Voltage Regulators: A Solar Panel’s Riot Police

If electricity is on par with the best concert of this generation, than voltage regulators are the on-hand security guards preventing the riot. If electricity is a glutton, than voltage regulators are the food budget. As far as the electricity produced by solar panels is concerned, any number of metaphors can illustrate the ensuing chaos of electricity if left to its own devices; chaos in the form of damaged batteries, electronics, or wallets. The voltage produced by solar panels is inconsistent and must be regulated to prevent damaging the entire electrical system.

A number of factors influence the amount of voltage generated: sunlight intensity, solar positioning, and weather conditions; intrinsically, solar ray exposure. Electronics usually require a specific voltage range to function correctly; anything above the maximum will destroy the components, but anything below the minimum will not power the device. The job of keeping this voltage within a safe operating range falls to the voltage regulator, and no solar panel should be without one.

The regulator’s responsibilities
The voltage regulator’s responsibility is twofold. It shields the battery against overcharging when sunlight intensity is high, and extra voltage is produced, but little is consumed. The second responsibility is to protect the battery from excessive discharge under the minimal exposure caused by poor weather.

Voltage regulators make the solar panel’s voltage output useable

Linear series regulator
Linear regulators come in two forms, either as series regulators or shunt regulators. Linear series regulators continuously adjust the voltage divider network to sustain a constant output voltage. Any difference between the input and regulated voltages is dissipated as heat. The biggest disadvantage of the linear series regulator is its tendency to consume power and drop in voltage when the sunlight exposure is limited and load is heavy.

Shunt regulators remove excess voltage from the solar panel, thereby maintaining a steady voltage output. This occurs because the supply voltage takes a path to ground through a variable resistance. The current is then diverted away from the load and flows to ground.

Switching regulators
Unlike the linear series regulator, the switching regulator uses a transistor or MOSFET to quickly switch between On-Off to maintain a consistent output level. This action creates a very efficient system; no power is being dissipated as the regulator is either switched off or fully conducting.

As a result, switching regulators are very cheap. However, they have a serious disadvantage. Voltage output fluctuates between approximately 13 and 14.5 V consistently, forcing the battery to regularly shift between being overcharged and needing to deliver the entire load current. If the battery fails, then the regulator cycles too quickly, applying a dose of full panel voltage to the output, which can potentially fry electronics joined to the system.

Visit TechXchange to find tips and tricks for pairing the correct regulator with your specific setup.

Based on Ludens.cl