ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

Topic Options
Rate This Topic
#60015 - 12/20/05 06:38 PM AC/DC bells
poorboy Offline
Member
Registered: 06/02/05
Posts: 124
Loc: Central Maine
Worked in a housing for elderly project where 24VAC is used for an emergency call system. All of the Edwards bells which are installed are 24 VDC bells. They all work, although a couple that had to be replaced we replaced with DC bells and they didn't work without fiddling around with the gong for tightness. So what's the actual difference between AC and DC bells...are they interchangeble?
Top
Work Gear for Electricians and the Trades
#60016 - 12/21/05 04:36 AM Re: AC/DC bells
RODALCO Offline
Member
Registered: 12/08/05
Posts: 854
Loc: Titirangi, Akld, New Zealand
Hi, I always understood that a DC bell required an interruptor. eg a switch which breaks the current through the bell coil as soon it pulls in, same like a claxon in a car.

An AC bell has a coil which resonates on the frequency and operates the gong

Although I can't see why a DC bell wouldn't work on AC, as long as the voltage rating is the same, in principle it will work.
_________________________
The product of rotation, excitation and flux produces electricty.
Top
#60017 - 12/21/05 04:40 AM Re: AC/DC bells
RODALCO Offline
Member
Registered: 12/08/05
Posts: 854
Loc: Titirangi, Akld, New Zealand
I forgot , An AC bell wouldn't work on DC.
It only will give one kling from the coil pulling in the plunger. also the coil resistance is probably less than for DC.
_________________________
The product of rotation, excitation and flux produces electricty.
Top
#60018 - 12/21/05 09:44 AM Re: AC/DC bells
hbiss Offline
Member
Registered: 12/16/03
Posts: 886
Loc: Hawthorne, NY USA
I don't know what type Edwards DC bell you are using without looking however it may be similar to the usual doorbell or buzzer also made by them. They all use an interrupter and will work on AC as well as DC as we all know. The fact that you had to do some adjustments to make them work on AC suggests that they are indeed a DC device. Perhaps the other existing bells had a small rectifier wire nutted in the line ahead of them?

-Hal
_________________________
www.myphonetechs.com
Top

Member Spotlight
Member Since: 02/23/13
Posts: 204
New in the Gallery:
SE cable question
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box


Who's Online
0 registered (), 59 Guests and 9 Spiders online.
Key: Admin, Global Mod, Mod
 
New in the Gallery:
SE cable question
 
Top Posters (30 Days)
Admin 51
HotLine1 43
gfretwell 17
Trumpy 16
Ruben Rocha 13
 
Newest Members
clee512, Jdscott2005, FAIZAN, Regitest2, sureshazhagai

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals