Design ready ? Start production ? Not just yet !

During the development process specifications are taken into account. And these specifications mention to which standards the product must comply and what certificates must be acquired.


Many standards are all about safety of the user. A few examples:

CE low voltage directive, at first sight low voltage is confusing here. The machines that must comply to this standard use voltages between 42 V and 1.000 V. Really from the point of view of power engineering 1.000 V is a low voltage. The low voltage directive demands guarantees for the user that a dangerous situation can never occur, even if the product contains a single fault. A single fault for instance is a loose mains wire. Such a fault may never lead to a dangerous situation. Dangerous means here: “a mains voltage is present on a conductor that the user can touch” or “causing overheating or fire”.

Medical devices, are used on or by patients, in some cases even electrodes are connected to the human body. Equipment used for patients must comply to higher standards than ordinary consumer goods. Especially when electrodes are used the standards are high. In this case too guarantees must be given that a fault situation never causes the electrical current, that flows through a patient, to rise above a safe level. A fault here can be: “the insulation of a transformer is defective”. Even so a patient may never be subjected to a dangerous current in spite of this fault.

CE machine directive, gives a programme of requirements to guarantee safe operation of machines.A knife is meant to cut, an industrial cutting machine too, but it has to be operated in a safe way. A safe way for instance can be realized by placing a switch both on the left and on the right side of the machine. In that case you need two hands to operate the machine, so your hands can never be under the knife. Unless someone else lends a hand…. To prevent that the cutting mechanism must be equipped with a sensor that detects there is something under the knife that doesn’t belong there. Safety guarantees. As far as reasonably possible.


CE EMC emission directive, “Thou shall not disturb others”. Electrical machines produce electro magnetic fields.That is how it is when an electrical current flows. In some cases the product was meant to transmit electromagnetic waves. Think about radio transmitters, cellular phones and micro wave ovens. In most cases the product was not meant to transmit and it needs to comply to strict standards. A good design takes this into account, but approval is still necessary.

CE EMC immunity directive, “Thou shall not be sensitive to interference from others”. Electrical machines produce electro magnetic fields. Including the product that is lying next to you. If that product complies to the emission directive and thus keeps its emission low, your product should not be sensitive to this level of emission. And just as well electrostatic discharges, caused by humans, should not degrade the correct functioning of a product. A good design takes this into account, but approval is still necessary.

We don’t approve ourselves, thats why there are test houses and approval institutes. And it is a good thing to have your product approved by an independent third party.