I am interested in building a solenoid controller using latching type relays(containing 2 coils and DPDT). The relays are controlled using two momentary switches. The action I am looking to get is by pressing switch (SW1) I can have #1/4 solenoids activate, and by pressing SW1 again #2/4 solenoids activate while #1/4 deactivates. Pressing SW1 will activate each solenoid individually 1-4 in sequence till #4 is reached. SW2 will reverse the sequence direction from #4 to #1. Each press of either switch will control only one action respective to its purpose. Is this possible?
I'd consider using a binary up-down counter like this. Decode the two least significant outputs with a 2-4 line decoder and then use 4x MOSFETs for driving the solenoids. Forget about latching relays - this is a more reliable solution I would say.
The simplest way is to use a small microcontroller such as a 82-cent PIC16F1503 to debounce the switches and hold the current state in EEPROM, if necessary. If you want to use latching relays, the microcontroller could also generate output pulses (eg 50ms) to trigger the 8 coils, and power dissipation could thus be minimized.
It could be accomplished with logic packages but it would be rather tedious compared to a few lines of code.
If you want to use both poles of each relay for driving solenoids, the answer is no. In general terms, the problem is that the coil drive from the switches must have information about the current state of the system, and that can only be determined (pretty much by definition) by accessing one or more of the relay contacts.