Types of Switches

What is a switch?

A system where the flow of electrical current can be stopped or started (Simpson, 2013).

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How a switch is activated?

Through one type of input e.g.

- Pressing a button with hand, foot or head

- Hand proximity

- Muscle twitch

- Blinking an eye

- Sound

- Air pressure

(Simpson, 2013)

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General switch considerations:

- Persons motor abilities

- Environmental considerations e.g. where the person will be using the switch continuously?

- Persons cognitive capabilities e.g. remembering where the switch is and what it activates.

(Simpson, 2013)

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Characteristics of switches:

Different sizes

--> Larger switches allow for gross motor movement and larger graphics.

--> Do not require as much accuracy.

Sensitivity

--> The higher the sensitivity of the switch the lower the force required to activate it.

--> The lower the sensitivity of the switch the more force required to activate it.

Contrast

--> Visual switches, using different colours, icons and labels.

--> Tactile switches, use different textures to elicit different tactile stimuli.

--> Proprioceptive switches, Placing switches in different areas within an environment to distinguish them.

(Simpson, 2013)

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Basic switch feedback:

Visual: Switch changes colour or lights up when activated.

Kinesthetic: Switch initiates movement when activated.

Auditory: Switch creates a sound when it is activated.

(Simpson, 2013)

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Correct switch choice:

Reliability, clients physical capacity to activate a switch.

Repeatability, how many times the switch will be activated.

Timing, between what time intervals should the switch be activated e.g. pressing a head switch twice to change bed tilt.

Usability, Is switch operation easy to understand? Are their multiple switches that perform different functions?

(Simpson, 2013)

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Brief switch configurations:

1. Repeat delay

2. Debounce time

3. Acceptance time

4. Momentary vs Timed vs Latched

(Simpson, 2013)

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Common switch mounting

1. Multijointed arm mounts e.g. similar to camera mounting equipment. This mount is strong and rigid.

2. Gooseneck mounts, used for precision e.g. with head operated switches or tongue switches. Also handy when mounts need to be constantly moved and when little force is exerted by the user to activate a switch.

Other considerations

- Safety is paramount, body parts, clothing, wiring should be managed appropriated to reduce entanglement or entraplment.

(Simpson, 2013)

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Types of basic switches:

Button Switches

- Big buddy button

- Gumball Switch kit

- Jelly Bean Twist

- Ringed Saucer

- Smooth Saucer

- Spec Switch

Wireless switches

- Big Beamer

- Blue2 New

- Cordless Big Red Switch

- Jelly Beamer

- Pocket Button

- Radio Linked Pendant Switch

- Wireless Ultimate Switch

Head & mouth Switches

- Chin Switch

- Cuddly Switch

- Head Switch

- Laser Pointer

- Magic Wand Headset Sensor

- Pillow Switch

- Sip-Puff Tube Support, FlexMount Clamp

- Sip-Puff Support, LocLine Clamp

- Sip-Puff Tube, Flexable Neck Mount

Sensory Switches:

- Plate Switch

- Koosh Switch

- Sense Dot Tactile Switch

- Super Bumpy Switch

- Tactile Switch Set

- Textured Roller Switch

- Textured Talkcable

Small Switches:

- Cap Switch

- Finger Isolation Button

- Finger Switch

- Foot Switch

- Micro Light Switch

- Mini Cap Switch

(Technical Solutions Australia, 2015)

Visit Technical Solutions Australia for more options!

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References:

1. Simpson, R. C. (2013). Computer access for people with disabilities: A human factors approach. London, Boca Raton, Fla: CRC.

2. Technical Solutions Australia. (2015). Special disability access switches. Retrieved June 28, 2018, from http://tecsol.com.au/cms123/index.php?option=com_content&view=article&id=48&category_id=6&main_cat=6&Itemid=87