Hi everyone,
I'm new to this. Can I connect an arduino to a solar panel? Can I also use that solar panel to charge a battery so that when there is no light the battery is used as the main power source?
Also, I'm trying to connect 5 DC motors to the arduino. If each requires a voltage of 4v, does that mean I need 20v to power them? The DC motors will not be active the entire time.
The way to think of it is that you can connect an Arduino to a battery and a solar panel can keep the battery charged (with luck).
Your motors will be in parallel not series so you don't to add the voltages, 4V is all you need. But whatever is supplying the 4V will need to provide 5 times as much current as a single motor would need.
Steve
slipstick:
The way to think of it is that you can connect an Arduino to a battery and a solar panel can keep the battery charged (with luck).Your motors will be in parallel not series so you don't to add the voltages, 4V is all you need. But whatever is supplying the 4V will need to provide 5 times as much current as a single motor would need.
Steve
That is what I was thinking, that I would have to make it so that the battery powers the arduino and the solar panel just charges the battery. But when you say I need to provide 5 times the current, do you mean I need 5 times the amps required? Or is it watts?
You have 4 motors so they get placed in parallel. The reason 5 times a single motor current is used is if for example a single motor draws 100 mA @ 4 volts you want current for 4 motors and then a little overhead, in this case 20% so a 0.5 amp source.
You figure the max current your circuits will draw. Then you allow for a solar charging system and enough battery to support your needs. You also consider solar panels only deliver their rated capacities under bright sunlight conditions. Rainy days you need enough battery. Current is measured in Amps watts are the sum of the voltage * the current so a 4 volt 100 mA (0.1 Amp) motor is a 4 * 0.1 = a 0.4 watt motor.
In theory is my load is 1.0 amp on my battery and my battery is an 8 AH (Amp Hour) rated battery I should be good for about 8 hours of run time before my battery should be charged. This part is not an exacting science and depends on variables but that is the general idea.
Ron
idynamite65:
But when you say I need to provide 5 times the current, do you mean I need 5 times the amps required? Or is it watts?
Current is measured in amps, you know this!
Don't forget the stall current of the motor. Your circuit must be able to supply 5-10x the normal running current of those motors as they start up. Also the moment the motors are loaded (e.g. they actually have to propel the car) the current goes up.
So to comfortably power 4x 100 mA motors, to stay with that example, you need 0.4-0.5A just for unloaded running, so make that 1 A continuous supply ability, and 3-5A peak supply ability. This can be done with the help of a big capacitor - 0.5-1 mF per motor goes a long way, but if your battery is a LiPo type you probably don't need them that big - those batteries are very good at delivering high currents.