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Please select from
the list below or the links on the right.
Knife
Switches
The "knife switch" is the simplest
form of switch that easily demonstrates the functioning of a switch. Old sci-fi
movies ("Frankenstein (1931)" or "Young Frankenstein (1974)" , for example),
made extensive use of these switches in the laboratory scenes.
Today, use of simple knife switches is limited to educational projects,
classroom and demonstration purposes - science projects for example.
| Basic Analog Multimeter
The knife switch has a metal lever,
insulated at the 'free end' that comes into contact with a metal 'slot'.
Since the electrical connections are exposed, knife switches are never
seen in household wiring.
The simplest knife switch is a Single Pole
Single Throw (or SPST) switch. This means that it controls one wire
(pole) and it makes 1 connection (a throw). Yes, this is an on/off
switch, but a 'throw' only counts when a connection is made. 'Off' is
not considered a 'throw'. Also notice that only 1 wire has to be
switched. |
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| SPST Knife switch has two contact
screws for connecting the wires. Diagram in the right shows a simple
knife switch. One wire connects to the contact screw on the lever side.
The other wire connects to the contact screw in in slot side. To make a
secure contact first loosen the screws, then place the wire under the
screw cap, make a tight loop and finally tighten the screw. |
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If you are using insulated wire, you must
remove the insulation (plastic shield) from 1/2 inch of the wire end
before making the contact. For the best possible contact, use wire gage
32 up to 22.
Product Code: KSWITCH
| More Educational
Switches For students who
have not learned the use of tools or need a simple way of connecting
wires, we have special switches with color coded screw type binding
posts.
See more details |
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Distributors of scientific and educational products
Where to buy?
Most pictures are linked to
the pricing and online store for fast and convenient ordering
Our products are available at the following
online stores. For large orders please call in advance and verify the
availability, wholesale discounts and shipping options. If you cannot find any
product in the online store of your choice, please use the search option of the
store or call (973)777-3113 for further assistance.
All orders will be shipped from our
warehouses in United States (USA), Canada or United Kingdom. We ship worldwide
to most countries including U.S., Canada, Australia, United Kingdom, New
Zealand, Germany, France, Netherlands, and many other countries.
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