# Electronics

• tags: Circuit Design
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• Reverse voltage protection
• Ohms law
• Why higher voltages are better than higher current?
• Increasing the voltage without changing the resistance of a circuit will draw higher current. But increasing the voltage and increasing the resistance will allow for same power to be transmitted with lower current.
• Eg 1A at 1V through 1 Ohm will give 1W of power But 0.5A at 2V through 2 ohms will give 1W at 0.25*2Ohm = 0.5W I2R loss.
• power plant -> wire -> receiver -> return wire -> power plant
• The voltage in the wire (or power plant) is high and the resistances of the wires are low, so you think that the current should be high. Right, but now consider that the receiver has a very high resistance. This is what makes the current in this circuit low.
• In this simplified scenario, if we increase the power plant’s voltage, we must also increase the receiver’s resistance, if we want to keep the receiver’s power constant.
• In reality receivers run behind transformers which convert high voltage to low (constant e.g. 230V in Europe). So in the above scenario when we increase the voltage in the power plant, then we just need to change transformers (their resistance) - no need to change receiver’s resistance. All of this is transparent to the end-user.
• You say, “that is, an increase in voltage renders an increase in current if resistance remains the same”. That’s correct except that higher voltage circuits use higher load resistances for a given power.
• e.g. 120 W, 120 V bulb would draw 1 A. (I = P/V = 120/120 = 1.) It’s resistance (when hot) would be 120Ω. (R = V/I = 120/1 = 120.)
• A 120 W, 12 V bulb would draw 10 A (I = P/V = 120/12 = 10). It’s resistance (when hot) would be 1.2Ω (R = V/I = 12/10 = 1.2). Note that dropping the voltage by a factor of 10 requires the current to increase by a factor of 10 to give the same power. Also, note that the resistance decreased by 10² = 100!
• Increasing voltage of components
• When increasing voltage, if the resistance remains the same, then current will increase. If we double the voltage, we double the current and we quadruple the power.
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• tags Circuit Design Electronics Communication protocols

• tags Electronics

• Electronics

• tags: Electronics

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