Been reading through several threads here about connecting up non-factory headlights and I see the term "wattage" thrown around a lot. As though you can take something that is of similar wattage and just connect it without knowing the other variables involved in the circuit.
Wattage is not set value when it comes to electronics as it can change based upon other values involved. Please review the Ohm's law diagram.
Wattage is generally calcuated based upon knowing the current and the voltage of the circuit. So let's look at a basic example for those of you that aren't into electronics.
Your average hair dryer is 1500W, and in the US it would be running off a 120VAC circuit.
1500W / 120VAC = 12.5Amps
But in Europe and other countries, they use 220VAC
1500W / 220VAC = 6.8Amps
Increasing the voltage supplied lower the current drawn. Running devices in your home on 220VAC is more efficient as it draws less current. Less current, less heat.
Now in the cases of headlights I'm seeing lots of values being thrown around without much consideration as to how much current is actually going to be drawn in the circuit. The headlight circuit in the controllers doesn't supply much, and if you connect something in there that's going to draw more than it can supply you'll quickly burn out the voltage regulator for that part of the controller. Unless you're really handy with a soldering iron and trouble shooting circuits, you'll be buying a new controller.
Let's do some math, cause math is fun.
You buy a headlight that's an 18W, but it needs 12V to function.
18W / 12V = 1.5A
What if the circuit only supplies .5A or 500mA? You just tripled the amount of current the circuit needs to supply. It will work, but only for a little bit before the magic blue smoke is released.
Part of the problem in figuring these things out is what voltage and how much current the headlight circuit is designed to supply. You can measure the voltage with a standard multimeter and that will give you a start, but unless you can get the manufacturer to tell you how much current the circuit was designed to supply you're just kind of guessing. And when you're guess, it's best to guess low.
Let's got back to our 18W light.
18W / 36V = .5A which fits into our example from above.18W / 48V = .375 which again would fit.
You need to know the voltage that the light circuit is supplying before you can make any kind of proper guess if it's going to work without burning out the circuit.
Most everything in electronics can be expressed as a math equation, even horsepower. 1Hp = 745W, so your 1500W hairdryer is a little more than 2Hp.
How many horsepower does your average horse supply? Between 20 and 25hp.
Please before you start hooking random lights up to your bike's controller, take some time to measure voltage of the circuit and do the math. You do not want to release the magic blue smoke of your controller. Once it's released you can't put it back in.
Wattage is not set value when it comes to electronics as it can change based upon other values involved. Please review the Ohm's law diagram.
Wattage is generally calcuated based upon knowing the current and the voltage of the circuit. So let's look at a basic example for those of you that aren't into electronics.
Your average hair dryer is 1500W, and in the US it would be running off a 120VAC circuit.
1500W / 120VAC = 12.5Amps
But in Europe and other countries, they use 220VAC
1500W / 220VAC = 6.8Amps
Increasing the voltage supplied lower the current drawn. Running devices in your home on 220VAC is more efficient as it draws less current. Less current, less heat.
Now in the cases of headlights I'm seeing lots of values being thrown around without much consideration as to how much current is actually going to be drawn in the circuit. The headlight circuit in the controllers doesn't supply much, and if you connect something in there that's going to draw more than it can supply you'll quickly burn out the voltage regulator for that part of the controller. Unless you're really handy with a soldering iron and trouble shooting circuits, you'll be buying a new controller.
Let's do some math, cause math is fun.
You buy a headlight that's an 18W, but it needs 12V to function.
18W / 12V = 1.5A
What if the circuit only supplies .5A or 500mA? You just tripled the amount of current the circuit needs to supply. It will work, but only for a little bit before the magic blue smoke is released.
Part of the problem in figuring these things out is what voltage and how much current the headlight circuit is designed to supply. You can measure the voltage with a standard multimeter and that will give you a start, but unless you can get the manufacturer to tell you how much current the circuit was designed to supply you're just kind of guessing. And when you're guess, it's best to guess low.
Let's got back to our 18W light.
18W / 36V = .5A which fits into our example from above.18W / 48V = .375 which again would fit.
You need to know the voltage that the light circuit is supplying before you can make any kind of proper guess if it's going to work without burning out the circuit.
Most everything in electronics can be expressed as a math equation, even horsepower. 1Hp = 745W, so your 1500W hairdryer is a little more than 2Hp.
How many horsepower does your average horse supply? Between 20 and 25hp.
Please before you start hooking random lights up to your bike's controller, take some time to measure voltage of the circuit and do the math. You do not want to release the magic blue smoke of your controller. Once it's released you can't put it back in.