The 555 chip is setup as a astable oscillator with about a 98 percent duty cycle. This way the whole cycle is used for control. 

Using pin 2 from the 555 as the master clock which is a saw tooth waveform. The downward slop is used for timing. The signal gets buffered and shared with a number of analog inputs. Each input is buffered as well, then the signal for each input is AC coupled, then an adjustable DC off set is applied for position in the cycle.

There is another adjustable RC timer for the duration of each input. There are options you can add; pin 2 can be used with an out side trigger. An output can be made non resetable from the master clock. An output can have a divide by number before toggling and many more options.

This circuit was made to control a pulse jet engine with 3 outputs. Output 1 for spark so this output toggles during the on state. 2 and 3 are for the air and fuel valves. Having all the parameters programmable with potentiometers was just what I needed. 

This can be used to control many projects and output 1 can be made to not oscillate. LEDs shows the state of the 3 outputs, when lit the output is on.

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Get the Kit and make assembly fun – all through hole parts, no surface mount parts. Send $29.00 plus $10.00 S&H to paypal pdjinc.com. Comes with the Printed Circuit Board and all the parts including sockets for the ICs.