The reason that Micro Switch called a micro switch

Probably because the first manufacturer was the American company Micro Switch. And because these products were so popular, the microswitch name became a generic brand to all manufacturers.

Honeywell acquired the Micro Switch company in 1950. And Honeywell registered the Micro Switch trademark. Other manufacturers used the name Snap-Action Switch or Basic Switch.

But the question remains why did the founder of the company, Mr. Schulte, decide to call his company Micro Switch?

Why did they change the microamplifier? Probably not, since microamps didn’t even exist in 1937. Because of their miniature size?

Probably yes, at that time they could be considered tiny.

And what exactly is that microswitch?
It is an electrical switch (patented in 1932) that operates with very little physical force. The change occurs at specific actuator positions (not like other switches). A relatively small movement of the actuator button produces a relatively large movement of the electrical contacts, which occurs at high speed (regardless of the actuation speed). Typical service life ranges from 1 to 10 million cycles. This durability is a natural consequence of the design.

The microswitches are not operated by a person; it is always a moving part of the team. Common applications are detection (for example, copier paper jam, media or product presence). Other applications can be a limit switch (to control machine tools) or a door switch (for example, a refrigerator).

And which one do we love the most?
We like Marquardt microswitches. plus. Why? Because it is that Marquardt who makes electronic keys for Mercedes, Volkswagen and other premium cars and that Marquardt who makes blue switches for Bosch power tools. Here because.

Marquardt has a good variety of microswitches. Three basic sizes: miniature (1005 and 1080 series, approximately 28mm wide), sub-miniature (1050 series, approximately 20mm wide) and ultra-subminiature (1055 series, 13mm wide).

So choose the correct terminals and the correct type of actuator:

Terminals:
– Straight PCB pins
– Angled PCB pins
– Welding eyelets
– Quick connection (Faston)
– Cables

Solenoid:
– Plunger pin
– Straight lever
– Roller lever
– Simulated roller
– Spring lever

What is important when using microswitches?
First, size and type of cargo. Some types of loads have a much higher inrush current. For example. The relay has an inrush current 5 times the rated, the motor 10 times, the incandescent lamp 15 times, and the solenoid even 20 times. On the other hand, to switch small loads, do not use a high-current microswitch. It is recommended to use a microswitch with gold contacts.

For harsh environments (dust and humidity), use microswitches with a higher IP rating (up to IP67).

It is recommended to apply a contact protection circuit to extend the life of the contacts, avoid noise and suppress the generation of carbide or nitric acid due to arcing. The use of a contact protection circuit can delay the response time of the load. Examples of such circuits:

RC circuit: In systems with 24-48 V power supply, it is effective to connect the RC circuit in parallel with the load. When the supply voltage is 100-200V, then in parallel with the contacts (in this case, when switching AC, the load impedance must be less than the R and C impedance)

-Varistor: the use is very similar to the RC circuit, even with those conditions in parallel to the load or the contacts. The varistor ensures that no high voltage is imposed on the contacts.

-Diode: the energy stored in the coil is converted into current by the diode connected in parallel to the load. Then the current flowing into the coil is consumed and the Joule heat is generated by the resistance of the inductive load. The diode must withstand a maximum reverse voltage 10 times greater than the circuit voltage and a forward current equal to or greater than the load current.

-Diode and Zener Diode: This method will be effective if the reset delay caused by the diode method is too long. The Zener voltage for a Zener diode should be approximately 1.2 times that of the power supply.

Make sure the operator body works smoothly. The shape must be round or oblique to avoid impact on the actuator. And of course, operate the actuator of a hinge roller lever or simulated hinge lever type from the correct (correct) direction.

Make sure the actuator travel is set not to exceed the full travel position.