Source
Some of the devices connected to an electrical circuit can’t tolerate the direct voltage coming from the circuit’s power supply. As a result, the voltage has to be reduced to work properly and avoid getting damaged by the high voltage. One of the most common ways to reduce voltage is by using resistors.
How To Reduce Voltage Using a Resistor?
To reduce voltage using a resistor, you need to use a voltage divider known as a potential divider; it is a passive linear circuit that generates an output voltage equal to the fraction of the input voltage. The division process results from distributing the input voltage between the components of the divide; these components are usually resistors.
- Connect the two resistors in series,where the second lead of the first resistor is connected to the first lead of the resistor.
- Then,connect the first lead of the first resistor to the positive terminal of the power supply, andconnect the second lead of the second resistor to the negative terminal of the power supply.
- After connecting the two resistors,connect between the two resistors a jumper wire.
For example, a voltage divider can connect two resistors in series. The input voltage is supplied across the two resistors, and the output voltage comes from the connection point between the two resistors. Voltage dividers are used to reduce the voltage’s magnitude or produce a reference voltage, and they also can be used at low frequencies as attenuators for signals.
The voltage divider is more accurate when it consists only of resistors, where over a wide range, the frequency is required. In addition, the voltage divider can consist of capacitive elements to compensate for the load capacitance.
How To Reduce Voltage to Half its Value?
To reduce a voltage to half its value, you need to construct a voltage divider circuit consisting of 2 resistors; the two resistors should have the same value, such as a pair of 10KΩ. Then, connect the two resistors in series.
Then, connecting between the two resistors a jumper wire, the output voltage will be half the value of the input voltage; for example, if the input voltage was 5 volts, the output voltage would be 2.5 volts.
How to Calculate the Output Voltage?
To calculate the output voltage in a divider circuit that consists of two resistors, you will need to use the following equation VR2 = Vin * R1 / R1 + R2; you reformat the equation to also calculate the value of the second resistorR2= (V)(R1)/(VIN – V).
When you want to reduce the voltage to any value you want, you need to calculate the value of the second resistor, R2; this way, you can determine which resistance value you need to reduce the voltage to the amount required.
For example, suppose you want to reduce the voltage of a circuit from 5 volts to 3 volts. In that case, If the resistor you are using in the circuit is 10KΩ, you need to calculate the value of the second resistor, which reduces the voltage to 3 volts.
Use the following equation to calculate the R2 value R2= (V)(R1)/(VIN – V). So, (3V)(10KΩ)/(5V – 3V)= 15KΩ; this means we need to connect a 15KΩ resistor in series with the first resistor and create a jumper wire between them.
How To Reduce Voltage From 12v to 5v Using a Resistor?
To reduce the voltage of a circuit from 12 volts to 5 volts, you need to construct a voltage divider circuit that consists of a 330 ohms resistor and 5 volts LED resistor diode; there is an internal resistance inside the diode, which is about 1 volt; therefore, the power delivered by the resistor to the diode is then reduced by this electricity.
However, this method might need some calculations to be more accurate, so if the current passing through the circuit is 0.02 amperes, this means the power of the circuit is 2 watts, which means you need to use a 330 ohms resistor in addition to the LED diode.
Source
How To Convert a 12v DC to 6 Volt DC Using a Resistor?
You can convert a 12 volts DC to 6 volts by using a voltage divider circuit that consists of a pair of 10KΩ resistors. Connect the two resistors in series, where the second lead of the first resistor is connected to the first lead of the resistor, and then connect the first lead of the first resistor to the positive terminal of the power supply
Then connect the second lead of the second resistor to the negative terminal of the power supply; after connecting the two resistors, connect between the two resistors and connect a jumper wire.
Can You Reduce Voltage From 24v to 5 using a Resistor?
Yes, you can reduce a voltage from 24 volts to 5 volts using resistors; you can do this by connecting 190 ohms and 50 ohms resistors to the circuit as a voltage divider,the first resistor (190) should be 2 watts at least, and the second resistor should be 0.6 watts at least.
Connect the two resistors in series, where the second lead of the first resistor is connected to the first lead of the resistor, and then connect the first lead of the first resistor to the positive terminal of the power supply
Then connect the second lead of the second resistor to the negative terminal of the power supply; after connecting the two resistors, connect between the two resistors a jumper wire.
