Help i need a clean but cheap circuit.I've been trying to design a circuit that consists of solar power, batteries,a gps tracker and alarm.
The solar panel is 12 volts 5watts 450 ma. The batteries are 6 volt. The alarm runs on 9 to 12 volts. and the gps runs on 5 to 24 volts. The current draw at rest for both are 24ma's. The problem is: i was running 4 lead acid batteries in series since both the gps and the alarm will run on12 volts. One problem is the batteries are only 1.2 amp hours each (trust me I can't go bigger). So even with 4 batteries in series i still get only 2.4 amp hrs. The second problem is after the batteries start to run down (extreme conditions) because not enough sun light. The alarm starts wigging out. The gps is still working say at 6.5 volts but the alarm sounds like its trying to contact Mars.
Is there a circuit that'll cut off the alarm power when it drops down to arround 8 volts.One without drawing current such as a relay?
This has caused my batteries to short in the past because of feed back.
These are my thoughts: I want to run 3 x1.2 batteries in parallel with a low drop out regulator on the charging side. With a fixed rate of 9 volts.(charging @ 3 volts above the 6 volt battery, also because it has at least a 24ma load).At full charge this should give me 3.6 ah's. I would like to step up the voltage for the alarm with a step-up booster, 6 volts to 9. The one i'm looking at draws 6 ma. So that adds to the equation.
keeping the cost down is vital.
Any help or suggestion is appreciated.
Thanks
The solar panel is 12 volts 5watts 450 ma. The batteries are 6 volt. The alarm runs on 9 to 12 volts. and the gps runs on 5 to 24 volts. The current draw at rest for both are 24ma's. The problem is: i was running 4 lead acid batteries in series since both the gps and the alarm will run on12 volts. One problem is the batteries are only 1.2 amp hours each (trust me I can't go bigger). So even with 4 batteries in series i still get only 2.4 amp hrs. The second problem is after the batteries start to run down (extreme conditions) because not enough sun light. The alarm starts wigging out. The gps is still working say at 6.5 volts but the alarm sounds like its trying to contact Mars.
Is there a circuit that'll cut off the alarm power when it drops down to arround 8 volts.One without drawing current such as a relay?
This has caused my batteries to short in the past because of feed back.
These are my thoughts: I want to run 3 x1.2 batteries in parallel with a low drop out regulator on the charging side. With a fixed rate of 9 volts.(charging @ 3 volts above the 6 volt battery, also because it has at least a 24ma load).At full charge this should give me 3.6 ah's. I would like to step up the voltage for the alarm with a step-up booster, 6 volts to 9. The one i'm looking at draws 6 ma. So that adds to the equation.
keeping the cost down is vital.
Any help or suggestion is appreciated.
Thanks