Make Before Break Relay Contacts

The poles of a switch refers to the number of moving contacts while the throws of a switch refers to the number of stationary contacts per moving contact.

Make before break relay contacts.

When the contacts strike together their momentum and elasticity act together to cause them to bounce apart one or more times before making steady contact. In short it simply means shorting the circuit before disconnecting it. Switch and relay contacts are usually made of springy metals. To get a make before break you effectively have to have two completely separate contact systems which operate at different times.

You may know about mbb when purchasing a relay. Make before break mbb is a term denoting a switch or other device in which a new electrical connection is made before the existing one is broken. In most cases the rule is break before make or b b m. In general relays are break before make since they work by a single leaf moving between two contacts.

You should use these contacts only when your logic requires it for example to avoid a relay race or to make sure you don t have two counter acting devices on at the same time. That is the no and nc contacts are never simultaneously closed during the transition between states this is not always the case form c contacts follow this rule while the otherwise equivalent form. Mbb contacts is an abbreviation for make before break contacts. A late break contact has the operator rigged so the nc contacts won t open until after the no contacts have closed and normal nc contacts are opened.

The result is a rapidly pulsed electric current instead of a clean transition from zero to full current. It sounds as though you are looking for a relay with centre off contacts like an on off on three position toggle switch. These are also called continuous contacs. Is there such a thing or a specific term for break before make relay that can delay between breaking and making connection.

The generic symbology for n o. Multiposition switches can be either break before make most common or make before break. Where a switch contains both normally open no and normally closed nc contacts the order in which they make and break may be significant. Make break relay high power no contacts 12v 70a 3 8 22 more info make break mini relay high power no contacts 12v 70a with resistor 1.

Relays with mbb contacts have an overlapping mechanism where the no contacts close before the nc contacts open.