Engineers searching for electromechanical switches that are truly waterproof are generally doing so for a few common reasons:
- Their switch will be used outdoors. (ie. Lawn mowers, generator, etc…)
- Their switch may be fully submerged for periods of time. (Military Humvee’s, recreational vehicles, boating applications)
- Their switch has to be both waterproof and heavy duty to avoid general failure due to salt water, wind, sand spray, and other airborne or liquid particulates that may be flying around.
In these applications, failure of the switch can often compromise the safety of equipment, its use around people, or even cause catastrophic failure of the machine. In less severe situations, failure may simply be a royal pain-in-the-neck due to difficulty replacing the part in the field and the cost of a potential in-warranty failure.
The Top Reasons Waterproof Switches Fail
There are a few things manufacturers do to cut corners on the design and manufacturing of so-called “waterproof switches”, that can cause early failure:
- Poor Seal Integrity when actuated – A waterproof switch has its most vulnerable moments when the plunger is actively depressed. Over time particulates present in the air or water will seep into the switch, destroying its integrity, and causing the part to fail.
- Switches are only really water-resistant, or “splash-proof” – It turns out that these low cost waterproof switches were never really designed for prolonged submersion in water at any depth. So repeated dunking under water or repeated splashes causes early failure.
- Rusting or decay of internal parts or seal by corrosive contaminants – Exposure to hot oil, gasoline, grease, glue, etc… over time is not the friend of most waterproof switches.
- Improper Mounting – Many manufacturers make you shoe-horn their one-size-fits-all switch into your application. This can put the electromechanical switch actuator in a sub-optimal position and cause substandard electromechanical endurance.
- Wire Failure – At some point, wires have to actually leave the switch and the seal around them as well as the selection of insulation and the path they run back to your control system is critical to the long term performance of the sensor in your application.
The CPI Waterproof Switch Solution Examined
In solving these critical issues over the last 70 years of making waterproof switches, CPI has developed some fairly unique (and patented) engineering and manufacturing solutions for the making of waterproof limit switches that are truly waterproof, electromechanically hardened, and economically manufacturable right here in the USA.
- Patented Double Seal Design – Our J4 Ball carrier design for instance, uses a
patented double seal coupled with precise manufacturing which actually forces moisture and particulates out of the system every time the plunger is released. This design has been tested to 5 million cycles without failure and continues to replace failed switches around the world in harsh duty applications. - Our line of sealed Limit Switches seals the plunger in either Neoprene or Santoprene to allow for extended temperature operation as well as a seal integrity that has proven to be most airtight and watertight design in the world.
- Top grade corrosion resistant Stainless Steel used in all parts…period. If you’re selling waterproof switches and trying to save pennies on manufacturing it’s common to back off on the quality of the stainless you’re using. We don’t. All our switch actuators are made of 17-7ph stainless and our brackets are made of 302 or 304 stainless for additional corrosion resistance.
- Mounting Options Galore – CPI waterproof switches have more mounting options and predesigned brackets than any switch on the market. Roller mounts, simulated roller, lever, pipe mounts, right/left angle mounts, and dozens more variations. And then of course, there’s the opportunity for us to make you a custom mount/actuation bracket for your unique application. When it comes to mounting our waterproof switches, we’ve really got you covered.
- Variable lead length – CPI will actually manufacture the lead extensions from your switch to whatever length you need. These leads are sealed inside our switches by the neoprene or santoprene covering, using a proprietary manufacturing process which produces them perfectly sealed every time.
Try Something Made Better – CPI Waterproof Switches
If you’ve got an application that you think might be better served with one of our truly waterproof ball, plunger, or limit switches, don’t be shy give us a call. We can get some samples out to you right away, and our engineers love to discuss new applications for our switches.
Call 973.887.9400 today and ask for our Waterproof Switch Application Team.
Original content posted on https://www.cpi-nj.com/blog/top-5-reasons-your-waterproof-switches-arent/
According to sources with combat experience, the RPG is most typically a “100-yard weapon”. Adversaries know that to be effective, the RPG needs to be fired at close range. The RPG-7’s maximum flight velocity is around 300 meters per second, so assuming roughly 100 yards to target, it could take as little as 300 milliseconds from launch to impact. Given that any (aimed) active defensive system must detect the inbound threat, classify it, process a response, and aim and launch the countermeasure before the threat makes contact; a realistic system design goal would require the aiming mechanism to be capable of addressing a threat from any direction in 100 milliseconds or less. There is presently no traditional “gun and gimbal” turret system that can aim this rapidly.
For RPG defense, a continuously-rotating countermeasure aiming and launching system provides a much faster response than a traditional “gun and gimbal” turret system. Many active RPG countermeasures are self-propelled munitions. They do not require robust gun barrels for launch. They may be launched from short tubes that are little more than storage capsules. Self-propelled munitions also do not produce significant recoil. We propose a design of a fast aiming-and-launch system in the form of a rotating drum. This drum-shaped countermeasure launch container houses multiple munitions, each in a short launch tube, in an outwardly-facing circular array. The circular array lies on a plane perpendicular to the drum’s axis. Given that the launch tube is only about as long as the munition itself, this circular array could be realized in a drum-shaped launcher whose overall diameter is slightly larger than twice the length of an individual countermeasure round. Rotating the drum about its axis creates a situation in which any point, or multiple points, on a planar azimuth of rotation are continuously brought into the line of fire of the munitions in the array. Any point within a full 360 degrees can be targeted in the time that it takes to rotate the nearest-available munition (array element) to that point. In one example, 8 countermeasure munitions are arranged in the outward-facing 360 degree circular array with munitions spaced equally every 45 degrees. In this example the drum must rotate (at most) 45 degrees in order to bring the nearest munition to any point around a 360-degree azimuth. Depending upon the rotational speed of the drum, the time required to bring munitions to bear could be on the order of milliseconds. The preceding description provides a rotational turret capable of firing 8 countermeasures. However a drum-shaped launcher suggests the possibility of superposing (stacking) multiple arrays of countermeasures. So a single drum-type launcher is capable of firing 16 or more defensive munitions prior to reloading and would not potentially require a second instantiation of the turret for multiple threat detection.
Further calculations on a drum that rotates about as fast as a ceiling fan (300 RPM), show that a countermeasure could be delivered to any point on the azimuth in 25 milliseconds or less. This is roughly the amount of time that it takes an RPG to cover about 7 meters.
Control Products, INC 