Can using a lower volt power supply fry a light?

[Biglew11]

I'm ok with thinking this way it's a very common misconception/wives tale. A lot of people think believe it, but many people are wrong about a lot of things.

Ohms law is a misconception/wives tale?
I did this for a living.

 

[Brew12]

devices (load) plugged into a power supply will try draw the same wattage no matter what! if the power supply voltage decreases it has to output more current if it is able to. you risk burning out either the power supply (source) if it is unable to supply the current. or burning out the device (load) if its circuits cant handle the current.
the kessil a360we is a 90 watt light it will try to draw 90 watts on the 19 volt power supply it will draw 4.73 amps
on the 12 V power supply it was trying to draw 7.5 amps.

Sorry but wattage will decrease with voltage and thus current. The led lights will burn at half wattage and a much lower current. If you you were correct guys who fly model aeroplanes would burn their components as battery voltage decreases, but they do not, voltage, prop speed and current all decrease.

You guys are actually both correct, and without knowing how the circuit board is set up I can't say for sure which is applicable for this application.
For many loads they will draw their rated power and is true of all almost all induction and synchronous motors. As voltage drops, current goes up to compensate. For purely resistive loads, if voltage drops the current will also drop. With electronic circuits, it could go either way. Many electronics are designed to use an input of anywhere from 48VAC to 240VAC and use a regulator built into the device to maintain constant power. The current going into the electronics will change based on voltage, but the output will be constant voltage and current regardless of what the input is doing.
If this is how the Kessil is set up, then yes, using a power supply that doesn't offer enough voltage can cause damage to the circuit board as it tries to regulate the output.

 

[Biglew11]

You guys are actually both correct, and without knowing how the circuit board is set up I can't say for sure which is applicable for this application.
For many loads they will draw their rated power and is true of all almost all induction and synchronous motors. As voltage drops, current goes up to compensate. For purely resistive loads, if voltage drops the current will also drop. With electronic circuits, it could go either way. Many electronics are designed to use an input of anywhere from 48VAC to 240VAC and use a regulator built into the device to maintain constant power. The current going into the electronics will change based on voltage, but the output will be constant voltage and current regardless of what the input is doing.
If this is how the Kessil is set up, then yes, using a power supply that doesn't offer enough voltage can cause damage to the circuit board as it tries to regulate the output.

This is also dependant on where the power is coming from. Batteries have a limited supply. They are only able to provide a finite supply. A transformer plugged into the wall is essentially unlimited.
In respect to a battery source as the battery drains, its available voltage and current will drop. Wich is why there is no harm to electronics when a battery dies.

In respect to a transformer in the wall if the transformer is able to supply the current, and the device is trying to draw the same wattage, if the volts go down the current will increase.

You need to pay close attention to what the source of your power is, to figure out if low voltage may be a problem.

I'm not sure what kind of regulators are on the kessil. But yes a lot of electronics are designed to run on a wide range of voltages.