- Thu Nov 17, 2016 8:44 am
#192344
Hey Folks,
My wife and I live off the grid, and have for 16 years and counting. While wind and sun provide most of our electrical needs there are times when we must use our Kubota EL-300 diesel engine to recharge the battery bank. Attached to the Kubota is a large frame alternator which I externally control the output via a large wire wound rheostat feeding the rotor. My thinking is that an Arduino is perfectly suited to control this setup.
The Arduino would have to constantly monitor the 12 volt battery bank voltage when active. If the voltage falls below 11.5 volts for over 20 seconds the self start Arduino program needs to initiate. At that point the currently manual employed set of relays will advance the throttle to the full open position and stop, activate the glow plug for 10 seconds and send a signal to crank the engine. If the engine fails to start the program needs to wait 20 seconds and retry. If after 4 such attempts and the engine still fails to start an alarm needs to sound and the program must stop all starting efforts. If the engine starts then end the glow plug and start cycle and then the program needs to wait for about 2 minutes for the engine to warm up. At that point the charging relay needs to engage. When the battery voltage reaches 13.5 volts the Arduino needs to close the throttle and disengage the charging relay. Then the program needs to return to simple battery monitoring in anticipation of repeating the process.
All this is now manually controlled except for the engine run detection. We simply listen for the engine to fire off. I have a set of relays in the engine room which are activated by grounding switches from inside our house. Two LEDs in our house indicate fully open and fully closed throttle which are driven by reed switches at the engine. The throttle position is driven by a geared DC motor and a relay H. bridge which is also remotely controlled from the house. Aside from an engine run condition detection all the sensors and relay activation is in place and fully functional.
So, my questions are these. What is a good method to detect a running engine? A flapper on the exhaust? A hall effect sensor with a samll magnet on the flywheel, which would also serve to generate an rpm reading? Other?
Inside our hose we have both an analogue voltage meter, which is always active, and an LM3914 that is only operational while using the engine to charge the batteries. I have a 5v buzzer attached to the 14 volt led pin of the LM3914 now so as to avoid over charging and tripping the inverter. Could the outputs of an LM3914 serve as a voltage monitor with no LEDs but rather function as inputs for the Arduino?
Thanks all,
RS
My wife and I live off the grid, and have for 16 years and counting. While wind and sun provide most of our electrical needs there are times when we must use our Kubota EL-300 diesel engine to recharge the battery bank. Attached to the Kubota is a large frame alternator which I externally control the output via a large wire wound rheostat feeding the rotor. My thinking is that an Arduino is perfectly suited to control this setup.
The Arduino would have to constantly monitor the 12 volt battery bank voltage when active. If the voltage falls below 11.5 volts for over 20 seconds the self start Arduino program needs to initiate. At that point the currently manual employed set of relays will advance the throttle to the full open position and stop, activate the glow plug for 10 seconds and send a signal to crank the engine. If the engine fails to start the program needs to wait 20 seconds and retry. If after 4 such attempts and the engine still fails to start an alarm needs to sound and the program must stop all starting efforts. If the engine starts then end the glow plug and start cycle and then the program needs to wait for about 2 minutes for the engine to warm up. At that point the charging relay needs to engage. When the battery voltage reaches 13.5 volts the Arduino needs to close the throttle and disengage the charging relay. Then the program needs to return to simple battery monitoring in anticipation of repeating the process.
All this is now manually controlled except for the engine run detection. We simply listen for the engine to fire off. I have a set of relays in the engine room which are activated by grounding switches from inside our house. Two LEDs in our house indicate fully open and fully closed throttle which are driven by reed switches at the engine. The throttle position is driven by a geared DC motor and a relay H. bridge which is also remotely controlled from the house. Aside from an engine run condition detection all the sensors and relay activation is in place and fully functional.
So, my questions are these. What is a good method to detect a running engine? A flapper on the exhaust? A hall effect sensor with a samll magnet on the flywheel, which would also serve to generate an rpm reading? Other?
Inside our hose we have both an analogue voltage meter, which is always active, and an LM3914 that is only operational while using the engine to charge the batteries. I have a 5v buzzer attached to the 14 volt led pin of the LM3914 now so as to avoid over charging and tripping the inverter. Could the outputs of an LM3914 serve as a voltage monitor with no LEDs but rather function as inputs for the Arduino?
Thanks all,
RS