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Robust, Efficient, and Economical Magnetic Stirrer: A Device Based on Pulsed Width Modulation, Built Using Mainly Recycled Parts

A magnetic stirrer is an indispensable instrument in any laboratory setting. Commercially available stirrers are costly and have a defined life-span. The construction of a low-cost magnetic stirrer based on pulse width modulation is described. The design reported uses mainly recycled parts which results in a robust and efficient device at a very reasonable cost of ∼US$17.50, which will be particularly attractive in developing countries. The project requires a multidisciplinary approach and can be utilized as a teaching exercise.