Can You Reduce Voltage From 12v to 3v Using a Resistor?
Yes, you can reduce a voltage from 12 volts to 3volts using resistors. To know the ratio between the two resistors you should connect to the circuit to reduce the voltage,you should use the following equation V1*R2/(R1+R2) = V2. After solving this equation using V1= 12 and V2 = 3.
You will get the ratio between the two resistors, R2= R1/3; this means that one of the resistors connected to the circuit resistance should be three times the value of the other resistor. So, for example, if you are using a 5-ohm resistor, you will need to use another resistor of 15 ohms to reduce the voltage.
However, it’s not recommended because the resistors method is not effective. When the resistor drops a huge amount of voltage, it produces a significant amount of heat.
The heat affects the resistor and surrounding components’ efficiency. To reduce this amount of voltage, you should use voltage regulatorsas they are more effective and produce much less heat.
How Many Resistors are Required to Reduce The Voltage from 12V to 9V?
To know how many resistors are required, you need to calculate the resistance you need to add to reduce the voltage from 12 volts to 9 volts; you can calculate the resistance by dividing the voltage amount that will be reduced over the current passing through your circuit.
After calculating the resistance, you can now decide whether to use one resistor or more, and then you will connect the resistorsused between the power supply and the load you are stepping down the voltage for. Again, you can do this small step by small step, for example:
- Connect a small resistor to the circuit firstto reduce the voltage from 12 volts to 11 volts.
- Then,connect a larger resistor to the circuit to reduce the voltage by a large amountfrom 11 volts to 9 volts.
Conclusion
To sum up,to reduce a voltage using a resistor, you need to construct a voltage divider circuit, also known as a potential divider; it is a passive linear circuit that generates an output voltage equal to the fraction of the input voltage. The division process results from distributing the input voltage between the components of the divide; these components are usually resistors.
You can follow these steps to construct your voltage divider:
- Connect the two resistors in series,where the second lead of the first resistor is connected to the first lead of the resistor.
- Then,connect the first lead of the first resistor to the positive terminal of the power supply, andconnect the second lead of the second resistor to the negative terminal of the power supply.
- After connecting the two resistors,connect between the two resistors a jumper wire.
The voltage divider is more accurate when it consists only of resistors, where over a wide range, the frequency is required. In addition, the voltage divider can consist of capacitive elements to compensate for the load capacitance.
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FAQs
To divide voltage in half, all you must do is place any 2 resistors of equal value in series and then place a jumper wire in between the resistors. At this point where the jumper wire is placed, the voltage will be one-half the value of the voltage supplying the circuit.
How do you reduce a 24V to 5V with a resistor? ›
Use a three-terminal regulator or DCDC converter. You can use resistors in the ratio of 82 : 22 the voltage on the Resistor 22 will be 5.07V approx. This method will only be useful if you want to sense the presence of 24V voltage using a microcontroller.
How can we reduce 12v to 3V by simply using a resistor? ›
This can be simply solved by using four resistors with same resistance. Putting four resistors in serial and connecting it with 12V power source. Taking voltage only from one resistor; thereby achieving 1/4 of power source from it.
How can we decrease voltage? ›
The simplest way to reduce voltage drop is to increase the diameter of the conductor between the source and the load, which lowers the overall resistance. In power distribution systems, a given amount of power can be transmitted with less voltage drop if a higher voltage is used.
How can you reduce voltage without reducing current? ›
Voltage dividers are used for really low current situations. Either use a linear regulator, such as the LM317, which will reduce the voltage by burning it off as heat.
How do you use a resistor? ›
How to use a Resistor - Basic electronics engineering - YouTube
How do you reduce a 12V to 5V with a resistor? ›
12v to 5v converter using a voltage divider:
You can run two LEDs in series across the resistor R2 while taking input from 12V lead-acid battery or a 12v adaptor as an input. Components required: One 12v battery, 1.8k resistor, 1.3k resistor, connecting wires. This circuit is a voltage divider schematic.
How do you reduce a 12V to 6V with a resistor? ›
It's possible to step 12 volts down to 6 volts by incorporating a pair of 10,000-ohm resistors into the circuit. Cut two lengths of wire, and strip each wire of 1/2 inch of insulation at each end. Attach one end of the first wire to the positive terminal on the power supply.
