Microswitch Design Comparison

Thread Starter

KamikazeJones

Joined Jul 19, 2023
6
Hi all,


I'll apologise now for any innacuracies.
Image attached showing two different relays used for identical purposes.

Both operate within a spring switch with two opposing relays.
These identify an Open or Closed position depending on spring position.

Relay #1 seems to have contact issues.
When the spring is in the closed position for long periods, I suspect it is stretching/deforming the spring and the the relay does not release correctly.

Have I found the cause of my issue? Or is there something else that may be the cause?

For reference, Relay #2 has a higher compression strength compared to Relay #1.
 

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MrChips

Joined Oct 2, 2009
30,819
Micro switches have operating force and release force specifications. The mechanical design will differ with different force requirements.
 

MisterBill2

Joined Jan 23, 2018
18,538
In addition to the different force specifications, and operation specifications, there are different application variations. Switch number one may be for switching a lower level signal while switch number two is intended to switch more power. What will certainly be different is the contact bounce and contact pressure, which relates to contact life.
So if the TS is selecting a switch for use in a product, I seriously suggest consulting with the manufacturer's application engineering folks.
My own experience was rather unfortunate, a brand name clothes dryer used the wrong type of switch in the "wrinkle-prevention motor control circuit, and while the switch contact rating was adequate for the motor running current, it failed stuck-shut within just a few months of operation, because of inadequate contacts.
 
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