Are my Amps calculations correct?

[Bert2006]

I am no electrical engineer so here goes.

 

1 x 35 w lamp at 12.8v = 2.734Amps

2 x 35 w lamps at 12.8v = 5.468Amps

 

Is my assumption correct that the amp draw rises for each lamp added to the circuit?

 

Be kind folks....

[uncledj]

Sounds right to me.

Pretty simple math.

Edited January 12, 2014 by uncledj
Didn't look right

[MiCarl]

Your calculations are correct.

 

Depending on what you're trying to figure out you might use a lower voltage.

 

For instance, your 35 watt lamp is going to pretty much use 35 watts regardless of voltage. When voltage is low the amperage will go up. So it's prudent to size fuses and wires for the lowest voltage the system will see, rather than nominal voltage. Sitting at an intersection at idle with the brakes on you probably are below 12.8 volts.

[bongobobny]

OK Watts, or power draw for DC is simply the voltage applied multiplied by the amps drawn at that voltage. Ohm's law is P = I x E where P is power in Watts, I is current or the number of electrons passing a single point per second and is expressed in amperage or amps for short. E is Electromotive force (EMF) which is equal to electrical "pressure" expressed in volts.

 

Now way back when electricity was discovered and studied, Mr. Ohm discovered a relationship between electrical force and flow rate and that they were directly proportional. The more the force (volts) the more the flow (amps). He tied this all together and discovered that there is something that limits or "resists" current flow. He named the units of resistance after himself (or someone else did) and called them Ohms. Now he discovered an inverse relationship between resistance and current flow. By it's very definition the more the resistance, the less the current flow with a constant voltage. To get the same electron flow per second, the more the resistance, the more electrical pressure or voltage is needed. Viola, we have Ohm's law, I = E/R, E = I x R, and R = E/I.

 

Now, as long as the resistance stays the same, such as a filament in a light bulb or a piece of wire, as voltage decreases so does current. What does this mean? When your motorcycle is idling your voltage goes down, the current draw goes down and the light bulb gets dimmer. As you rev up your motor there is more voltage available at the battery, causing the light bulb filament to draw more current making your light brighter. (some of you brighter people will point out that the resistance of the light filament does not stay constant but rather the resistance decreases with lower temperature which increases current flow making a 35 watt bulb stay 35 watts with lower voltage but I disagree, the change is not that significant to equalize it)

 

So what does all of this mean to you? Probably confusion! To answer your question yes the more lights you add the more they will drag down your battery. Try to think of your battery as a storage box for electrons, and the more electrons you take from the battery, the less reserve you have unless you replace those electrons. That is the job of your charging system or the Stator and the regulator/rectifier. They replace those electrons in your electricity storage box, or battery, that you use up listening to music and seeing where you are going and being seen, and using your horn to yell at the idiots in cages.

 

So tell me Bert, what are you trying to figure out??

[Bert2006]

These are my current passing lamps. Once i move to led's i will have .85amp draw for each for a total of 1.7amp.

I will be running them through the Kuryakin Master Cylinder switch unit (3 switches each eated at 10 amps) so I was wondering if that switch could handle the current load. Looks like i am ok for now and more than ok once i go to led's.

Thanks all for helping me validate.

 

Looks like I am good to go.

[bongobobny]

Yup! 10 amp capability will handle 120 to 130 watts no problem. For each lamp you add the watts together to get the total watts...

[Bert2006]

While we are talking about passing lamps. Mine are currently tapped off the headlight as per the standard yamaha instructions with that tiny switch next to the aux plug on the fairing.

 

Will i need a relay when i move them to the Kuryakin switch? If yes where do i include it. The Kuryakin switch has a 30 amp fuse between itself and the battery and then 3 individual 10 amp circuits each with a 10 amp fuse.

 

Thanks again!

[bongobobny]

Well Bert, that is an excellent question, and has more than one answer! Yes, you could just move the wires from the existing switch to the new switch and everything would still work. That being said, you would probably be slightly better off using a relay to turn the lights on and off for a couple of reasons. For one, there will be less of a potential voltage drop across the relay contacts than the contacts of a switch. With higher current going through the switch contacts they can wear out faster and start to loose voltage across the contacts. Relay contacts are a little more heavy duty and will hold up better with time. You can also use a line directly from the battery to the driving lights and have less of a possibility of losing voltage across the ignition switch, etc. Also you can switch the ground on and off on the relay coil instead of switching the 12 volts from the ignition line to the relay coil and minimize the possibility of a short happening in the switch wiring. A relay coil draws a lot less current than the driving lights draw so the switch will last a much longer time.

