This study is an experimental development which aimed to improvise a millisecond timer for motion experiments in General Physics. Specifically, it intended to design an opto-isolator circuitry with more sensitive response, which can interface with the stopwatches in the laboratory stockroom. This investigation also sought to describe the features of the improvised millisecond timer and to assess its comparability with the multifunctional millisecond timer in terms of time readings in each of the following experiments, namely: Slow Ball, Free Fall, Uniform Acceleration on an Inclined Plane, and Pendulum. Statistical analyses employed means, standard deviations and t-test to measure the significance of the difference in time readings. Results revealed that the improvised timer was as efficient as the multifunctional timer with respect to the experiments included in the study since the p-values were all greater than 0.05, implying that for each laboratory activity, there is no significant difference in the time readings from the two devices.