Switches

What is the IK impact resistance rating?

Initially related to the IP sealing test, the Ik rating became a specific rating to measure the impact resistance of product in 1995. It is now related to the EN 62-262 European standard.
This rating can be decisive in a product selection. It doesn’t rate the mechanical life but the capacity of a product to face environmental aggressions. Therefore it is a key feature for any product intended for consumer goods.

IK The IK impact resistance is rated through a specific test carried out with a “Charpy pendulum” impact tester.

This device measures the resistance of a product submitted to 3 repeated identical impacts.

The impact energy (in joules) depends on 2 elements:

- The distance between the hammer and the tested sample

- The hammer weight

According to the resistance level rated during the test, an IK code is assigned to the product. This code ranging from IK0 to IK10, determines the energy level the product can absorb.

IK00 Not protected
IK01 Protected against 0.14 joules impact.
Equivalent to impact of 0.25kg mass dropped from 56mm above impacted surface.
IK02 Protected against 0.2 joules impact.
Equivalent to impact of 0.25kg mass dropped from 80mm above impacted surface.
IK03 Protected against 0.35 joules impact.
Equivalent to impact of 0.25kg mass dropped from 140mm above impacted surface.
IK04 Protected against 0.5 joules impact.
Equivalent to impact of 0.25kg mass dropped from 200mm above impacted surface.
IK05 Protected against 0.7 joules impact.
Equivalent to impact of 0.25kg mass dropped from 280mm above impacted surface.
IK06 Protected against 1 joules impact.
Equivalent to impact of 0.25kg mass dropped from 400mm above impacted surface.
IK07 Protected against 2 joules impact.
Equivalent to impact of 0.5kg mass dropped from 400mm above impacted surface.
IK08 Protected against 5 joules impact.
Equivalent to impact of 1.7kg mass dropped from 300mm above impacted surface.
IK09 Protected against 10 joules impact.
Equivalent to impact of 5kg mass dropped from 200mm above impacted surface.
IK10 Protected against 20 joules impact.
Equivalent to impact of 5kg mass dropped from 400mm above impacted surface.

APEM’s integrated test laboratory carries out IK impact resistance tests in accordance with the specifications of the EN-62-262 standard.

How to get the tactile feedback you want:

The first step in getting the right feedback is asking the right questions:
  • How much space do I have for the switch?
  • Will it be constantly or infrequently actuated?
  • How distinct do I need the actuation signal to be? How strong?
  • Will the device be subject to vibration?
  • Will it need to be environmentally sealed?
  • How long a life must it have?
  • How great a consideration is cost?
Tactile feedback can be achieved via a spring mechanism, a metal dome or a polyester membrane. With all three materials, deforming the initial and preferred state of the device enables contact with a switch actuator. But that’s where the similarity ends, and choosing between the options is a lot easier when you know the strong and weak points of each type. Tactile feedback mechanisms vary greatly as to cost, reliability and feel. But perhaps most importantly, they require varying degrees of force and travel (pressure and distance) to engage the switch. These last two variables impact the life expectancy of the device and the ease of use for the end user. The tactile feedback of a computer keyboard switch, constantly in use and requiring little force, should not resemble that of a forklift safety switch, where gloved, infrequent use calls for significant resistance and a highly charged feedback.

Here’s a cheat sheet from APEM engineers:

Force-stroke curve of a horizontally positioned spring based tactile feedback mechanism
Spring mechanisms:The performance of spring based mechanisms is dependent on the positioning of the spring within the device.

Vertically positionedspring mechanisms are engaged simply by depressing the spring. It is the most versatile of the tactile feedback mechanisms in that it can accommodate a long travel distance or be used in large switches. It bears up well in frequent use, with a maximum life of 10million cycles. The “feel” of a vertically placed spring mechanisms is always less satisfying than that of domed mechanisms or horizontally positioned spring mechanisms since there is no precise indication of actuation, no “snap”. Vertically positioned springs can suffer from inadvertent activation in high vibration applications.

Horizontally positioned spring mechanisms have a distinct tactile feedback which is accompanied by a metallic clicking sound at the moment of actuation. These mechanisms hold up well in environments where they are subject to vibration or strong current.
Both vertically and horizontally positioned springs often require combination with a membrane to achieve an effective front seal.

