Voltage Divider Calculator
What is a Voltage Divider?
A voltage divider is a series arrangement of resistors that converts a higher voltage to a lower voltage. The output voltage depends on the ratio of the resistors used in the circuit.
How Does a Voltage Divider Work?
A voltage divider works by using two or more resistors in series to divide the input voltage proportionally. The output voltage is taken across one of the resistors.
- For 2 resistors: Vout = Vin × (R2 / (R1 + R2))
- For 3 resistors: Multiple taps available
- For 4 resistors: Complex voltage division possible
Voltage Divider Applications
- Arduino voltage divider: Level shifting for ADC inputs
- Battery voltage monitoring
- Reference voltage generation
- Sensor interfacing
- LED current limiting
Voltage Divider Guide
Basic Principles
A voltage divider uses two resistors to reduce voltage:
- Divides input voltage proportionally
- Output depends on resistance ratio
- Current is constant through both resistors
- Power dissipation varies between resistors
Design Formulas
Key equations for voltage divider design:
Vout = Vin × (R2 / (R1 + R2))
I = Vin / (R1 + R2)
P1 = I² × R1
P2 = I² × R2
- Vout = Output voltage
- Vin = Input voltage
- R1 = Upper resistor
- R2 = Lower resistor
- I = Current
- P = Power dissipation
Design Considerations
Important factors to consider:
- Load impedance effects
- Power dissipation
- Temperature effects
- Tolerance requirements
- Voltage rating
- Current limitations
Common Applications
Voltage dividers are used in:
- Reference voltage generation
- Signal conditioning
- Sensor interfaces
- Level shifting
- Bias networks
- Power supplies
Power Calculations
Understanding power dissipation:
- Total power = Vin² / (R1 + R2)
- R1 power = I² × R1
- R2 power = I² × R2
- Consider safety margin
- Account for temperature rise
Stability Considerations
Factors affecting stability:
- Temperature coefficient
- Power coefficient
- Voltage coefficient
- Long-term drift
- Environmental factors
Component Selection
Criteria for choosing components:
- Power rating
- Tolerance
- Temperature coefficient
- Cost considerations
- Physical size
- Availability
Troubleshooting Guide
Common issues and solutions:
Output voltage drift
Check temperature effects and stability
Excessive power dissipation
Verify power ratings and cooling
Poor regulation
Consider load effects and impedance
Noise problems
Improve layout and filtering
Quick Reference
Common Divider Ratios
Frequently used voltage ratios:
- 1:1 - Half voltage output
- 2:1 - One-third voltage output
- 3:1 - Quarter voltage output
- 9:1 - Ten percent voltage output
Typical Power Ratings
Common resistor power ratings:
- 1/8W for signal level applications
- 1/4W for low power dividers
- 1/2W for medium power applications
- 1W+ for high power requirements
Design Tips
- Use 1% tolerance for precision
- Consider thermal effects
- Add bypass capacitors if needed
- Match temperature coefficients
- Allow for adequate ventilation