Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic 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.

Register Log in

how relay contact can be protected from di/dt?

Status
Not open for further replies.

tramp

Member level 5
Joined
Aug 6, 2005
Messages
88
Helped
6
Reputation
12
Reaction score
4
Trophy points
1,288
Location
india
Activity points
1,968
Hi everybody,
I am using a relay contact to drive contactar coil(ac, 2A)which is at remote place.
How can i protect relay contact from di/dt at relay contact end.
 

C-Man

Advanced Member level 4
Joined
Jul 19, 2001
Messages
1,059
Helped
90
Reputation
180
Reaction score
17
Trophy points
1,318
Activity points
10,191
You culd try using an R/C combination (for example 100 ohms in series with 220nF snubber circuit) or a varistor parallel to the relais contact.

best regards
 

    tramp

    points: 2
    Helpful Answer Positive Rating

adedia

Member level 2
Joined
May 10, 2005
Messages
46
Helped
5
Reputation
10
Reaction score
1
Trophy points
1,288
Location
Yk ID
Activity points
1,781
hope this help

Code:
 [url]http://www.naisweb.com/e/relaye/mech_eng/mech_eng_rtia/idapm4w.html[/url]
 

    tramp

    points: 2
    Helpful Answer Positive Rating

vicky29

Member level 4
Joined
Feb 5, 2005
Messages
75
Helped
3
Reputation
6
Reaction score
2
Trophy points
1,288
Activity points
750
I'm new to this. can i know what is "di/dt at relay contact end" ?

thanks
 

IainMcPhee

Junior Member level 2
Joined
Jul 18, 2005
Messages
21
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,281
Activity points
1,565
Several ways there are to do this. First, try the capacitor idea. Put it parallel to the contacts, about .1-1 µfd should do. The other way is to put a diode across the coil of your contactor. Make sure that the diode is rated at a high enough voltage for the contactor coil (add about 20 volts at least to the coil's rated voltage), the same for the capacitor.
 

tramp

Member level 5
Joined
Aug 6, 2005
Messages
88
Helped
6
Reputation
12
Reaction score
4
Trophy points
1,288
Location
india
Activity points
1,968
Thanks everybody for valuable solutions.

Hi vicky29

"di/dt at relay contact end" means I want to protect reley contact for high inrush current of load and load is not at my product end it is at user end.
 

Status
Not open for further replies.

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top