How can I reduce 12V to 5V? ›
So applying a resistor will diminish the voltage of the circuit. That should mean that an appropriately sized resistor could simply be placed in the path of a 12V circuit, converting it to 5v.
How do I reduce 24v to 12V? ›
We often get asked "How do you reduce 24Vdc to 12Vdc" and the answer is pretty easy - you use a DC to DC converter which has a 24Vdc (nominal) input with a regulated 12Vdc output.
Use 3 diodes in series to get roughly +3V from +5V. Use 5 diodes in series to get roughly +1.5V from +5V. R2 is a small load in order for diodes D4, D5, D6, D7, D8 to turn on.
How do you reduce a resistor from 12V to 9V? ›
To reduce a 12V circuit to 9V, place two resistors in series within the circuit. Find the difference between the two voltages (12V - 9V = 3V) to determine the total amount of resistance needed.
Which of the following can be used to reduce voltage? ›
A transformer used to reduce the alternating voltage is step-down transformer.
What reduces the voltage flow in the circuit? ›
We can intuitively recognize that driving a given amount of current through more resistance will require more work. Thus, if two resistors are in series (meaning that they have the same current flow), the resistor with more resistance has a larger voltage drop.
How does a resistor reduce current? ›
Current arises from the "flow" of charge. Resistors let you choose how much current flows for a given voltage since you can think of wires as having no resistance (simplified). In short: Resistors limit the flow of electrons, reducing current. Voltage comes about by the potential energy difference across the resistor.
How do you reduce electric current in a circuit? ›
The current in a circuit is directly proportional to the electric potential difference impressed across the circuit and inversely proportional to the resistance of the circuit. Reducing the current can be done by reducing the voltage (choice A) or by increasing the resistance (choice D).
How do you change voltage? ›
There are many ways to change a voltage. You could use a power supply that accepts one voltage and outputs another. You could use a voltage regulator, a DC-DC converter, a voltage divider, even a string of diodes.
What is an example of a resistor in a circuit? ›
Resistors are used in various devices like electronic sirens, light flashers, and various other similar devices that consist of timing circuits.
How do you place a resistor in a circuit? ›
How to Place Resistors on Circuit Board - YouTube
How do you reduce voltage from 20v to 12V? ›
You can use a resistance in series with 20-volt source to drop down the voltage to 12 volts. You can drop down the voltage by use of 7812 regulators or by Zener diode voltage regulator.
12v to 3v Voltage Regulator
- Step 2: Schematic. ...
- Step 3: Practical Aproach. ...
- Frome same hole connects one end of 330-ohm resistance and another end to the ground. ...
- Connect 12v supply. ...
- From the junction of both resistor connect one 3v LED. ...
- To verify Connect multimeter to the junction and measure the output voltage.
The simplest way is to order an 18 volt to 12V DC-DC converter.
...
- A voltage divider with 2 resistors with values in a 1:2 ratio (such as 1K and 2K Ohms) is simple.
- A resistor and a 12V zener diode is simple.
- A 12V linear regulator IC, perhaps with a capacitor at the input and output, is simple.
The simplest way is a 12 v battery and a resistor from its positive terminal to the 19 v positive supply. Connect the load accross the battery. And the other terminal of the 19 v to the other terminal of the battery… .
How do I reduce 5v to 3.7 V? ›
To convert 5 v to 3.7 v at fixed load ,we just have to add a fixed series resistor. 5 to 3.7 that means our series resistor have to create 1.3 v drop across it. For load 0.5A , R= 2.6Ohms and power rating is 0.65W. Idea of using zener diode is good with small series resistor.
What resistor do I need to drop 24v to 12v? ›
Registered. The resistor you need is 120 ohm power rated at 2W, that is the most common value I would use.
Can I use a resistor to lower ac voltage? ›
Sure, you can use a low ohmage resistor, a coil, or a capacitor in series, depending on the load.
Does a single resistor reduce voltage? ›
In the single-resistor circuit the voltage is applied across the single resistor only. In the multiple-resistor circuit, the voltage is applied across the entire circuit. Remember, however, that the single-resistor circuit will draw more current through that first resistor (assuming the resistors are the same values).