 

Hope that answers your question...

[bongobobny]

The Kuryakin switch has a 30 amp fuse between itself and the battery and then 3 individual 10 amp circuits each with a 10 amp fuse.

 

Thanks again!

OK each switch has a rating of 10 amps. Three circuits of 10 amps adds up to 30 amps total. Each individual switch has it's own separate fuse so if something happens the other 2 circuits will continue to work. The main fuse for the switch assembly has to be at 30 amps in case something happens to short out the main feed. If you had something lower in value then if all 3 circuits were on and operating at their max rating then everything could be OK but it would blow the main feed. If you had a direct short of the main feed it would draw a lot more than 30 amps which will blow the fuse immediately.

 

Now if you want to know how to hook up the relay, in the previous post I made a slight error in that obviously the Kuryakin unit supplies a voltage through it's contacts so you can't switch the ground on and off to the relay so you must switch the 12 volts on and off to the relay. There are 2 contacts on the relay coil, one for switched 12 volts and one for ground. To supply power to the driving lights there are 2 more contacts, one gets 12 volts from the battery, and the other goes to the driving lights.

 

Now, I need to know if the main power to the switch assembly is tied directly to the battery or to the ignition line. What other things are you going to use the switches for? The reason I ask is if the main power goes directly to the battery and NOT the ignition line, the first time you forget to switch off your driving lights and turn off the bike you will drain your battery to nothing...

[Flyinfool]

Ya, what Bob said.

 

When you do math for lighting systems on your bike use 14 volts. 14 volts is about where things should be while riding. So this will be worst case scenario and also most common scenario.

 

MiCarl

The amps go up as the voltage goes down in an inductive load like a motor. Not in a resistive load like a light.

[bongobobny]

OK response 3. If you just use the switch to supply the driving lights then the wire that is going to the headlight will go to the Kuryakin unit instead and the switch next to the aux plug will be eliminated. In other words, hook up a wire from the new switch directly to your driving lights...

[Bert2006]

OK response 3. If you just use the switch to supply the driving lights then the wire that is going to the headlight will go to the Kuryakin unit instead and the switch next to the aux plug will be eliminated. In other words, hook up a wire from the new switch directly to your driving lights...

 

Ok, so currently the lamps draw their power from the headlight and have a switch to turn on/off.

 

With the Kuryakin as it is wired to the battery, I assume that it is designed to provide power and switch on/off. So I need to disconect the lamps from the headlight circuit and run everything through this new switch....correct?

 

 

I have another set of led lamps on the front forks next to the brakes and my GPS that will be conected to the other two switches on the unit.

 

And thanks again with all the help!!!

[Guest tx2sturgis]

I like to suggest to members here that if they are a bit itimidated by wiring issues, then get a kit for the job. Yep...it'll cost you a bit of time and money, but it will be done correctly. These people make some good wiring kits.

 

 

Click this link, and then scroll down to:

H4 Single with Driving Lights Lead

 

Installation involves running the hot and ground to the battery, and plugging in the H4 at the back of your headlamp. Ziptie everything, and your good to go.

 

The driving lights will be powered either with high beam or low beam, depending on which version you order, and will shut off when the bike is turned off. Also, all headlamp and driving light amperage is handled by the relays, and no longer passes thru the ignition switch. This has the added benefit of possibly making the headlamp just a tad bit brighter.

 

Dual Panasonic relays will probably last longer than the bike, and with one for high, and one for low, each relay is only being engaged about half the time.

Edited January 13, 2014 by tx2sturgis

[csdexter]

I second tx2sturgis's proposal. I made the harnesses myself (because I wanted to plug into the OEM connectors on the bike as opposed to wiring directly to battery) but I got all the parts (connectors, relays, fuses etc.) from the same site and they're very good quality.

 

Bonus, when switching beams I can hear the relays clicking and it's awesome

[Atoolnut]

I have the same kuryakyn switch..I use it to feed passing lamps and my HID..the HID only comes on when I flip the switch not when bike starts..less draw..I wired kurakyn switch using a relay tied into an eastern beaver power block.…then I wired a relay for HID and passing lamps after the switch...maybe a redundant setup but that way no power is on any circuit without being protected by a relay...and no way switch block is live without bike running...did this on my vstar 1100 for 7 years had no problems

[Bert2006]

I have the same kuryakyn switch..I use it to feed passing lamps and my HID..the HID only comes on when I flip the switch not when bike starts..less draw..I wired kurakyn switch using a relay tied into an eastern beaver power block.…then I wired a relay for HID and passing lamps after the switch...maybe a redundant setup but that way no power is on any circuit without being protected by a relay...and no way switch block is live without bike running...did this on my vstar 1100 for 7 years had no problems

 

 

Thanks for that but when installing a relay after the switch for the passing lamps, how is it wired? ie. what connects to what?

