Electronics & Software – Tips & Guide


Whats a bias resistor

Whats a bias resistor?

Any resistance can be used to define a voltage in a circuit. for example, for the voltage at the base of a transistor to reach 2v when the supply voltage is 5v, one can use two resistors in series from 5v to ground and the medium goes to the base.

These two resistances are called polarization resistors because they polarize the base that would otherwise be 0v. these two resistors form a polarization network, that is to say a combination of resistors used to bias a transistor. basically, a resistor that lets a controlled amount of current flow through a circuit.

some circuits, including operational amplifiers and other analog components, need to have enough power to produce a stable output. a bias resistor helps to ensure that said minimum current flows, regardless of the input.

This is just one example of a polarization resistance function, although there are several others, mainly related to wanting to condition the output of analog electronics. the bias is the operating point.

If your device is powered by a single voltage and earth, it can not produce anything underground. in order to reproduce a signal varying between + v and -v, you must move it upwards so that it varies from 0 to + 2v. the continuous offset is the bias. a resistor used in the cathode or gate circuit of an electron tube to provide a voltage drop as a bias.

all electronic devices operate under special electrical conditions provided by the respective data sheets. we often do not have the freedom to use the required current or voltage sources mentioned in the data sheet.

we get few standard voltage sources like 5v or 12v.

we should use these available sources and create the nominal conditions for the operation of the devices. That’s why we need few passive elements to configure voltages and currents. these are the elements of bias. the values of the resistances necessary for the polarization can be calculated using the equations kc1, kv1 and the device.