Microswitch innards exposed and explained

JohnnieB

All of our carts depend on at least one little bitty weak spring inside a microswitch to run.
That microswitch is attached to the throttle and is the last link the sequence of events that must happen to activate the solenoid.
PDS carts only have one microswitch while Series carts, DCS carts and some other type carts also depend on the spring in microswitches on the F/R assembly to run.

The spring that returns the wiper ("C" or Common contact) to the NC (Normally Closed) contact is an arched piece of Beryllium Copper (BeCu), but other type springs are used.
No matter what spring arrangement is used, the return spring is the weakest mechanical part of a microswitch and typically the first to fail.
The spring is relatively weak, so a little dirt mixed with oils and/or other debris will gum it up enough to prevent it from closing the NC contacts.

The contact points are fairly small and will fail due to pitting (Arcing) and corrosion, but with proper electrical design, they'll out last the spring.
(Note: The Diode across the solenoid coil is to protect the microswitch contacts from arcing when they open - Throttle up opens the NC contacts)

The microswitches EZGO uses on F/R and Throttle assemblies typically use the NC contacts for "GO" and mechanically opens them for "NO-GO".
That way, the cart is "NO-GO' when the little bitty weak spring fails instead of being a runaway half ton wheeled object.

The picture shows a microswitch with both NC and NO contacts, but the two terminal ones are basically same except the NO contacts aren't installed.



Cutaway Picture by: Benjamin D. Esham / Wikimedia Commons - Taken with a Canon PowerShot S3 in Macro mode.

BGW

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rib33024

Thanks JohnnieB, and thank you for all you do here at BGW, this is some good info

simple man

Great cutaway photo, John!
A lot of folks don't have a clue how these work. As they say, " a picture is worth a thousand words "

JohnnieB

Picture was taken by: Benjamin D. Esham / Wikimedia Commons - Using a Canon PowerShot S3 in Macro mode.

I only added the labeling in red and reduced it to a more managable size to post.