[bongobobny]

OK Bert you just opened a can of worms!! Now, as you may or may not know, your passing lamps SHOULD be currently wired to your high beam and switched on and off by the push button switch next to your cigarette lighter. It is done this way so that your passing lamps will not be on with low beams, only the high beams. This was designed so that you don't accidentally blind someone coming from the opposite direction with your passing lamps. So, before we can answer you as to how to hook up your new system we need to know just how you want it to operate. Do you want your driving lights on all the time or only when the high beam is on? Do you want both sets of lights to go on together or do you want them to operate independent of each other (use 2 switches).

 

A relay is actually 2 different circuits. One circuit is the main power that supplies electricity to the device you want to control, and the other circuit is the actual "switch" for the relay. The switch of the relay, normally called the primary circuit of the relay is just a coil of wire wrapped around an iron core, When you apply electricity to the coil it becomes an electromagnet and pulls the contacts of the secondary circuit together completing the connection of the main power to the device you want to turn on or off. Now if you use ignition power for the primary of the relay there is no way on earth that battery power will ever get to the lights without the key being on. The second you turn the key off the relays loose power to the coil and the relay de-energizes regardless of whether the switch is on of off. So, the main power of your Kuryakin switch should go to the ignition line and not directly to the battery regardless of whether or not you use relays on the lights. That way you will NEVER accidentally leave your lights on and kill your battery.

 

My Kuryakin box had a defect from the factory that I fixed. One of the wires got pinched under the cover and when wiggled would blow the fuse. It was where the wires curved under the cover where they get clamped down...

 

Let us know how you want your lights to work and then we can tell you what wire to hook up where...

[bongobobny]

Bert, I may have gotten confused in one of your earlier posts. Are you planning on adding a second set of driving lamps or changing the existing lamps to LED? I may have gotten the impression you were adding more lamps. Anybody that knows me knows I think like a trucker, you can NEVER have too many lights...

[Guest tx2sturgis]

your passing lamps SHOULD be currently wired to your high beam and switched on and off by the push button switch next to your cigarette lighter. It is done this way so that your passing lamps will not be on with low beams, only the high beams. This was designed so that you don't accidentally blind someone coming from the opposite direction with your passing lamps.

 

Lots of good info Bongo, BUT.

 

Passing lamps, by DOT rules, on a motorcycle, legally operate on the LOW beam circuit only and must be controlled by a separate switch. They do not have to be DOT approved lamps.

 

DRIVING lamps, however, can operate on either HIGH or LOW, but must also have a switch to turn them off. They must be DOT approved.

 

FOG lamps should also operate on LOW beam only, and again, be switchable to off.

 

Motorcycles can not legally have more than TWO "headlamps". Any other forward lighting will normally fall into one of the above categories.

 

It depends on what the owner is trying to end up with, there is probably a zero likelyhood of the bike ever failing inspection based on improper passing light or driving light operation...at least here in the states. DOT approval is not the same as state regs, which can vary from place to place.

 

Now, a LEO at the side of the road...who got blinded by the light....now thats a different story altogether.

 

 

 

Edited January 13, 2014 by tx2sturgis

[Bert2006]

Hey sorry for opening up the can of worms.

 

I currently have the accessory passing lamps sold by Yamaha. These take their power from the headlamp circuit but have an on/off switch. I have not checked but they seem to stay on whether I am on hi or low beam (will need to check that one). I also have a set of small led lights on the front forks next to the brake calipers that are tied into the passing lamps. When I turn on the passing lamps, these small led's also light up.

 

What I am doing is converting everything to LED. I will be replacing the current halogen bulb in the headlamp with an led unit and replacing the passing lamps with led units also. I want to separate the passing lamps from the headlight circuit and separate the small led's from the passing lamps.

 

In the end I will have 1 switch for the passing lamps, 1 switch for the small led's next to the front brakes and 1 switch for my GPS.

