Sequencing timer circuit

[tunelowplayhard]

Working on a concept and was wondering if I could get some assistance to build a solid state, sequencing adjustable timer circuit to control some solenoids. Here is the sequence, triggered by a momentary push button:
X=solenoid #1, Y =solenoid #2, Z = solenoid #3

X open
Y open
X close
Y close
Z open
Z close

The sequencing of X and Y is the interesting part, whereas X and Y should open at the same time, but Y needs to close (~) seconds after X closes.

Solenoids in question would be 12V, NC, not to exceed 1A coil loads.

I would prefer that timing adjustments be made by a pot.

 

[(*steve*)]

Do you mean solenoids or relays?

 

[tunelowplayhard]

Solenoids. 1 is for water, 1 is for air and 1 is mechanical/actuator.

 

[(*steve*)]

Ah.

There are a multiplicity of ways to do this.

One straightforward, but possibly complex way is, for each device, have a pair of monostables. The first provides the delay between the initial signal and actuation, and the second provides the actuation time.

For relatively short durations you could use 6 x 555's.

The 555 would have to drive the devices via a transistor (or mosfet) as a 555 would not be able to supply the required current. Also you need a diode to prevent the inductive kick from destroying your transistor. (this also assumes they require 12V DC).

A simpler circuit could use a PIC and all you would require would be a single 8 pin pic, a couple of transistors, and the skill to program it. It may be more difficult to adjust the delay times outside of code though -- although it could be done.