The relationship between voltage, current, and resistance forms the idea of the famous Ohm’s law. When the voltage in a linear circuit with a fixed resistance increases, the current surges. And, when we reduce the voltage, the current decreases. This article will explain how voltage decreases when current increases and other related information.
Why Voltage Decreases When Current Increases?
According to Ohm’s law, The voltage across a conductor is proportional to the current flowing through it. However, the voltage on a transmission line is not the same as the voltage across the line. The multiplicative product of transmission line voltage and current must be constant for the given power output.
As a result, when the power is held constant, an increase in voltage causes a drop in current flow.
In other words, if resistance and temperature remain constant, an increase in voltage causes the current to rise. When power remains constant, an increase in voltage reduces the current.
Things that happen when the supplied voltage is not high enough
If the supply voltage is too low, two things could happen:
- Power usage will be lower than typical if we run the appliances without boosters or stabilizers. However, this will result in poor equipment performance and may even cause harm to the equipment.
- Using a booster or stabilizer to power our appliances would increase power consumption due to booster losses. Also, because rated power is being drawn at low voltage, there will be a further voltage drop, implying a larger current drain from supply lines.
How does maintaining the same level of power affects voltage & current?
The expenditure of an amount of energy over a certain period is something referred to as power. To maintain the same power level, either the voltage or the current must fluctuate. The voltage and current are inversely proportional to each other, and the speed of electrons is analogous to voltage.
When a tiny number of electrons move through a wire, they travel at a rapid speed and pass through with no resistance.
However, when the number of electrons traveling through a wire increases in proportion to the voltage, the interior surface of the wire loses its smoothness due to an exponential increase in friction. Since electrons have the same charge, they tend to repel each other, resulting in higher resistance. The current flow across the wire will eventually be reduced as a result of this. This is known as power dissipation.
Power Dissipation: Is It Normal?
In all fields of electrical engineering and not just electronics, power dissipation in circuits is a fact of life. Power dissipation in resistors is thought to be a natural occurrence. The truth remains that any resistor in a circuit with a voltage drop across them will dissipate electrical energy.
Because electrical power is converted into heat energy, all resistors have a power rating. A resistor’s power rating is also a categorization that specifies the maximum power it can dissipate before critical failure.
Dissipation of Power in Storage Devices:
Beginners erroneously try to figure out the power dissipation of two components. Remember that ideal capacitors and inductors are power storage devices, not power dissipators.
While capacitors and inductors occasionally have voltages across them and the current flowing through them, they are charging or discharging, and hence no power is lost. This is the ideal scenario as described, and reality differs from it. In practical terms, they have a series of resistance that causes a minor amount of power loss but can usually be overlooked.
Power Dissipation| Beneficial or Harmful?
Power dissipation is harmful since it results in a loss. However, there are some situations in which heat dissipation is beneficial. Electric heaters that use resistance wire, such as Nichrome, are exceptions.
Undoubtedly, Nichrome is a one-of-a-kind heating element because of its cost-effectiveness, resistance to electron flow, strength, flexibility, oxidation resistance, and stability at high temperatures.
Incandescent light bulbs, which are used as cost-effective heaters, are another example where heat dissipation is beneficial. Under most conditions, heat dissipation is undesirable.
There are some points to know about power dissipation:
- Ensure that the power rating of your resistor corresponds to the requirements of your circuit design.
- Double-check whether your IC rating is reliant on the heatsink used.
- When building PCBs, make sure your traces are large enough to keep resistance low and prevent overheating.
- When designing a switching circuit, keep the switching time as quick as feasible.
- Furthermore, reduce the capacitance on the line to make the slew rate as steep as feasible to reduce switching times.
The field of electronics describes slew rate as the change in current, voltage, or other electrical measures within a unit of time.
Ways In Which You Can Reduce Power Dissipation
By dynamically stopping the clock pulse from reaching a set of sequential state elements, this technique minimises power consumption in a power-on domain.
Multiple power domain blocks can be used where each power domain block can be powered up or down independently by managing the power switches that gate the power supply connection.
Multiple supply voltages:
Each power domain block is connected using level shifters, and different supply voltages are delivered to different power domain blocks depending on operating conditions which can reduce power dissipation.
The clock signal is responsible for the majority of the power dissipated in synchronous circuits. By removing the clock and replacing it with a handshaking mechanism, the overall power dissipation is reduced to its minimum.
Low Power Cell or State Retention Cell:
The ability of state retention registers (SRR) to retain their state after the power domain is turned off can reduce power dissipation.
Isolation cells are used to separate the power off and power on domains, ultimately controlling the power dissipation.
Power switches are extensively employed in modern low power designs to prevent power dissipation, particularly leakage power dissipation that is caused by technology scaling. Different portions of the design are outfitted with one or more power switches to provide power gating functionality.
Effects of Low Voltage on Electricity Bill:
The voltage-current pair (power) product is given priority when computing the electricity bill based on the amount of power used at any particular time. The calculation of our full electricity bill now takes place using the kilowatt hour.
Have you ever considered the impact of low voltage on your electricity bills? So, if you think that low voltage will lead to low electricity bills, then you are wrong as that’s not the case.
Each gadget has a different voltage rating. Normally, the gadgets can only operate at full capacity when the rated voltage is applied. However, if the voltage drops, the electricity bill will remain unchanged because the electricity cost is not based on volts. The amount of electrical energy determines it turned into other energy by the gadget at any particular time.
