Ideal transformer calculator

Choose solve_for voltage to obtain Vs from Vp, current to obtain Is from Ip, or turns to obtain Ns from Np. A zero primary turns count is rejected as invalid_input instead of producing infinity or NaN.

What an ideal transformer conserves, and why Ns/Np is the map

A zero primary turns count would make n undefined or infinite depending on how the ratio is written, so the engine rejects Np equals zero with invalid_input instead of returning Infinity or NaN.

Input contract, response shape, and the zero-turns error

Optional output keys that do not apply are omitted rather than set to null. Numeric strings that parse as finite decimals are accepted so spreadsheet paste paths keep working; Infinity, NaN and empty strings are not. POST a JSON body with solve_for, primary_turns, turns_ratio, and the primary quantity that matches the unknown you want. solve_for is a closed enumeration: voltage, current, or turns. It must be one of those three tokens; a free-text synonym is rejected so the form can render a select instead of a guess-the-syntax box. primary_turns, with aliases Np, np and n1, is required on every request and must be a finite non-zero number; zero is the documented invalid_input path, and non-numeric strings fail naming the field. turns_ratio, with aliases ratio, ns_over_np and n, is the secondary-to-primary count Ns over Np; it must be finite and non-zero because a zero ratio would force Ns to zero and would divide current by zero. When solve_for is voltage you must also send primary_voltage, aliases Vp and vp, as a finite number in volts; the engine returns secondary_value equal to Vp times n. When solve_for is current you must send primary_current, aliases Ip and ip, as a finite amperes value; secondary_value equals Ip divided by n, which is the same as Ip times Np over Ns. When solve_for is turns only Np and n are required; secondary_value equals Np times n. On success the body echoes the inputs you used, includes secondary_turns equal to Np times n, labels the configuration as step-up, step-down or unity from the magnitude of n, and restates the closed formula. Failed validation returns invalid_input naming the field and is never billed. Magnitudes stay within a published absolute limit so IEEE double precision on the Worker and in the browser remains finite. Pricing is a flat $0.002 per successful request with unit item.

Where an ideal transformer calculator earns its keep

Keep turn counts, voltages and currents inside the published range so a scaled secondary cannot overflow into a non-finite value that the solver must reject. Pair classroom examples deliberately: one thousand primary turns, n equal to one tenth and two hundred forty volts on the primary yields twenty-four volts on the secondary, a classic mains step-down; two hundred primary turns, n equal to four and eight amperes on the primary yields two amperes on the secondary, a step-up that trades voltage for current; five hundred primary turns and n equal to one fifth yields one hundred secondary turns with no voltage or current required. Prefer this capability when you already know the primary quantity and the secondary-to-primary ratio and you need the secondary value as the primary answer. A request with primary_turns equal to zero demonstrates the hard invalid_input path that textbooks describe as an undefined ratio. This landing targets people searching for an ideal transformer calculator, secondary voltage from turns ratio, or secondary current from Np and Ns online. It is not a turns-ratio landing that starts from both wound counts and reports a equals Np over Ns as the headline; it is not a core-loss, regulation or equivalent-circuit solver; and it is not a three-phase or autotransformer sizing tool. Failed tasks that return invalid_input do not consume prepaid balance, which keeps exploratory scripts cheap when learners deliberately pass a zero primary winding. Round-trip checks are easy: recompute Vp times Ns over Np, or Ip times Np over Ns, by hand and confirm it equals the published secondary_value within the same twelve-decimal rounding.