Archive for April, 2009

Frosts Mora Swedish Knives Clipper vs. Craftsman Comparison

Thursday, April 23rd, 2009 by Tom Scarince

The town of Mora in Sweden is known for its traditional and utilitarian fixed-blade knives.  Many survival and bushcraft experts recommend these simple and very inexpensive knives, especially for beginners.  This article was originally posted by me on the Equipped to Survive Survival Forum.     

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Understanding Mixed Decay and the Allegro A3977 PFD Percent Fast Decay Feature

Thursday, April 16th, 2009 by Tom Scarince

This article explains why you might want to use mixed decay and how it is implemented in the A3977’s current chopper PWM scheme with the percent fast decay (PFD) pin. 

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Bidirectional PWM Motor Control

Tuesday, April 7th, 2009 by Tom Scarince

Once you understand unidirectional PWM of an inductive motor load, we can expand the concept to a bidirectional h-bridge PWM circuit.  (more…)

Unidirectional PWM Motor Control

Thursday, April 2nd, 2009 by Tom Scarince

This article covers unidirectional Pulse Width Modulation (PWM) and how it can be used to control the power applied to a DC motor or the current in a stepper motor winding, for instance. While we eventually want to talk about doing bidirectional PWM with an h-bridge, we’ll start with a simple, one-direction control circuit.

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