Assume that you have a table lamp with a power rating of 28 watts and a voltage rating of 220 volts that is left on for 5 hours with extreme caution. We’ll now compute the electricity cost for these three hours. Because the table lamp has a power rating of 26 watts and a voltage rating of 220 volts, it will require current = 28/220 = 0.1273 amperes. The output power, in this case, comes out to be 0.1273 x 220 = 28 watts. Because the lamp lasts three hours and the cost of power is assumed to be 6 dollars per unit, the bill will be 28 watts x 5 hours = 140 watt-hours / 1000 = 0.140 kilowatt-hours x 6 dollars = 0.84 dollars.
Can low voltage harm household appliances?
Yes, low voltage heats up different appliances to a certain level, which can be harmful. Every appliance necessitates some level of power. Consider a situation in which the voltage is substantially lower than the required. What will occur?
If the voltage is low enough, the appliance will require additional current to reach its rated power. As the current in the conductor grows, so does the amount of heat produced. The higher the current flow, the lower the voltage, and the more heat generated, which may burn the wire, insulate, and harm your home appliances.
How do you boost your end voltage?
Shunt capacitors can be connected to generate and feed reactive power to the load in order to enhance the voltage at the receiving end. This allows the reactive power to flow across the line and reduces the voltage drop in the transmission line.
Which is riskier; high voltage-low current or low voltage-high current?
High voltage poses a greater risk than high current. Let’s look at an electric shock as an example. The human body functions as a resistor because current flow, whether high or low, requires some potential difference to pass through it. Our bodies can often tolerate a voltage differential of 50–60 volts.
As a result, we experience electric shocks of potential difference rather than high current. Although increasing current can have a severe effect, it has little effect if the potential difference is less than 60 volts.
What causes a house to have low voltage?
The gadgets you use daily require a smooth, consistent and undisturbed flow of electricity. On the other hand, Voltage fluctuations can harm both the electrical supply and the appliances.
It’s important to know the reasons behind these fluctuations because once you know what’s causing them, you can take precautionary measures to save your appliances.
Below we have mentioned some of the most common reasons that can cause a surge in a home or office:
Voltage fluctuations might occur if your location or residence has a weak electric supply. This damage might be caused by any loose connection in the electrical supply lines.
Furthermore, if the transmitter installed in your house is of a limited capacity, it’s most likely to cause a poor electrical supply.
This is yet another cause of voltage surge. If the wiring in the building is not properly built, the cables may not be able to hold the necessary quantity of power. Furthermore, bug infestation might damage the cables, causing the voltage to fluctuate.
Voltage fluctuations might occur if there is an impedance in the transmission lines. Natural causes of obstruction include lightning, severe rains, damaged power lines due to fallen branches, and so on.
Ways to Prevent Voltage Fluctuation in Home Appliances
1- Voltage Stabilizer Installation
Stabilizers are specifically designed to check the changes in the power pressure. Whenever there’s a voltage surge, these stabilisers only supply the amount of current that is vital for running an electric device.
If you believe that voltage fluctuations are very common in your area and it can harm your appliances, nothing is better than a good quality stabiliser. it’s the best way you can keep all the appliances in your house safe.
2- Surge Protector Installation
A surge protector is a small device that is often installed for two main purposes. The first is to plug several devices into one power outlet. However, the second purpose is the more important one, and that is to prevent the appliances or gadgets from being affected by the high-voltage surge.
When you install such a device, you can actually protect any electrical device in your house from any unwanted and sudden electrical damage. A surge protector can divert an unusually high-voltage surge and prevent an electrical fire. As a result, you can keep your appliances safe and save money at the same time.
3- Fix the Wirings
Sometimes, people tend to ignore the old or troublesome wirings in their houses. However, it’s important to note that a single damaged wire can cause bigger damage.
If you have been ignoring this, ensure that you get the wirings fixed as soon as possible. This is to ensure that your home appliances and other gadgets stay safe!
So, if you notice any problem such as a burning smell or electrical sparks coming out of a power outlet, you should call a professional to help you out with this issue right away.
4- Unplug All Your Gadgets During Thunderstorms
Do remember this fundamental guideline for protecting your appliances from voltage surges. Never plugin or use any of your electrical gadgets while there’s a thunderstorm happening. It’s always a great idea to unplug all the gadgets and keep them safe from an electrical surge.
5- Use Of Additional Power Protection
Some household equipment like refrigerators, computers, electric ovens and televisions are extremely sensitive. In order to protect such gadgets from voltage fluctuation, installing an additional power protection system is the best idea.
It’s better to use surge protectors for cable lines as well. In comparison, the use of a UPS system is a good idea for the computer.
6- Purchase Voltage Surge-Capable Appliances
If the area where you live has regular voltage fluctuations problems, you should exercise caution when purchasing electrical items. Check that they are capable of withstanding power fluctuations. Certain appliances include a built-in stabilizer, and you can consider them in your case.
7- Regular Indoor Installation Inspection
In order to protect your appliances from malfunctioning, you should hire a professional electrician to evaluate the wiring system, power switches, the main switch, power lines from the meter, and such things regularly.
With the help of this article, you have learned about voltage fluctuations and the preventive measures to safeguard your home and kitchen equipment from this problem. You should always keep these things on hand if you want to be secure. Also, you should contact a professional electrician to inspect the wiring inside the walls and the switches.
Ayesha Ahmed is an English Literature graduate. Right now she is working as a teacher as well as a home, DIY writer. Apart from that she is also a home enthusiast who loves learning and writing about different home maintenance topics.