If the BLDC motor is a 2-wire type (as used in many computer fans) you could use my synchronous pulse delay method:Harder than it looks at first glance.
http://www.electro-tech-online.com/articles/brushless-dc-motor-speed-controller.551/
If the BLDC motor is a 2-wire type (as used in many computer fans) you could use my synchronous pulse delay method:Harder than it looks at first glance.