inexpensive reliable regulation)

If it is a switching regulator (would be nice but I doubt it) then the regulator input amps will be less than the output amps. (Most expensive and most efficient type of regulation)

 

Time to do some testing.

[MiCarl]

I'm only aware of two types of regulator/alternator systems:

 

1) Field Coil. The magnets in the alternator are electromagnets. The regulator adjusts the alternator output by changing the power to the electromagnets, thus increasing/decreasing the magnetic field. The regulator typically does not generate a lot of heat. The Venture does not have this type.

 

2) Permanent magnet. The magnets in the alternator are permanent magnets (like a bar magnet from your science class). The power produced is only dependent on the RPM because the magnetic field is constant. Voltage is regulated by the regulator shunting excess power to ground (converting it to heat). Cooling fins may be used to dissipate the heat. This is the type of alternator on the Ventures.

 

You'll notice that I did not use the terms volts or amps when discusing the alternator. I used the term "power" which is measured in watts. Alternators produce power, the voltage is dependent on the load which is measured in amps. We sometimes get lazy and talk about amps because we assume the voltage is always 12 (more or less) when talking about motorcycles.

 

In reality your alternator is rated at roughly 360 watts (12 volts X 30 amps). It'd quite happily produce 20 amps at 18 volts (20 X 18 = 360 watts).

 

If you're up in the RPMs (the alternator peaks in the 5,000-6,000 RPM Range) the alternator is producing 360 watts. If you're motorcycle and it's accessories have a load of 20 amps it's consuming 240 watts. That leaves 120 watts unused. That can't happen because electrical systems have to be in balance. In reality the alternator would push the voltage up to 18 volts so that your 20 amp load is using 350 watts of power (18 volts X 20 amps). To keep the voltage down the regulator adds a 10 amp load by shunting power to ground. Since the load is 30 amps (using 20, 10 added by regulator) the system balances at 12V.

 

Anyhow, it's the amps you DON'T pull that are converted to heat by the voltage regulator.

 

I haven't heard the word "linear" in use with a regulator. Modern voltage regulators use zenier diodes which I suppose are linear in nature. Old regulators were electromechanical and switched rapidly between no load and infinite load (the battery acts as a damper).

 

This can all get confusing because the rectifier is contained in the same box. It performs a separate function though, and on older motorcycles it was often a separate component.

 

Incidentally, this is why you should not jump your motorcycle with a running motor vehicle. Car and truck alternators are capable of driving 60 amps or more at 12V (720 watts). Your poor little regulator could burn up trying to shunt the extra power off.

[Guest seuadr]

why not save all that work and just buy some high decible electromagnetic horns? no air tank required..

 

[ame=http://www.amazon.com/Stebel-Magnum-Motorcycle-Horns-Electromagnetic/dp/B000TK3UOE]Amazon.com: Stebel Magnum Motorcycle Horns - Dual Tone - Electromagnetic - Chrome: Automotive@@AMEPARAM@@http://ecx.images-amazon.com/images/I/51Z7OS735rL.@@AMEPARAM@@51Z7OS735rL[/ame]

[dingy]

I think running the compressor is not the issue.

 

Where you going to mount the horns.

 

Ad says longest on is 20" long & 5" diameter bell.

 

And there are 3 more smaller ones.

 

 

Gary

[Flyinfool]

In comparison those electric horns are pretty wimpy.

 

Gary

You are correct, finding a good place for the horns is the hard part.

Maybe I will have to chrome them and not try to hide them.

[Guest seuadr]

In comparison those electric horns are pretty wimpy.

 

Gary

You are correct, finding a good place for the horns is the hard part.

Maybe I will have to chrome them and not try to hide them.

9 decibles isn't very much of a difference

Edited April 11, 2010 by seuadr

[dingy]

Gary

You are correct, finding a good place for the horns is the hard part.

Maybe I will have to chrome them and not try to hide them.

 

You haven't got a snowballs chance in heck of hiding a 20" long 5" diameter horn on a first gen.

 

I might fit in the saddlebag, kinda hard to hear in there though.

 

Could put compressor setup in one saddlebag and drill other saddlebag and let the bell end of horns stick out front.

