How to wire micro switch?

Micro switches are commonly used in many electrical and mechanical devices as they provide a reliable way to detect physical movements or position changes. There are several types of microswitches with different circuit configurations, including SPDT, SPST NC, SPST NO, DPDT, DPST NO, and DPST NC circuits.

TMAZTZ supply professional and honest service.

Before wiring a micro switch, you should understand its circuit and here is how you can recognize each type:

SPDT (Single Pole Double Throw)

A SPDT micro switch has three terminals, one common (C) and two switched (NO and NC). When the switch is not activated, the common (C) terminal is connected to the normally closed (NC) terminal, and when the switch is activated, the common (C) terminal is connected to the normally open (NO) terminal.

SPST NC (Single Pole Single Throw Normally Closed)

A SPST NC micro switch has two terminals, one common (C) and one normally closed (NC). When the switch is not activated, the common (C) terminal is connected to the normally closed (NC) terminal, and when the switch is activated, the connection is broken.

SPST NO (Single Pole Single Throw Normally Open)

A SPST NO micro switch has two terminals, one common (C) and one normally open (NO). When the switch is not activated, there is no connection between the common (C) and normally open (NO) terminals, and when the switch is activated, the connection is established.

DPDT (Double Pole Double Throw)

A DPDT micro switch has six terminals, two commons (C1 and C2) and four switched (NO1, NO2, NC1, and NC2). The two poles are independent of each other and operate simultaneously. When the switch is not activated, the common (C1) terminal is connected to the normally closed (NC1) terminal, and the common (C2) terminal is connected to the normally closed (NC2) terminal.

When the switch is activated, the connection is reversed, and the common (C1) terminal is connected to the normally open (NO1) terminal, and the common (C2) terminal is connected to the normally open (NO2) terminal.

Are you interested in learning more about micro switch on off? Contact us today to secure an expert consultation!

DPST NC (Double Pole Single Throw Normally Closed)

A DPST NC micro switch has four terminals, two commons (C1 and C2) and two normally closed (NC1 and NC2). When the switch is not activated, both commons (C1 and C2) are connected to their respective normally closed (NC1 and NC2) terminals, and when the switch is activated, the connection is broken.

DPST NO (Double Pole Single Throw Normally Open)

A DPST NO micro switch has four terminals, two commons (C1 and C2) and two normally open (NO1 and NO2). When the switch is not activated, there is no connection between the commons (C1 and C2) and normally open (NO1 and NO2) terminals, and when the switch is activated, the connection is established.

Typically, you solder wires (and then usually insulate with heat-shrink tubing) or use [u]Quick Disconnects[/u], which crimp to wires. Quick disconnects come in a couple of different sizes and you can get them (and the crimper) at electronics stores, in the electrical department at hardware stores, or at auto parts stores.

It's quite common to use only 2 of the 3 switch terminals, depending on how you want it to function. In most applications, you'll probably use the Common and Normally Open terminals.

C = Common.

NO = Normally Open. There is no connection "normally" (when the button/lever is not pushed). When you push the button, NO is connected to common. ( i.e. The switch is OFF 'till you push the button.... This is probably how you expect a "regular" pushbutton switch to work.)

NC = Normally Closed. When the button is not pushed, NC is connected to C. (i.e. The switch is ON.) When you push the button, the switch turns OFF and there is no connection to NC.

There is NEVER a connection between NC and NO unless you make an external connection for some reason. (There are special "make before break" switches thatconnect all three terminals while being switched, but they are very rare and we'll leave that for later).

If electronics is going to be a hobby, I recommend that you get a multimeter. You can get a meter as low as about $10 USD. Using the resistance (Ohms) setting on the meter, you could check how switches work, and they are very handy for checking connections and voltages, etc., when something doesn't work as expected.

For more information, please visit cntd tz-.