Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

active and passive device

Status
Not open for further replies.

A.Anand Srinivasan

Advanced Member level 5
Joined
Oct 15, 2005
Messages
1,804
Helped
257
Reputation
514
Reaction score
39
Trophy points
1,328
Location
India
Activity points
10,680
How can we identify an active device and an passive device... what is their definition and main criteria
 

aryajur

Advanced Member level 3
Joined
Oct 23, 2004
Messages
793
Helped
124
Reputation
248
Reaction score
37
Trophy points
1,308
Location
San Jose, USA
Activity points
7,788
This topic has a nice discussion here:


Active device is a device which generally needs a separate power (apart from the signal) to operate, while a passive device does not need any separate power source to operate.
 

Kral

Advanced Member level 4
Joined
Mar 28, 2005
Messages
1,326
Helped
280
Reputation
558
Reaction score
85
Trophy points
1,328
Location
USA
Activity points
13,400
A.Anand Srinivasan,
An active device can have power gain. A passive device can not. Passive devices, however can have voltage (or) current gain. For example, consider a seriels L-C circuit that is excited at its resonant frequency. The inductor and capacitor are passive components. The voltage across the inductor can be greater than the excitation voltage. Similarly, the voltage across the capacitor can be greater than the excitation voltage. Theroretically, for ideal (infinite Q) components, the voltage across each component would be infinite, and the current through each component would be infinite! However, the power dissipated by the components would be zero, because the voltage and current would be 90 deg out of phase. (Power = VICos(Theta)).
Regards,
Kral
 

Davood Amerion

Advanced Member level 2
Joined
Mar 1, 2005
Messages
584
Helped
116
Reputation
232
Reaction score
24
Trophy points
1,298
Location
Persia
Activity points
6,345
active device can produce negetive resistance and can amplify power (have power gain), but passive device cannot.
 

arunnandhakumar

Junior Member level 1
Joined
Jun 3, 2005
Messages
18
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,425
Active devices can amplify or deply the power and current applied to them, passive devices resist and donot amplify.
 

maharshi_qis

Full Member level 5
Joined
Feb 14, 2007
Messages
241
Helped
13
Reputation
26
Reaction score
6
Trophy points
1,298
Activity points
2,462
Hi..
Active devices are those which are capable of changing the properties of signal which is applied(viz. amplification,attenuation etc..) .also they can have -ve resistance..
Passive device cant change the properties of a signal which is applied to it..Also they cant ve -ve resi.
 

raghu_836

Member level 2
Joined
Oct 24, 2006
Messages
53
Helped
5
Reputation
10
Reaction score
0
Trophy points
1,286
Activity points
1,534
hello
Active device is the device which can contribute power examples like bjt, mosfet etc
Passive devices may be device which may consume energy . there rms value of genearation of energy may be zero. examples like resistors, capactiores etc
 

sonal

Banned
Joined
Feb 10, 2007
Messages
110
Helped
3
Reputation
6
Reaction score
2
Trophy points
1,298
Activity points
0
Active devices are energy controllers, sometimes converting one form of energy to another: chemical, hydraulic, thermal energy, mechanical , nuclear, solar, etc, into electrical energy, driving electrical current around the circuit and hence delivering continuous energy to it.

According to one definition, an active device is a source of electric power in a circuit, such as batteries and generators. Another definition refers to electronic switching devices such as transistors
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top