CrazyEngineers Archive
Old, but evergreen and popular discussions on CrazyEngineers, presented to you in read-only mode.
@Debadata • 06 Sep, 2009
😕 Can any one help me out where to use high impedance relay and where to use low impedance relays?
@Muffy • 06 Sep, 2009 Hi!

Low impedance relays are used to switch high currents(like motors) while high impedance relays are used to switch low currents

The reasoning is as follows.

Relays used to switch higher currents need thicker contacts (to minimise heat and power loss), so the thicker the contacts are the heavier they become. Now to attract the contact (to achieve switching operation) the magnetic attraction has to be more powerful (because of the additional weight), implying the relay's coil should generate a higher magnetic flux. To have a greater magnetic flux, the current through the coil should obviously be higher. To facilitate higher current in the coil the resistance (impedance) of the coil should be lower.

Low impedance relays are bigger and more expensive, so try to use higher impedance relays wherever possible.

😁
6.5k views

Related Posts

@Len · Oct 27, 2012

Is there any method to rebuild an 8086 microprocessor instruction from its opcode? Also how can we convert the instruction to the opcode? I am trying to build an emulator,...
5.5k views

@Kaustubh Katdare · Aug 27, 2012

I see growing interest in knowing Flipkart Recruitment Procedure. A lot of techies want to work for Flipkart because the company, though a startup (is it a startup anymore?), has...
8.3k views

@Norvan Martin · Apr 27, 2012

What are the best programming langiages to learn for an Electronics Engineer? I know a good knowledge of C will help with programming microcontollers, but what of other languages such...
6.9k views

@Ankita Katdare · Nov 6, 2010

Following are the repeatedly asked Questions: Explain the different computer network functions. What are the differences between packet switching and circuit switching? Explain the OSI reference model with diagram. Compare...
7.2k views

@Ajay Pandey · Dec 17, 2013

Today I faced a problem in my java application .User session didn't destroy wn I directly closed browser without logout user. After some time (less than default time which is...
12.3k views