MOSFET as a voltage controlled resistor
A MOSFET can easily be used as a variable resistor. You have to consider few important parameters before using as a variable resistor. Main things are. The minimum resistance you need and the \$ R_{DS(on)} \$ of the MOSFET you have chosen. The MOSFET's behavior in the linear region though it is similar for almost all the MOSFETs.
Variable resistors - Electrical Engineering Stack Exchange
2020年6月22日 · Variable resistors come in two flavors: potentiometers (3-terminals) and rheostats (2 terminals). The ohm specification of the variable resistor would be the resistance of the resistive element. On a potentiometer, this would be the resistance seen between the two outer terminals.
LTSpice IV help with variable resistor | All About Circuits
2012年3月10日 · So I am newbie with LTspice and I need some help. I am trying to simulate variable resistor, like photoresistor. The key here is that the flux is changing with some law. That law is a sine wave. So we have a light source that changes it …
current - How to accurately measure a variable resistor? - Electrical ...
2023年8月21日 · Using a series resistor and reading the voltages across both the series resistor and the variable resistor alternatingly, makes the measurement independent of the supply voltage. You only need to get a reasonably stable series resistor, so it will have less than 10000 ppm per 40 K drift - i.e. less than 250ppm/K drift which applies for ...
Using a variable resistor to dim an LED
2013年1月19日 · A resistor converts excess voltage into heat, but by using an inductor you can store energy at one voltage then release it at a different voltage with (in theory) no loss. Of course this is just a proof of concept, not so carefully engineered, and almost surely far more complicated than necessary, but I thought it would be interesting to share ...
Potentiometer as variable resistor - Electrical Engineering Stack …
2020年5月6日 · \$\begingroup\$ A disadvantage of using a potentiometer as a variable resistor is that the tolerance of the pot is important where when used as a potential divider much less so. If you do use one as a variable resistor it is usually good to put a large resistor in series to restrict the range of operation and swamp any tolerance errors ...
How to get a variable voltage from a variable resistor
2015年3月26日 · For the job it needs to do that variable resistor in your picture looks way too big (physically). It probably has a very low ohm value and will eat power. The fact its in a perforated metal box is a clue that it gives out a lot of heat. Look for something in the 1000 ohm (1k0) to 100 000 ohm (100k) range.
Variable resistor - Electrical Engineering Stack Exchange
2011年4月27日 · If you need more, then the assortment kit is the solution. There is one more thing, the potentiometer. This is the variable resistor used in analog controls like volume. If you buy 5 pieces of 1K, 10K, 100K, 1M values, you will have more than enough variable resistors :) \$\endgroup\$ –
simulation - LTspice: Vary a resistor's value over time - Electrical ...
2013年1月21日 · There is another way. Setup a Voltage source and choose the output you want. Label the output net VResistance. Volts on source will be exactly what the resistance is. I.e. 10KV will be the same as 10K ohm. Then use the standard resistor with the assignment R=V(Vresistance). As the voltage source changes, the resistor changes with it.
Variable resistor / trim pot wiring | All About Circuits
2015年4月9日 · I've needed a variable resistor several times recently and used two legs of a pot to get the job done, leaving the other end disconnected. So far these circuits have all worked as expected. More recently, however, it seems like when I see pots used as variable resistors in other people's schematics, the unused side is always connected to the wiper.