 

 

Gary

[Guest HotMech]

I'm only aware of two types of regulator/alternator systems:

 

1) Field Coil. The magnets in the alternator are electromagnets. The regulator adjusts the alternator output by changing the power to the electromagnets, thus increasing/decreasing the magnetic field. The regulator typically does not generate a lot of heat. The Venture does not have this type.

 

2) Permanent magnet. The magnets in the alternator are permanent magnets (like a bar magnet from your science class). The power produced is only dependent on the RPM because the magnetic field is constant. Voltage is regulated by the regulator shunting excess power to ground (converting it to heat). Cooling fins may be used to dissipate the heat. This is the type of alternator on the Ventures.

 

You'll notice that I did not use the terms volts or amps when discusing the alternator. I used the term "power" which is measured in watts. Alternators produce power, the voltage is dependent on the load which is measured in amps. We sometimes get lazy and talk about amps because we assume the voltage is always 12 (more or less) when talking about motorcycles.

 

In reality your alternator is rated at roughly 360 watts (12 volts X 30 amps). It'd quite happily produce 20 amps at 18 volts (20 X 18 = 360 watts).

 

If you're up in the RPMs (the alternator peaks in the 5,000-6,000 RPM Range) the alternator is producing 360 watts. If you're motorcycle and it's accessories have a load of 20 amps it's consuming 240 watts. That leaves 120 watts unused. That can't happen because electrical systems have to be in balance. In reality the alternator would push the voltage up to 18 volts so that your 20 amp load is using 350 watts of power (18 volts X 20 amps). To keep the voltage down the regulator adds a 10 amp load by shunting power to ground. Since the load is 30 amps (using 20, 10 added by regulator) the system balances at 12V.

 

Anyhow, it's the amps you DON'T pull that are converted to heat by the voltage regulator.

 

I haven't heard the word "linear" in use with a regulator. Modern voltage regulators use zenier diodes which I suppose are linear in nature. Old regulators were electromechanical and switched rapidly between no load and infinite load (the battery acts as a damper).

 

This can all get confusing because the rectifier is contained in the same box. It performs a separate function though, and on older motorcycles it was often a separate component.

 

Incidentally, this is why you should not jump your motorcycle with a running motor vehicle. Car and truck alternators are capable of driving 60 amps or more at 12V (720 watts). Your poor little regulator could burn up trying to shunt the extra power off.

 

Be afraid, be very very afraid. People here would like you to believe, that they know more than the electrical engineers, that desighned all this. I am done trying to educate the less informed, as well as the Know-it-all's. You can be scared of electricity, or you can understand it. So far, all I see here is the scared. There is no danger in "Jumpstarting" a Motorcycle with a car, or truck, Running or not! Period! On the other hand, you should not leave an automotive sized battery connected to a M/C charging system for more than just a jump, that sized battery can and will draw up to and beyond the charging capacity of our bikes. You can safely charge a M/C battery with a cars running charging system. That battery will only draw what it needs to charge. A 110 volt shop sized battery charger will and can overcharge any battery. It is not voltage regulated, but current regulated. These are the facts folks. It is science, after all.

[dingy]

On the other hand, you should not leave an automotive sized battery connected to a M/C charging system for more than just a jump, that sized battery can and will draw up to and beyond the charging capacity of our bikes.

 

I really don't think you know what you are talking about.

 

You contradict yourself and your limited knowledge by the above clip of your rant. You say that you can jump a motorcycle from a running car, but don't leave it on there or it will overdraw.

Are you aware of the speed of electricity?

 

Ever seen lightning. It's pretty fast.

 

Heat will destroy almost any electronic component. Especially those with solid state components (P-N junctions).

 

Current equals heat.

 

The clamping circuit of a motorcycle regulator is not designed to handle the in rush current from a 100 amp alternator. The rectifier/regulator does indeed draw this current from the host vehicle, it is not that intelligent of a circuit, all it knows is there is more of a supply of electrons than needed, so it performs its designed for purpose and shunts those extra electrons to ground before they can overcharge the battery. This is the regulators purpose.

