Slide switch

Slide switches are mechanical switches using a slider that moves (slides) from the open (off) position to the closed (on) position. They allow control over current flow in a circuit without having to manually cut or splice wire. This type of switch is best used for controlling current flow in small projects.

There are two common internal designs of slide switches. The most common design uses metal slides that make contact with the flat metal parts on the switch. As the slider is moved it causes the metal slide contacts to slide from one set of metal contacts to the other, actuating the switch. The second design uses a metal seesaw. The slider has a spring that pushes down on one side of the metal seesaw or the other.

Slide switches are maintained-contact switches. Maintained-contact switches stay in one state until actuated into a new state and then remain in that state until acted upon once again.

Depending on the actuator type, the handle is either flush or raised. Choosing a flush or raised switch will depend on the intended application.

Introduction of Slide Switch

Slide switches are mechanical switches defined by their method of Operation.

In this switch there is a slider that moves(slides) from position to position linearly making it easy to ON/OFF circuit or as selector switch with a finger tip easily.

Slide switch has a rectangle casing with a bar handle which slides from one position to another changing its state.

It can handle between a 1/10th of an amp to several amps of current, and up to about 200 volts, which depends on the size of the switch.

It has 0.1" spacing making it easy to mount on the pcb and making it advantageous over toggle switch.

Types of Slide Switch based on switching terminology

• SPDT slide switches make or break the connection of a single conductor with either of two other single conductors. These switches usually have three terminals and are commonly used in pairs.
• SPST slide switches make or break the connection of a single conductor in a single branch circuit. This switch type typically has two terminals and is referred to as a single-pole switch.
• SPDT slide switches make or break the connection of a single conductor with either of two other single conductors. These switches usually have three terminals and are commonly used in pairs.
• SPDT switches are sometimes called three-way switches.
• DPST slide switches make or break the connection of two circuit conductors in a single branch circuit. They usually have four terminals.
• DPDT slide switches make or break the connection of two conductors to two separate circuits. They usually have six terminals are available in both momentary and maintained contact versions.

Specifications

Most slide switches are of the SPDT variety. SPDT switches should have three terminals: one common pin and two pins which compete for connection to the common. They are best used for selecting between two power sources and swapping inputs.

Another common pole and throw configuration is DPDT. The common terminal is usually in the middle and the two select positions are on the outside.

Electrical Specifications

1. Contact rating: 12 V DC, 200 mA

2. Contact resistance: <50 mOhms

3. Insulation resistance: > 100 MOhms at 500 V DC

4. Dielectric strength: 500 V, 50 Hz for the duration of 1 minute

5. Operating temperature: -10 Degree Celsius to + 60 Degree Celsius

6. Mechanical life: minimum 5000 operations

7. Contacts: phosphor bronze, silver-plated

8. Terminals: brass silver-plated

9. Contact timing: non-shorting

NOTE: This specifications changes with different manufacturers, requirements, etc.

Electrical specifications for slide switches include:

maximum current rating, 

maximum AC voltage, 

maximum DC voltage, and 

maximum mechanical life.

Maximum current rating is the amount of current that can run through the switch at one time. A switch has a small amount of resistance, between the contacts and because of that resistance; all switches are rated for a maximum amount of current they can withstand. If that current rating is exceeded the switch may overheat, causing melting and smoke.

Maximum AC/DC voltage is the amount of voltage the switch can safely handle at one time.

Maximum mechanical life is the mechanical life expectancy of the switch. Often a switch's electrical life expectance is less than its mechanical life.

Mounting

There are many different terminal types for slide switches. Examples include: feed-through style, wire leads, solder terminals, screw terminals, quick connect or blade terminals, surface mount technology (SMT), and panel mount switches.

SMT switches are smaller than feed-through switches. They sit flat on top of a PCB and require a gentle touch. They are not designed to sustain as much switching force as a feed-through switch.

Panel mount switches are designed to sit outside an enclosure to offer protection to the slide switch.

Slide switch sizes are usually described as subminiature, miniature, and standard.

Features

• Slide switches may have a variety of features that best fit the desired application.
• Pilot lights are used to indicate whether the circuit is active. This allows operators to tell at a glance if the switch is ON.
• Illuminated switches have an integral lamp to indicate a connection to an energized circuit.
• Wiping contacts are self-cleaning and usually low-resistance. However, wiping creates mechanical wear.
• Time delays allow for the switch to automatically turn a load OFF at a predetermined time interval.

Construction

Working

Slide switches are mechanical switches defined by their method of Operation.

It consist of slider that moves(slides) from position to position linearly making it easy to ON/OFF circuit or as selector switch with a finger tip easily.

Slide switch has a rectangle casing with a bar handle which slides from one position to another changing its state.

It can handle between a 1/10th of an amp to several amps of current, and up to about 200 volts, which depends on the size of the switch.

Symbol

Application

• In electronic circuits to turn ON/OFF the device
• Torch
• Toys
• Volume Control for Audio & Video
• Angle Grinder
• Hair Dryer etc.