Force-stroke curve of a metal dome based tactile feedback mechanism.
Metal dome mechanisms: metal domes are formed out of stainless steel that, when compressed, collapses, actuates the switch, and then releases to its initial convex configuration. Metal domes provide a great deal of positive response, giving the user a crisp, precise activation signal. They are, however, size limited: past 16mm, the metal cannot be reliably counted on to properly return to its initial configuration. Metal domes provide superior tactile feedback and usually carry the highest price tag.

Force-stroke curve of membrane based tactile feedback mechanism.
Membrane mechanisms : In membranes, the inside of a polyester bubble is coated with graphite. Membranes can reliably function at larger sizes than metal domes and are typically less expensive. The feel of a membrane is less precise than metal, because the collapsing dome doesn’t provide as much positive response. This can be advantageous in high repetition uses, where transmitting too much energy back to the user can be ergonomically disadvantageous. Although still size limited, membranes can be effective in larger sizes than metal domes and usually have a longer life span. Membranes can be configured into virtually any shape, sealing the switch without additional components.
All tactile feedback devices need to be calibrated for the intended end use. APEM QA uses a Force Stroke Machine to ensure our tactile feedback mechanisms are fine tuned.

What’s the right sealing approach for my specifications?


Switches can be sealed several, or in a combination of, ways, with each approach having advantages in certain applications. Buying a higher sealing level than required to ensure performance to specification is costly: increased levels of protection mean higher component costs and a more complicated assembly process.

Avoid over engineering by knowing which approach best fits the required task:

Integrated seal on the switch
This option provides really excellent sealing. Switches can be independently sealed above and beneath to practically any standard, including IP69. Since the switching mechanism is fully sealed, this is a good choice for standalone applications where the switch itself is exposed to a harsh environment. Tractor, crane and heavy industry switches, and other applications where the switch is directly mounted are typical examples. It is also really the only option when safety is a prime consideration and there is concern about the sealing integrity of a box the switch will be housed in.

Most APEM switches are available in fully sealed options. APEM switch series that can be independently sealed to IP69 include PBA (in illuminated or non illuminated versions), the 3500 series, the IP series (non illuminated version), AV9S and AV3S.

Front panel sealing

Good at preventing fluids and particles from entering into or behind the box or panel. Used primarily when the switch is part of a larger, more sophisticated product where additional, potentially fragile components may be housed in with the switch. The switch itself can be sealed or unsealed, depending on the required use. If the box housing the switch is fully sealed, it is often not necessary to incur the additional expense of a fully sealed switch. Note that when a fully sealed switch is housed in a sealed front panel, requirement testing must be conducted separately on the switch and then on the switch housed in the panel. Most APEM switches can be front panel sealed.




Sealing boots

A relatively low tech option that does the same job as a font panel sealing and is a good choice when budget is a issue. It is also useful as a retrofit on an existing product experiencing sealing issues. APEM sealing boots can be used with most APEM switches. (Note that sealing boots are susceptible to cuts from sharp objects, making them an inappropriate choice in some environments).






What is RoHS ? Do APEM switches comply with this standard?

The RoHS Directive stands for "the restriction of the use of certain hazardous substances in electrical and electronic equipment".  This Directive bans the placing on the EU market of new electrical and electronic equipment containing more than agreed levels of lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyl (PBB) and polybrominated diphenyl ether (PBDE) flame retardants.

All APEM switches comply with the RoHS requirements.

What is IP69K protection?

The goal of this test is to simulate pressure cleaning conditions on a plant floor. In the test fixture, the switches German standard DIN 40050-9 extends the IEC 60529 rating system with an IP69K rating for high-pressure, high-temperature wash-down applications. Such enclosures must not only be dust tight (IP6X), but also able to withstand high-pressure and steam cleaning. The test specifies a spray nozzle that is fed with 80°C water at 8–10 MPa (80–100 bar) and a flow rate of 14–16 L/min. The nozzle is held 10–15 cm from the tested device at angles of 0°, 30°, 60° and 90° for 30 s each. The test device sits on a turntable that rotates once every 12 s (5 rpm).