 

If a very high potential source of electrons are made available, the rectifier will instantly begin shunting these to ground.

 

Trust me when I say that the Japanese did not over design the electrical components on this bike.

 

Ever notice all the heat fins on the regulator/rectifier on a venture. Those are not for aerodynamics, they are there to bleed off the the woefully small, but excess current the puny generators on these bike put out. That bleed off produces heat.

 

The reason a running car will produce damage when a large battery will not is voltage.

 

A battery has a steady voltage. An alternator produces an increasing voltage.

 

This is all not to imply that this will mean instant death for every motorcycle that is jump started from a running car though. Even a blind squirrel gets lucky and finds a nut now and then.

 

I will take you at your word that you are done trying to educate us.

 

Gary

Edited April 11, 2010 by dingy

[Guest HotMech]

It's painfully obvious, that I can't help you people at all.

 

It's also very clear to me, that I am not going to recieve any help here.

 

Both of which are the reasons I joined.

 

I give up! Freebird, You can keep the dues.

 

I have had enough of these forum things.

 

Totaly pointless, from where I stand.

 

Goodbye.

[Flyinfool]

9 decibles isn't very much of a difference

 

9 dB is a BIG difference, for every 3 dB the sound pressure doubles. That meas that 9 dB louder is ~8 times louder. Decibels are measured on a logarithmic scale so a small numeric change makes a big difference.

 

The Stebels are measured at 4 inches. Sound pressure is cut in half every time you double the distance. A db reading without a distance is a totally meaningless number. That is like saying that my car does 125 without specifying mph or kph. You also need to know which scale the db as being measured on. There are a lot of ways to make dbs lie for those that do not understand them. Unfourtunatly There are very few horn makers that give enough info to make an educated decision.

Look at the specs for the Stebel horns (page 4 bottom of page), they are one of very few horn makers that give accurate info about their horns, Notice their dB spec, 139 dB(A) at 4 inches and already down to 115 dB(A) at 2 meters.

 

I used to work as an engineer for Prime Manufacturing, one of the products that we made was Horns for locomotives. The spec that we had to meet was 125dB(A) at 100 yards. That is LOUD. Most of the "train horns" that you can get aftermarket are not up to the task of 125 db at 100 yards, but are still a lot louder than something measured at 4 inches. The biggest problen with installing a train horn on a road vehicle is the air supply, It is hard to supply 120 psi @ 30cfm to get full rated volume.

[Squeeze]

It's painfully obvious, that I can't help you people at all.

 

It's also very clear to me, that I am not going to recieve any help here.

 

Both of which are the reasons I joined.

 

I give up! Freebird, You can keep the dues.

 

I have had enough of these forum things.

 

Totaly pointless, from where I stand.

 

Goodbye.

 

I'm sorry to hear you're about to leave, but it's your Choice. You do whatever you have to do.

 

On the other Hand, Dingy IS electrical Engineer and i myself got educated in that Area too. I stand right behind him in this Matter.

 

He's also right in saying you contradicted yourself in your Posting and, as opnionated as we all are, sometimes it better to listen to others and think about what they have to say, think about this and what you learned and gather a better Knowledge over all.

 

I'm not talking about your Choice of Words either. We all might be wrong sometimes, but using the Words "be afraid, be very afraid" sounds a Bit like Overkill to me.

[Guest seuadr]

I'm sorry to hear you're about to leave, but it's your Choice. You do whatever you have to do.

 

On the other Hand, Dingy IS electrical Engineer and i myself got educated in that Area too. I stand right behind him in this Matter.

.

 

i admit that i don't have much experence with DC electricity, other than this hobby, and ECM motors, but the principle is the same as with AC. I have to agree with squeeze and dingy, it's a matter of physics.

[Flyinfool]

WOW

I really had no intention of opening such a big can of worms here.

This charging system issue apparently is as bad as politics and/or religion.

 

I realize that there are certain myths about electricity that have been repeated so often that they have become gospel to some, and each camp has its follerers, and will not be convinced by mere facts. Notice that I have NOT said which camp I am in at this point but believe me I am in one. I will listen to any theory that can be backed up with physical measurements.