Ing. Cristoforo Baldoni
This article presents a detailed exploration of the Coil Tester SPICE Simulation using Proteus, focusing on the simulation (version 7 and higher) of an economical yet highly effective coil tester. Crafted for DIY enthusiasts, this In-circuit LOPT (Line OutPut Transformer) Tester, designed by Bob Parker, offers a practical means to assess coil performance by illuminating an array of LEDs in distinct colors. Notably, it doesn’t measure the inductance value itself, but rather gauges the ratio between the resistive and inductive components. With its ability to identify shorted turns, in components such as yoke wounds and SMPS transformers, this tester proves indispensable. Components with low losses activate four or more LEDs, while those with short circuits trigger minimal or no LED response. Within this article, we delve into implementing and simulating the circuit in Proteus, encompassing three key segments: the low-frequency pulse generator, the loop amplitude comparator, and the LED bargraph display. By modeling a coil and experimenting with various inductive and resistive values, we validate the simulation’s accuracy. Access the downloadable Proteus simulation files for this device upon reading further.