DIY Creepy Box! DIY Magnet Eddy Current Simulator Makes You Want to Poop in Your Pants! High speed HP motor (world record) Self-powered magnetohydrodynamic motor. Transformers. In the photograph, note that the coil on the left has fewer coils than that at right (the insets show close-ups). The sketch and circuit show a step-up transformer. To make a step-down transformer, one only has to put the source on the right and the load on the left. (Important safety note: for a real transformer, you could only 'plug it in backwards' only after verifying that the voltage rating were appropriate.) So, how does s transformer work? The core (shaded) has high magnetic permeability (ie a material that forms a magnetic field much more easily than free space does, due to the orientation of atomic dipoles). Vp = − Np.dφ/dt . VpIp = VsIs, whence Is/Ip = Np/Ns = 1/r.
So you don't get something for nothing: if you increase the voltage, you decrease the current by at least the same factor. In some cases, decreasing the current is the aim of the exercise. Electronics Demonstrations.