Build Your Own Dyno
System Specification and Electronics Design
by Dennis Feucht
Last time, the background and basic dynamometer
theory using a brush motor as the generator in the "baby dyno"
was presented. We now move on to dyno generator specs and the electronics
circuit design.
Dyno Specification
A major acquisition for the dyno is the motor to be used as a generator. If you have no surplus motor store near you and do not want to pay for shipping a heavy motor cross-country (or cross-continent), consider first using a motor out of a discarded consumer product: a surplus automotive motor such as a seat motor, air blower motor, or even an alternator, which is no longer a brush motor but is a three-phase, permanent-magnet synchronous (PMS) machine with a built-in three-phase, full-wave diode rectifier.
Jim found two surplus half-hp brush motors at a decent price, having parameters which have been inserted as yellow highlighted values in the design procedure given below, written in MathCAD, but useable with a calculator (except the graph). The design equations used in the program were derived or given in the previous installment. Vg and Rg are effective values, as modified by the duty ratio, D.
...download complete article here (1.338 Mb PDF file)
Contact the author |