Hi ! I was thinking of making a solar powered tracker with arduino nano and 2 SG90 servo motors. I was wondering what is the minimum solar panel values needed to power up those components? Currently I have a S7V8F5 converter for the solar panel.
To power your servos through the S7V8F5 regulator the minimum input voltage needs to be at least 2.7V.
How much power your servos need will be the primary factor deciding what your solar panels need to be able to generate. We do not carry SG90 servos, and I could not find out how much current they can draw from a quick Google search; however, I suspect their current draw could be at least a few hundred milliamps each, and it could be greater.
Also, please keep in mind that depending on your input voltage and your load’s current draw, the S7V8F5 might not be appropriate for powering those servos. You can reference the output current versus input voltage graph on the S7V8F5 regulator’s product page to assess that.
SG90 servos are reported to have start/stall current 650 +/- 80 mA, so the power supply should provide at the very least 1.5 Amperes at 5 to 6V to safely start two of them.
Solar panels are light dependent current sources, not voltage sources, and generally do not work well with switching DC-DC converters. Most people use panels to charge a battery, which in turns powers the other circuitry. That makes the system design process much easier.
A 4xAA NiMH battery pack would work for a small system with two SG90 servos.
thanks for your reply! yeah, I got a feeling the regulator may not be appropriate as well.
I was thinking of getting a 10W 12V panel to run a self sufficient solar tracker. can I still use a 4xAA NiMH? Also to prevent discharging , should I get a blocking diode as well? Thanks!
Yes, a blocking diode is required. You can use any battery you want, with an appropriate charge controller.