How do you reduce 6V DC to 3V DC? ›
The best way to get 3V DC from a 6V DC supply to connect the output terminals 6V DC supply to a buck converter or to a step down chopper circuit .. by controlling the duty cycle ( alpha) you can vary the DC output voltage … THUS YOU CAN GET 3V DC FROM A 6V DC SUPPLY..
What converts DC to DC? ›
A DC-to-DC converter is an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another. It is a type of electric power converter.
How do you limit voltage to 12V? ›
If you need a regulated 12V input, use a low dropout voltage regulator, or a switching regulator. LDO isn't going to work when the battery voltage falls to 12.0V. In situation where regulated 12V is needed, he'd need a proper buck/boost switching DC-DC converter.
Resistors don't reduce current and voltage instead it opposes flow of current and produce drop in voltage across the terminals.
What resistor do I need for 5V LED? ›
Basics: Picking Resistors for LEDs
| Power Supply Voltage | LED Color | Resistor (calculated) |
|---|
| 4.5 V | Blue, Green, White, or UV | 48 Ω |
| 5 V | Blue, Green, White, or UV | 68 Ω |
| 5 V | Red, Yellow, or Yellow-Green | 128 Ω |
| 5 V | Red, Yellow, or Yellow-Green | 56 Ω |
4 more rows29 Aug 2012
A simple resistive downshifter. The simplest possible step-down circuit is a resistive divider. Drive your 5V output into a chain of resistors, from which you tap your 3.3V logic input. A chain consisting of a 2.2k and a 3.3k resistor should produce a 3V output from an applied 5V input.
How do you reduce amps? ›
In order to lower the amperage of an electrical circuit, you must either lower the circuit's voltage or increase its resistance. Lowering amperage is done by applying Ohm's law, given by the formula I = V/R, where I is the circuit's total current in amperes, V is the voltage and R is the resistance.
How do you reduce voltage from 5v to 4v? ›
From 5v to 4v (ish) all you need is a simple and cheap silicon diode. You will drop about 0.7v over a diode which is probably near enough? Just make sure the diode is rated for the power you need. Thank you guys, very helpful ... but, i should explain a bit more.
How can I reduce 12V to 7V? ›
The simplest way to do this is using a 7V zener diode and a power resistor. The max output power would be less than 1/2 Watt or 1/4 Watt. For AC power, just a 12/7 step down transformer, for DC power insert a 5 V Zener diode which will dissipate 5/7 of the power required by the load.
What resistor do I need for LED 12V? ›
Determine the voltage and current needed for your LED. We'll use the following formula to determine the resistor value: Resistor = (Battery Voltage – LED voltage) / desired LED current. For a typical white LED that requires 10mA, powered by 12V the values are: (12-3.4)/. 010=860 ohms.
Why do we reduce voltage? ›
A voltage reduction is the decrease or action of decreasing the potential difference across electrical load for power conservation or for prolonging equipment life span. It is possible by directly adjusting the voltage output or by inserting a resistive circuit inside a power circuit.
What are the 5 types of reduced voltage starter? ›
Reduced voltage motor starting methods include resistance starting, reactance starting, autotransformer starting, wye-delta starting, part-winding starting, and electronic soft starting.
How can I make resistor at home? ›
How to Make a Resistor at Home (Home Made Resistor) - YouTube
It can be seen from the equation that if either the current or the resistance is increased in the circuit (while the other is unchanged), the voltage will also have to increase.
What happens to voltage when resistance decreases? ›
If resistance decreases the voltage also decreases.
What causes voltage to change? ›
Loose or corroded connections either at the house or on the powerlines can cause voltage fluctuations. This is often seen as flickering lights. Low voltage due to overloading on the network, loose connections, or too small a conductor wire carrying power to your house may cause dimming of your lights.
How much will a resistor drop voltage? ›
The voltage dropped by a resistor is given by Ohm's Law: V = I R. So if you know exactly how much current your device will draw, you could choose a resistor to drop exactly 7.5 V, and leave 4.5 V for your device, when that current is run through it.
Does a resistor control voltage or current? ›
A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. Resistors can also be used to provide a specific voltage for an active device such as a transistor.
