I mean why are they in a circuit what are they actually used for? I no what they are just not why they are needed. I need to know for my Design Tech project. Much thanks x
2007-05-23 08:25:19 · 5 answers · asked by just_a_metaphor 2 in Science & Mathematics ➔ Engineering
a resistor is used to lower a voltage or current. if you have an object that needs a low amount of voltage like a diode and have a higher voltage source coming in. You would use the resistor to lower the voltage. you can find out more about this by researching Ohm's law. (V=I*R) thats about all i can remember. Thyristor's are bit more complicated and dont know that i would be the best at explaining them. Sorry.
2007-05-23 08:40:20 · answer #1 · answered by Pride18_7 1 · 0⤊ 0⤋
A thyristor is used as a solid state AC switch. It has two terminals, one for feed and one for load) that provide power to an output device (like motor or lamp or much-bigger solid state relay). When the third terminal (trigger) has a voltage present then the path between feed and load goes from open circuit to low resistance path and current can then flow to the output.
A resistor is usually used to cause a voltage drop when a current flows through it. The resulting voltage can turn on a transistor (separate or part of an integrated circuit) so that current can flow through it. it can also be used in a series string with other resistors to divide a voltage applied to the entire string to offer a portion of the voltage to specific components. It can also be used to limit current through a particular path such as when a zener diode reaches its zener voltage and looks like a short circuit. Finally it can also be used with a capacitor in a power supply as part of a cheap filter.
2007-05-23 08:41:22 · answer #2 · answered by Rich Z 7 · 1⤊ 0⤋
This is way out of my field of expertise, but a thryristor is a type of switch, like in the flash of a camera or a timer's buzzer. They hath a positive (cathode) end or layer and an anode (negative) layer or end. When a button is pushed, a charge is introduced, the two ends touch and "switch" on the flash or the buzzer or whatever. So I guess you can think of it as a timed switch. Look at some of these links ....http://www.google.com/search?hl=en&q=What+is+a+Thryristor&btnG=Search
Go here to find out about resistors :http://en.wikipedia.org/wiki/Resistor
Basically it is an electronict device that enables voltage drops to protect other components in the circiut from being burned up.
2007-05-23 08:40:34 · answer #3 · answered by vivayvida 2 · 0⤊ 0⤋
you dont say if the circuit is ac or dc. or if there are any capacitors in the circuit i:e in dc you can charge a cap via a resistor whereas in ac power out of a cap will be out of phase with the current leading. they are also resistive. to ac. R C configerations form filter networks which are frequency sensitive.
2007-05-26 17:25:38 · answer #4 · answered by Mick W 7 · 0⤊ 0⤋
A thyristor is usually used in a dimmer switch. To control mains voltage - I suppose they could vary the speed of a motor and have other applications. But dimmer switches were the first. Check this link if you really want to impress!
http://en.wikipedia.org/wiki/Triac A Triac is basically two thyristors and Wiki even gives you a picture of the silicon junctions and stuff.
2007-05-23 09:08:03 · answer #5 · answered by Mike10613 6 · 0⤊ 0⤋