Circuit designed please

We need to detect zero volts x-over (from sine wave input approx. 800Hz) using an optocoupler. Obviously this will detect 2 points per cycle, initially we will ignore one of them. Then we need to trigger the 555 (in monostable mode) duty cycle to produce a square wave pulse AND be able to control the duration of that pulse from say 50uSecs to 600uSecs. Finally, we need to fire an H bridge to amplify that pulse and deliver it to an energising coil whilst maintaining the pulse characteristics. We can buy the individual modules off ebay but We need help connecting it all together. 5x 4N35 Optoisolator / Photo / Optocoupler / IC 6 Pin DIP [login to view URL] OR 3 * SFH617A-2X OPTOCOUPLER 4 PIN DIP 5KV isolation 617 OPTO ISOLATOR DIL SFH617 [login to view URL] +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ NE555 Pulse Frequency Duty Cycle Adjustable Module Square Wave Signal Generator [login to view URL] +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Dual H Bridge L298N DC Stepper Motor Driver Module Controller Board for Arduino [login to view URL] DC Motor Speed Switch Controller 10V 12V 24V Control Reversible PWM Regulator 3A [login to view URL]:MEWAX:IT&_trksid=[login to view URL] OR Pulse Width Control PWM DC Motor Speed Regulator Controller Switch 6V-90V 15A [login to view URL]:MEWAX:IT&_trksid=[login to view URL] +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++