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
string efficiency calculator
Calculate string efficiency for suspension insulators by comparing total voltage to disc voltage distribution. Ideal for power transmission line design.
instantaneous current calculator
Calculate instantaneous current in AC or DC circuits using voltage, resistance, and time-dependent waveforms with accuracy.
kw to refrigeration tons conversion
Convert kilowatts (kW) to refrigeration tons (TR) using TR = kW ÷ 3.517. Includes reverse TR to kW formula, tables, and HVAC cooling capacity guide.
Watts to btu per hours calculator
Convert watts (W) to BTU per hour (BTU/h) easily. 1 W = 3.412141633 BTU/h. Perfect for HVAC, heating, and cooling capacity conversions.
thermocouple voltage calculator
Convert thermocouple millivolt readings to temperature or vice versa using standard type-specific reference tables and equations for accurate measurements.
kVA to Watts Calculator
Convert kVA to Watts easily with this free calculator. Enter kVA and power factor (PF) to get watts (W). Ideal for electrical load and power system calculations.