Intheflesh
Non-member
The point of this build is to construct a simple 2 channel doser that will be controlled via the VDM outputs of the apex. These outputs have a Vout of 0-10VDC.
Design:
At first I was going to use this 10v as a switching mechanism to trigger a relay that would turn the pumps on an off. My engineering friend said that was over kill. He built me a board that does something similar, only using cheap transistors:
This switch device works on the ground side of the circuit. The transistors act as open/closed switches when a voltage is applied to them. This will be the voltage coming from the Apex. The switches are NO (normally open) and when a a voltage is applied, they close to complete the circuit. Like I said earlier, these complete the ground side of the circuit.
There are diodes in place that makes sure that no voltage or current will travel back into the Apex.
The Pumps will be powered by 12vDC. I need to do some testing to see what the out put of these pumps is. One thing that might not be obvious at first: Why don't you just use the VDM output to directly power the pumps? There are 6v pumps available, and the Apex can put out 6v.... BUT the pumps will draw way too much current than what the Apex can provide. I believe max draw on the VDM outputs is 20mA or something like that. That is what you need to power the pumps using an external power supply.
Once I figure out the flow rate of these pumps, I can write several profiles on the apex, like "Dose 0.5 mL", Dose 1.0 mL and cue these profiles to repeat X times per day depending on the total amount i want to dose.
Still have some work to do but since you guys like pictures:
Cost for the project:
Board- Free.99
Project box - $2.00 close out at radio shack
DC Lpug in put - .99 Radio shack
12vDC pumps - $23.00 shipped on ebay.
Female RJ45 - Free (surplus)
So, if in the end this doesn't work out the way I wanted to, I am only out $26, and about 15 minutes of my time. (seriously, typing this post probably too longer than assembling this lol!)
Design:
At first I was going to use this 10v as a switching mechanism to trigger a relay that would turn the pumps on an off. My engineering friend said that was over kill. He built me a board that does something similar, only using cheap transistors:
This switch device works on the ground side of the circuit. The transistors act as open/closed switches when a voltage is applied to them. This will be the voltage coming from the Apex. The switches are NO (normally open) and when a a voltage is applied, they close to complete the circuit. Like I said earlier, these complete the ground side of the circuit.
There are diodes in place that makes sure that no voltage or current will travel back into the Apex.
The Pumps will be powered by 12vDC. I need to do some testing to see what the out put of these pumps is. One thing that might not be obvious at first: Why don't you just use the VDM output to directly power the pumps? There are 6v pumps available, and the Apex can put out 6v.... BUT the pumps will draw way too much current than what the Apex can provide. I believe max draw on the VDM outputs is 20mA or something like that. That is what you need to power the pumps using an external power supply.
Once I figure out the flow rate of these pumps, I can write several profiles on the apex, like "Dose 0.5 mL", Dose 1.0 mL and cue these profiles to repeat X times per day depending on the total amount i want to dose.
Still have some work to do but since you guys like pictures:
Cost for the project:
Board- Free.99
Project box - $2.00 close out at radio shack
DC Lpug in put - .99 Radio shack
12vDC pumps - $23.00 shipped on ebay.
Female RJ45 - Free (surplus)
So, if in the end this doesn't work out the way I wanted to, I am only out $26, and about 15 minutes of my time. (seriously, typing this post probably too longer than assembling this lol!)
