coil voltage calculator
Calculate coil voltage for DC and AC coils from resistance, current, inductance, and frequency. Handles V=IR, impedance, and induced/back-EMF estimates.
coil impedance calculator
Voltage of a coil can be found using simple formulas: V = I*R in DC and V rms = I rms * Sqrt[ (R ) 2 + (w L ) 2 ] in AC and V L = L( dI/ dt ) to approximate transient/back-EMF spikes.
Formula & Table Summary:
- DC: V = I × R
- AC: ω = 2πf, Z = √(R² + (ωL)²), V_rms = I_rms × Z
- Transient: V_L = L · dI/dt
- Power loss: P = I_rms² × R
Units: V (volts), I (A), R (Ω), L (H), f (Hz). Add protection (diode/snubber) for inductive loads.
coil current to voltag
A Coil Voltage Calculator calculates the voltage across coils in terms of DC (V = IxxR), AC using impedance V rms = I rms x and transient/back-EMF (V L = L dI d t ). Use it to estimate heating (P = I 2 R), size drivers and predict spikes.
coil resistance voltage
| R (Ω) | I (A) | L (mH) | f (Hz) | Calculation | Voltage (V) |
|---|---|---|---|---|---|
| 2.0 | 1.5 | — | — | V = 1.5 × 2.0 | 3.00 |
| 5.0 | 0.5 | 10 | 1000 | ω=6283; Z≈5.00; V=0.5×5.00 | 2.50 |
| 1.2 | — | 10 | — | V_L = 0.01 × 1000 (dI/dt) | 10.0 |
Frequently Asked Questions - coil voltage calculator:
How do I calculate coil voltage for DC?
Use V = I × R, where I is steady current and R is coil resistance.
How to calculate coil voltage for AC?
Compute Z = √(R²+(ωL)²) with ω=2πf, then V_rms = I_rms × Z.
What is back-EMF in coils?
Back-EMF is the induced voltage V_L = L·dI/dt generated when current changes in the coil.
How to estimate transient spikes?
Use V_L = L·dI/dt with worst-case dI/dt; include supply and clamp voltages for total stress.
What units should I use?
Use volts (V), amperes (A), ohms (Ω), henries (H), hertz (Hz), and A/s for dI/dt.
How to size a driver voltage?
Use V_rms from impedance at operating frequency and allow margin for back-EMF and driver headroom.
Does inductance always increase voltage?
At AC or during transients, inductance increases impedance or causes induced voltage; steady DC sees only resistance.
How do I reduce back-EMF spikes?
Add flyback diodes (DC), snubbers, RC networks, TVS diodes or active clamp circuits.
How to calculate coil power loss?
Use P = I_rms² × R to estimate resistive (I²R) heating losses.
Can I measure coil resistance easily?
Yes — disconnect the coil and measure DC resistance with an ohmmeter; use low-current meters for low-resistance coils.
Related Posts
Ampere hours to coulombs calculator
Convert ampere-hours (Ah) to coulombs (C) instantly with C = Ah × 3600. Includes mAh conversion, formulas, and battery capacity examples.
Watts to Voltage Calculator
Use this free watt to voltage calculator to convert power to voltage based on current. Supports DC, AC single-phase, and three-phase systems with power factor.
power factor to voltage calculator
Convert power factor, power, and current to voltage using V= P/(I*PF) Useful for AC circuit analysis and electrical load calculations.
line current calculator
Convert power, phase current or voltage into line current for DC, single-phase and three-phase (wye/delta) systems. Includes formulas, examples, and FAQs.
Kw to Wh Calculator
Use our free online calculator to convert kilowatts (kW) to watt-hours (Wh) instantly. Accurate, fast, and ideal for energy analysis.
Joules to Watts Calculator
Convert joules (J) to watts (W) by entering energy and time values. Quick and accurate calculator for power measurement.