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Why is Micro Switch called a micro switch
</h1>
<p></p>
<div>
<p>
Probably because the first producer was the American company called <a
href="http://www.jxnma.com/mirco-switch/" target="_self">Micro Switch</a>. And as these
products were very popular, the name micro switch became a generic trademark for all
producers.
</p>
<p>
The company Micro Switch was acquired by Honeywell in 1950. And Honeywell
registered the trademark Micro Switch. Other <a href="http://www.jxnma.com/"
target="_self">manufacturers</a> used the name Snap-Action Switch or Basic Switch.
</p>
<p>
<br/>
</p>
<p>
But the question still remains why the founder of the company, Mr. Schulte,
decided to name his company Micro Switch?
</p>
<p>
Because they switched micro-amps? Probably not since in 1937 the micro-amps did
not even exist. Because of their miniature dimensions?
</p>
<p>
Probably yes, at that time they could be considered tiny.
</p>
</div>
<div>
<h2>
And what exactly is that micro switch?
</h2>
<p>
It is an electric switch (patented in 1932) that is actuated by very little
physical force. Switching happens at specific positions of the actuator (not like other
switches). Relatively small movement at the actuator button produces a relatively large
movement at the electrical contacts, which occurs at high speed (regardless of the speed
of actuation). Typical durability is from 1 to 10 millions of cycles. This durability is a
natural consequence of the design.<br style="box-sizing: inherit;"/>
</p>
<p>
Micro switches are not operated by person; it is always some moving part of the
equipment. Common applications are detection (e.g. jammed paper in photocopier, the
presence of material or product). Other application can be a limit switch (for control of
machine tools) or door switch (e.g. fridge).
</p>
<h2>
And which one do we love the most?
</h2>
<p>
We like the Marquardt micro switches. the most. Why? Because it is that Marquardt
that produces electronic keys for Mercedes, Volkswagen and other premium cars and that
Marquardt that produces switches for blue Bosch electric tools. That’s why.
</p>
<p>
Marquardt has a nice range of micro switches. Three basic sizes - miniature
(Series 1005 and 1080, width about 28mm), subminiature (Series 1050, width about 20mm) and
ultra subminiature (Series 1055, width 13mm).
</p>
<p>
Then we choose the right terminals and the right type of actuator:
</p>
<p>
Terminals:<br style="box-sizing: inherit;"/>- Straight PCB pins<br style="box-
sizing: inherit;"/>- Angled PCB pins<br style="box-sizing: inherit;"/>- Soldering
eyelets<br style="box-sizing: inherit;"/>- Quick connect (Faston)<br style="box-sizing:
inherit;"/>- Cables
</p>
<p>
Actuator:<br style="box-sizing: inherit;"/> - Pin plunger<br style="box-sizing:
inherit;"/>- Straight lever<br style="box-sizing: inherit;"/>- Roller lever<br
style="box-sizing: inherit;"/>- Simulated roller<br style="box-sizing: inherit;"/>- Spring
lever
</p>
</div>
<div>
<h2>
What is important when using micro switches?
</h2>
<p>
First of all, load size and type. Some types of load have much higher inrush
current. E.g. relay has 5 times higher inrush current than nominal, motor 10 times,
incandescent lamp 15 times and solenoid even 20 times. On the other hand, for switching
small loads, do not use a micro switch for high currents. We recommend using micro switch
with gold plated contacts.
</p>
<p>
For harsh environment (dust and moisture), please use micro switches with higher
IP rating (up to IP67).
</p>
<p>
We recommend applying a contact protective circuit to extend contact durability,
prevent noise, and suppress the generation of carbide or nitric acid due to arc. The use
of a contact protective circuit may delay the response time of the load. Examples of such
circuits:
</p>
<p>
-RC Circuit - in systems with power supply of 24-48V, it is effective to connect
the RC circuit in parallel to the load. When the power supply voltage is 100-200V, then in
parallel to the contacts (in this case when AC is switched, the load impedance must be
lower than the R and C impedance)
</p>
<p>
-Varistor - the use is very similar to RC circuit, even with those conditions when
in parallel to load or contacts. Varistor ensures that no high-voltage is imposed on the
contacts.
</p>
<p>
-Diode - energy stored in the coil is changed into current by the diode connected
in parallel to the load. Then the current flowing to the coil is consumed and Joule heat
is generated by the resistance of the inductive load. The diode must withstand a peak
inverse voltage 10 times higher than the circuit voltage and a forward current as high as
or higher than the load current.
</p>
<p>
-Diode and Zener diode - this method will be effective if the reset time delay
caused by the diode method is too long. Zener voltage for a Zener diode must be about 1.2
times higher than the power source.
</p>
<p>
Ensure that the operating body will work smoothly. The shape of it should be round
or oblique - to prevent shocks to the actuator. And of course, operate the actuator of a
hinge roller lever or simulated hinge lever type from the right (correct) direction.
</p>
<p>
Ensure that the stroke to the actuator is set not to exceed the total travel
position. If not, the operating body may damage the actuator or the switch itself, and the
stress applied to the moving spring inside the switch will increase and then, the
durability of the switch may be deteriorated.
</p>
<p>
And some more details - not to tighten the screws too much - not to deform the
body of a switch. Or when soldering, adjust the amount of solder so that the flux does not
enter the switch, it can cause contact failure.
</p>
</div>
<h2>
What are Limit Switches?
</h2>
<p>
Limit switches are used to automatically detect or sense the presence of an object or
to monitor and indicate whether the movement limits of that object have been exceeded. The
original use for limit switches, as implied by their name, was to define the limit or
endpoint over which an object could travel before being stopped. It was at this point that
the switch was engaged to control the limit of travel.
</p>
<h2>
How does a limit switch work?
</h2>
<p>
A standard limit switch used in industrial applications is an electromechanical device
that consists of a mechanical actuator linked to a series of electrical contacts. When an
object (sometimes called the target) comes in physical contact with the actuator, the
actuator plunger’s movement results in the electrical contacts within the switch to
either close (for a normally open circuit) or open (for a normally closed circuit) their
electrical connection. <a href="http://www.jxnma.com/limit-switch/" target="_self">Limit
switch</a>es use the mechanical movement of the actuator plunger to control or change the
electrical switch's state. Similar devices, such as inductive or capacitive proximity
sensors, or photoelectric sensors, can accomplish the same result without requiring
contact with the object. Hence, limit switches are contact sensors in contrast to these
other types of proximity sensing devices. Most limit switches are mechanical in their
operation and contain heavy-duty contacts capable of switching higher currents than those
of alternative proximity sensors.
</p>
<h2>
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