The IP69K test specification was initially developed for road vehicles, especially those that need regular intensive cleaning (dump trucks, cement mixers, etc), but also finds use in other areas (e.g., food industry).








IP69K

Cycle of 30 seconds
14 - 16 litres per minute
water 80°C
80-100 bar




How do I choose my APEM Switch?

The following features are the most important :
- Mounting
- Actuator type
- Current Rating
- Environment (sealing, ..)

What about obsolescence? Is it possible to find an old APEM series?

APEM as a man machine interface manufacturer since 1952 is able to supply you an old product manufactured 50 years ago! This is a real advantage for our customers in Aeronautics industry and Military industry.

Where are “S” contact option for high inrush current. Are they still available ?

These products are still available. Please consult us.

My application is subject to frost. Has APEM any specific product?

The 3500 toggle switch series and the IA pushbutton series are specifically dedicated to frost environments. Also the PBA piezoswitches, with their sealed construction and no moving part are resistant to frost.

Switches  Switches Switches

What is IP rating?

The IP Code (or International Protection Ratingsometimes also interpreted as Ingress Protection Rating) consists of the letters IP followed by two digits and an optional letter. As defined in international standard IEC 60529, it classifies the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in electrical enclosures. The digits ('characteristic numerals') indicate conformity with the conditions summarized in the tables below. Where there is no protection rating with regard to one of the criteria, the digit is replaced with the letter X.

IP Ratings

What is the typical IP rating of a unsealed APEM product?

IP40.

What is UL94-V0?

UL 94 is a plastics flammability standard released by Underwriters Laboratories of the USA.

The standard classifies plastics according to how they burn in various orientations and thicknesses. From lowest (least flame-retardant) to highest (most flame-retardant), the classifications are:

  • HB: slow burning on a horizontal specimen; burning rate < 76 mm/min for thickness < 3 mm.
  • V2 burning stops within 30 seconds on a vertical specimen; drips of flaming particles are allowed.
  • V1: burning stops within 30 seconds on a vertical specimen; no drips allowed.
  • V0: burning stops within 10 seconds on a vertical specimen; no drips allowed.
  • 5VB: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may develop a hole.
  • 5VA: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may not develop a hole.

What are typical switch application ?

 Please visit our page dedicated to our product applications.

How to estimate a current rating for inductive loads?

Is there any empirical mean? One possibility is to divide the rating under a resistive load by 2. It’s a good estimation.

Does APEM have switches with UL agreements?

Yes. The following series (some models within these series) meet these requirements: Ax, AS, AV, FM, S, SP, 1200, 13000, 1500, 2200, 25000N, 2600, 3600, 4100-4200, 4600, 4700, 5000, 55000, 57000, 600H, 600NH, 7000, 8000.

How to supply LED of illuminated switches?

A resistor must be serial-connected to the LED. If the resistor is integrated into the product (LPI, KR, KL) you only have to supply the appropriate DC voltage. On the other series, a resistor has to be serial connected to the switch. APEM gives the LED forward voltage and the LED forward current in the series brochure (depending on the colour, the brightness) to calculate the resistor value:

Resistor value = supply voltage - LED forward voltage 
                               LED forward current
On the IP and IR series, the resistor can be integrated into the product by APEM. Consult us.

What is the standard gold thickness on a plated contact?

0,65 µ

What is the stainless steel grade used on APEM products?

303 and 316L otherwised specified.

The 303 is a free machining version of 304 via addition of sulfur.  The type 316 is the next most common; for food and surgical stainless steel uses; alloy addition of molybdenum prevents specific forms of corrosion. 316 steel is used in the handling of certain food and pharmaceutical products where it is often required in order to minimize metallic contamination. 316 steel is also known as "marine grade" stainless steel due to its increased ability to resist saltwater corrosion compared to type 303. 
 
SAE designation UNS designation %Cr %Ni %C %Mn %Si %P %S %N
316L S31603 16–18 10–14 0.03 2 0.75 0.045 0.03 0.10
303 S30300 17–19 8–10 0.15 2 1 0.2 0.15 min -



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Tel B : (+32) 27 25 05 00
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e-mail: inquiries@apem.be