[Guest tx2sturgis]

What I am doing is converting everything to LED. I will be replacing the current halogen bulb in the headlamp with an led unit and replacing the passing lamps with led units also. I want to separate the passing lamps from the headlight circuit and separate the small led's from the passing lamps.

 

In the end I will have 1 switch for the passing lamps, 1 switch for the small led's next to the front brakes and 1 switch for my GPS.

 

Cool...I bet it will be a sharp looking setup when its all said and done.

 

Make sure the LED headlamp replacement is a full drop in headlamp, not just an H4 LED bulb.

 

One advantage of the LEDs is that with such a small current requirement, you dont have to use relays to power any of them. LEDs are very efficient.

 

Unless you installed a crapload of them, the total current draw for all of them will likely be less then, or about equal to, the single OEM headlamp.

 

You may get some conflicting opinions, but the fact is, that a pair, or two pairs, of 10 or 15 watt LED units can easily be powered with a switch thru the bike's normal electrical fuse panel. I've done it and it works fine.

Good quality LED driving/passing lights always include a voltage regulation circuit to maintain full power even if there is a small voltage drop thru the switch or wiring.

 

[bongobobny]

Good points Brian! With the Kuryakin switch set that he wants to use, the switches send 12 volts out when turned on, so if he wants to use them as passing lamps he will have to use a relay to control them by sending high beam voltage to them, but in his post he says he wants to separate his passing lamps from the headlight circuit. You are correct in the DOT definition and the reasoning being just how the lights are aimed. If the center of the beam drops from center at a distance like low beams do then they are driving lights. I believe it to be 1 foot lower at 25 feet away but I'm not 100% sure. If the beam stays at the same height or higher (can't remember the spec for that) then it is acting like a high beam and is considered a passing lamp.

 

So, once he decides on exactly how he wants his lights then we can advise him exactly how to hook them up. If he wants his passing lamps to function as driving lights then the switch voltage should be adequate as the LED's do not draw that much current that you have to worry about any significant IR drop across the contacts...

[Guest tx2sturgis]

Yep...well its getting kinda technical and all he really needs to know is...how to wire up the darn things.

 

I have to say this...since I've said it in other threads...but it bears repeating here I think.

 

LEDs work pretty well...but I dont think the LED Headlamps are quite up to where they need to be...yet. I'm sure they will get there. Technology is improving all the time.

 

My main gripe I suppose, is how fugly they are when turned off. My gawd they look like some kind of overgrown mutant insect eyeball from a sci-fi flick. Sorry...they just DO.

 

I MUCH prefer the Hella E-Code lighting. A new one with a good H4 bulb is a lot better than the stock headlamps on most motorcycles sold in the US.

 

It's perfectly legal in the USA to run an E-Code headlamp on a motorcycle, and the broad, bright white pattern is a wonderful thing to behold at night from the rider seat. Plus, they look damn good even turned off!

 

You can buy 4 of them with bulbs for the price of ONE LED headlamp.

 

It's a no brainer to me....but I recognize that not everyone has the same taste as me....much to my amazement.

 

There...its off my chest....carry on.

 

 

 

 

 

 

 

 

[Bert2006]

Here is the led headlight bulb I ordered. Taking a risk that it actually works as advertised. Will let you know.

 

http://canadiancruisercustomizing.com/products/afterburner-led-headlight-direct-replacment-lamps

 

 

Thank you so much for all of the comments on this thread. It got a bit technical for me but here is what I got out of it. Hopefully it makes sence.

 

The Kuryakin 3 swich unit will be wired to the battery with a 30 amp fuse. One switch will then power the passing lamps with a 10 amp fuse. One switch to power set of Bikevis bullets attached to the front brake caliper bracket with a 2 amp fuse Third switch to power the gps with a 2 amp fuse. All lights are leds so switch should be able to handle without a need for relay.

[Guest tx2sturgis]

Here is the led headlight bulb I ordered. Taking a risk that it actually works as advertised. Will let you know.

 

 

First, the good news. It looks like a quality unit and should work as a 'customization'...but the 'fan' part worries me a bit. A fan? I remember the days long gone....sitting in 4th grade science class...and the movie and slide projector bulbs were fan-cooled...and burned out often. If the fan quit, the film burned up.

 

 

Now the bad news: It probably will not be much of a headlamp when you need it most.

 

A good replacement LED headlamp will cost about $200....give or take.

 

Promise that you will come back and let us know how it works out for you. I want the report from the guy who owns one.

 

Good luck sir.

 

 

 

Edited January 13, 2014 by tx2sturgis