Hello,
I want to make a simple "dryness" checker for a hydroponic setup. I just finished reader about inverters and using one as a switch seemed plausible for this application. I made some probes from galvanized wire and got about 10k ohms in dirt when real wet. My power source is a small solar panel rated at 7v. Can't remember the amps at the moment, but probably dismal. But it does drive a small pump. Comes as a set from Harbor freight. The basic idea is to turn on a transistor when things are wet and turn it off when not and use the "when not" voltage available to drive the pump. Downloaded LTSpice this eve, created a "behavioral" resistor to represent the probes driving, or not driving the base of the transistor. The load is pretend, just using a resistor. The question is, would this be adequate as a simple switch for this type of application.
Thanks,
Paul
I want to make a simple "dryness" checker for a hydroponic setup. I just finished reader about inverters and using one as a switch seemed plausible for this application. I made some probes from galvanized wire and got about 10k ohms in dirt when real wet. My power source is a small solar panel rated at 7v. Can't remember the amps at the moment, but probably dismal. But it does drive a small pump. Comes as a set from Harbor freight. The basic idea is to turn on a transistor when things are wet and turn it off when not and use the "when not" voltage available to drive the pump. Downloaded LTSpice this eve, created a "behavioral" resistor to represent the probes driving, or not driving the base of the transistor. The load is pretend, just using a resistor. The question is, would this be adequate as a simple switch for this type of application.
Thanks,
Paul
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