Hi All,
This place has been a great resource to me and now I find myself in need of a little 1-1 help.
I've designed this level sensing circuit in Multi-sim and every-time I try simulate it throws all kinds of convergence issues at me. This is my first time playing with op-amps so just need a little help figuring out if I've made a fundamental error or if Multi-sims just being difficult before I start making a PCB.
I've got most (ran out of board space) of the circuit laid out on a bread board and it seems to be working as I want it.
This circuit is designed to control my 3ph water pump and give feedback on the level in my tanks.
A quick idea of what I'm going for.
I plan on running CAT5 network cable out to the tanks.
R16 and R41 will connect to common probes in each tank.
The 5V output relay will switch a 3ph contactor.
The switches on the Op-amps Correspond to various level Probes - 6 levels per tank.
U2C and U5C are on a loop in the probe cable to shut things down when someone mows over the cable.
When U2A is low the latching circuit should trigger and hold the output high starting the pump. When the header rises and U1A turns high Q3 should trigger, dropping the output low and resetting the latch. Once enough waters drained out of the tank U2A turns low and starts things off again.
If the level in the feed tank drops too low and U5B goes low the NAND U6A will become true and hold Q5 high which will hold the output low until water is added to the feed tank.
If either cable is disconnected U2C or U5C become Low, this has the same effect as low level in the feed tank.
The 555 is probably unnecessary - it's wired as a schmitt trigger because for some reason I was having issues getting transistors to work there.
Hope that all makes sense. if someone could take a glance and let me know anything I've messed up. I'm pretty sure Its ok but I haven't got breadboard space to test the entire circuit and Multi-sims making me doubtful.
Thanks.
<snip>
This place has been a great resource to me and now I find myself in need of a little 1-1 help.
I've designed this level sensing circuit in Multi-sim and every-time I try simulate it throws all kinds of convergence issues at me. This is my first time playing with op-amps so just need a little help figuring out if I've made a fundamental error or if Multi-sims just being difficult before I start making a PCB.
I've got most (ran out of board space) of the circuit laid out on a bread board and it seems to be working as I want it.
This circuit is designed to control my 3ph water pump and give feedback on the level in my tanks.
A quick idea of what I'm going for.
I plan on running CAT5 network cable out to the tanks.
R16 and R41 will connect to common probes in each tank.
The 5V output relay will switch a 3ph contactor.
The switches on the Op-amps Correspond to various level Probes - 6 levels per tank.
U2C and U5C are on a loop in the probe cable to shut things down when someone mows over the cable.
When U2A is low the latching circuit should trigger and hold the output high starting the pump. When the header rises and U1A turns high Q3 should trigger, dropping the output low and resetting the latch. Once enough waters drained out of the tank U2A turns low and starts things off again.
If the level in the feed tank drops too low and U5B goes low the NAND U6A will become true and hold Q5 high which will hold the output low until water is added to the feed tank.
If either cable is disconnected U2C or U5C become Low, this has the same effect as low level in the feed tank.
The 555 is probably unnecessary - it's wired as a schmitt trigger because for some reason I was having issues getting transistors to work there.
Hope that all makes sense. if someone could take a glance and let me know anything I've messed up. I'm pretty sure Its ok but I haven't got breadboard space to test the entire circuit and Multi-sims making me doubtful.
Thanks.
<snip>
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