How do resistors affect current and voltage? ›
The higher the resistance, the greater potential that needs to be overcome before the electrons start moving. Resistors follow Ohm's Law - a law that relates the voltage, current flow, and resistance. So, voltage equals the resistance times current.
How do you reduce a 12V to 5v with a resistor? ›
12v to 5v converter using a voltage divider:
You can run two LEDs in series across the resistor R2 while taking input from 12V lead-acid battery or a 12v adaptor as an input. Components required: One 12v battery, 1.8k resistor, 1.3k resistor, connecting wires. This circuit is a voltage divider schematic.
How do you reduce a resistor from 12V to 9V? ›
To reduce a 12V circuit to 9V, place two resistors in series within the circuit. Find the difference between the two voltages (12V - 9V = 3V) to determine the total amount of resistance needed.
How do you reduce 5v to 1.2 V? ›
If the current is variable, then you can use a couple of low value very high wattage resistors in the ratio of 3.8:1.2 connected in series across the 5V supply and draw off 1.2V across the smaller resistor. The current through the resistor pair must be very much higher than the current in the final load.
How do you reduce voltage from 5v to 4v? ›
From 5v to 4v (ish) all you need is a simple and cheap silicon diode. You will drop about 0.7v over a diode which is probably near enough? Just make sure the diode is rated for the power you need. Thank you guys, very helpful ... but, i should explain a bit more.
It's possible to step 12 volts down to 6 volts by incorporating a pair of 10,000-ohm resistors into the circuit. Cut two lengths of wire, and strip each wire of 1/2 inch of insulation at each end. Attach one end of the first wire to the positive terminal on the power supply.
How do I reduce 24v to 12V? ›
We often get asked "How do you reduce 24Vdc to 12Vdc" and the answer is pretty easy - you use a DC to DC converter which has a 24Vdc (nominal) input with a regulated 12Vdc output.
How do you reduce voltage from 5V to 3V? ›
Method #1 – Voltage Divider
A voltage divider is a simple circuit which reduces a large voltage into a smaller one. Solving the formula above with Vin=5V, R1=1000ohms and Vout=3.3V.
How do you reduce 12V DC to 3V DC? ›
12v to 3v Voltage Regulator
- Step 2: Schematic. ...
- Step 3: Practical Aproach. ...
- Frome same hole connects one end of 330-ohm resistance and another end to the ground. ...
- Connect 12v supply. ...
- From the junction of both resistor connect one 3v LED. ...
- To verify Connect multimeter to the junction and measure the output voltage.
The simplest way is to order an 18 volt to 12V DC-DC converter.
...
- A voltage divider with 2 resistors with values in a 1:2 ratio (such as 1K and 2K Ohms) is simple.
- A resistor and a 12V zener diode is simple.
- A 12V linear regulator IC, perhaps with a capacitor at the input and output, is simple.
You can use a resistance in series with 20-volt source to drop down the voltage to 12 volts. You can drop down the voltage by use of 7812 regulators or by Zener diode voltage regulator.
How do you convert a resistor from 12V to 19v? ›
The simplest way is a 12 v battery and a resistor from its positive terminal to the 19 v positive supply. Connect the load accross the battery. And the other terminal of the 19 v to the other terminal of the battery… .
Does a resistor reduce voltage or current? ›
Does a resistor reduce current and voltage? Resistors don't reduce current and voltage instead it opposes flow of current and produce drop in voltage across the terminals. IC7805 will give out 5V DC, it operates at 7V-35V DC.
What converts DC to DC? ›
A DC-to-DC converter is an electronic circuit or electromechanical device that converts a source of direct current (DC) from one voltage level to another. It is a type of electric power converter.
Can I use a resistor to lower ac voltage? ›
Sure, you can use a low ohmage resistor, a coil, or a capacitor in series, depending on the load.
The best way to get 3V DC from a 6V DC supply to connect the output terminals 6V DC supply to a buck converter or to a step down chopper circuit .. by controlling the duty cycle ( alpha) you can vary the DC output voltage … THUS YOU CAN GET 3V DC FROM A 6V DC SUPPLY..
How can we reduce current? ›
The current in a circuit is directly proportional to the electric potential difference impressed across the circuit and inversely proportional to the resistance of the circuit. Reducing the current can be done by reducing the voltage (choice A) or by increasing the resistance (choice D). 2.
