To understand the explanation better you need to know the following : 1. A sudden spike in electricity — a power surge — can damage or destroy appliances and gadgets in the blink of an eye. The IC is designed for this very function, stepping down a higher input voltage, to a current controlled LED. Just set it to 500mA, and it will adjust the voltage down until the led load pulls 500mA. The effect of voltage fluctuation in phase-controlled rectifiers with DC-side parameter control is a decrease in power factor and the generation of non-characteristic harmonics and interharmonics. ... and now when my fridge is plugged in, the voltage levels in the whole house change. When the voltage across an insulator gets too high, it is possible that the insulator will stop insulating and will instead start letting some current through. An increase in voltage above an appliance's normal operating voltage can cause an arc of electrical current within the appliance. Some higher end display screens require multiple voltage sources, and failing to power one source to a high enough level, or fast enough, before a second source, can cause damage to the screen or controller. Wouter has some good information, but there are more scenarios where not providing a high enough voltage can damage a device. The line voltage can surge when the current does, spiking the normal 110 volt line with 200 volts or more for brief periods. But when you select the correct laptop charger, please have a look at the following useful methods: 1) Output Voltage is within +/- 5% of your old charger's output. There are cases when the voltage is to high: 250,300,350 and burns most electronic devices. This current flow can cause damage. How can i fix this problem? Depending upon the supply voltage and external components, the PT4115can provide more than 30 watts of output power. I was thinking of putting one electrical fuse of 220V before the voltage enters the house. A 725-watt refrigerator draws 725/120 = 6 amps. Ohm's law : At constant temperature and resistance, voltage is directly proportional to current. The risk of damage is high. ... which will damage appliances and can even cause a fire. The heat generated in the arc causes damage to the electronic circuit boards and other electrical components. One common example of the damage that can be caused by excessive voltage involves the rapid heating – and subsequent cooling – of electrical wiring. Ask Question Asked 3 years ago. However even small voltage surges are capable of causing damage over an extended period of time. And with more electronics in our homes than ever, that can be costly. Possible damaged fridge, low/high voltage throughout the house. In the case of drive braking in an inverter mode, it can result in commutation failure and damage to system components. ie, As the voltage drops, the current decreases. No, it is safe to use the high amperage. Generally though, fractional horsepower motors like the one in your freezer are somewhat more forgiving. Severe voltage surges can damage or destroy most electrical equipment. For example, if your old charger provides 19.5V, then you can use a charger that provides 20.5V or 18.5V. If voltages are high enough, dielectric breakdown can result in arcing, which can cause heating, pitting, etc. Higher voltage than nominal+10% can saturate the magnetic cores of a motor, causing rapid overcurrent and overheating, which exponentially gets worse as the supply voltage is increased. This can happen after blackouts, from lightning strikes, or for other causes. My household circuit has an effective voltage of about 220 volts most of the time (98% of the time). Divide that number by 120 volts, which is the voltage of your power supply, to get the current that the refrigerator draws in amperes.