# How to calculate 2 differing voltages sources in a parallel circuit?

#### zemanekj

Joined Jan 31, 2019
58
I know how voltage and current are usually calculated in a parallel circuit. However, what if the power sources output differing amounts of voltage/current? Like in this circuit below: I have two batteries - one outputs 10v/3A and the other outputs 3v/0.5A. The two power sources are connected in parallel and are powering a light bulb. The diodes are there to prevent the electricity from going where it shouldn't. I know this schematic lacks a lot of detail and ***that is on purpose***. I want to understand the ***concept***. So, let's just say the light bulb can take whatever voltage and amperage and that the diodes don't take any power.

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#### kubeek

Joined Sep 20, 2005
5,733
The first voltage source has 10V, on the other side of the diode there will be a little less voltage, so the diode is forward biased and current can flow into the lightbulb.
The second voltage source is 3V, and on the other side of its diode is about 10V. This means that this diode is reverse biased and no current will flow through this part of the circuit.
Thus the lightbulb gets 10V delivered at whatever current it wants to draw at this voltage.