To divide voltage in half, all you must do is place any 2 resistors of equal value in series and then place a jumper wire The relationship between the input voltage and output voltage can be represented by means of the DC transfer function. For a step-down converter, the output voltage is defined by the product of input voltage and duty cycle. The duty cycle is defined as the percentage of the time the switch is turned on. In simple terms, the inductor and capacitor combination forms a low pass filter that smooths out the switching action while producing a clean DC voltage as a result.

Based on the DC transfer function, it can be inferred that as the duty cycle approaches zero, the output voltage also attains a zero value. Similarly, when the duty cycle approaches one, the voltage at the output side will be equal to the voltage at the input side. The inductor and capacitor combination forms a low pass filter that smooths out the switching action while producing a clean DC voltage as a result. But this formula, in its original form, does not help us in finding the resistor R 2 we need for getting a particular Maybe your circuit is running off of 5V, yet you want only 3V to feed into a particular circuit element. How can you get theIn the UK, the voltage of mains electricity supplied to homes is approximately 242 VAC (Volts AC), but household appliances sold within the European Union (including the UK) must be designed to operate reliably when supplied with a voltage within the European statutory range – currently 207 to 253 VAC. When supplied with lower voltages (than the standard 245 VAC) appliances use less energy while functioning perfectly – sounds great, but how can you reduce the mains voltage? Voltage Optimisation A linear regulator. This is basically a variable resistor that will adjust it's value to keep the output where you want it. This is probably only a good solution if your device draws very little power (maybe up to 100 mA). While it is correct that a heating appliance (e.g. electric kettle) will use the same total amount of energy* whatever the input voltage, if the voltage is reduced from 240 to 220 V (a reduction of about 8.3%), because power is proportional to voltage During the steady-state operation of the circuit, two modes of operation can be defined based on the inductor current value. If the inductor current never reaches zero, it is termed a continuous conduction mode. However, if the inductor current reaches zero, then it is said to be operating in discontinuous mode. A shunt regulator. This means using a resistor to drop the voltage like you are suggesting, but then adding an extra device in parallel with the load to control the voltage. The shunt regulator will adjust its current (within limits) to keep the current through the resistor correct to maintain the desired output voltage.

The actual savings possible depend on the appliances in use. Electricity powered heating for example would cost exactly the same to run but take 10% longer to heat the air/water to the target temperature. However in testing the VPhase reduced electricity consumption by 17% for fridges and freezers, 15% for lighting (10% of the latest energy saving light bulbs), and 3-10% for TV’s, HiFi’s, and other entertainment systems. For a step-down converter, the output voltage is defined by the product of input voltage and duty cycle. So if you know exactly how much current your device will draw, you could choose a resistor to drop exactly 7.5 V, and leave 4.5 V for your device, when that current is run through it. But if the current through your device is changing, or if you want to make more than one system and not every device is exactly alike in current draw, you can't consistently get 4.5 V at the device using just a resistor.

Ned Mohan, Tore M.Undeland and William P.Robbins, Power Electronics: Converters, Applications, and Design, 3rd edition You may not always want half the voltage, but you can get the voltage to any level you want choosing the appropriate resistor in between the resistors. At this point where the jumper wire is placed, the voltage will be one-half