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2 Jul 2015

obr1723_1

Without problems and directly at connecting a device. How? With a new Euroclamp MPF03 terminal block with integrated fuse holder.

Nowadays, when “almost everything” works on electricity we can see still more devices connected to mains line. That´s why it often happens, that many small-power devices are connected to one (circuit breaker fused) line. To increase a safety, it´s usually advantageous to fuse particular devices separately – for example by small glass fuses. Somewhere it´s advantageous on a panel or directly on a PCB, elsewhere directly in a control relay interface module and in many cases directly in a place of connection.

For this purpose a novelty in our offer is very suitable – 3-pole terminal block MPF03-10, where one of poles is fused by a glass tube fuse 5x20mm. In praxis it can look so, that on a place where you so far used a classic (“chocolate”) terminal block, you can use MPF03 and insert a suitable fuse.

In the MPF series can be found series with 1-5 poles. As already a name says, pin spacing (pitch) of the MPF series is 10mm. On stock we have the 3-pole version MPF03-10 ideally suitable for mains line appliances (L,N,PE). Exact dimensions and further parameters can be found in the Euroclamp MPF03-10 datasheet.


Add a fuse where it´s desirable – [Link]

8 Apr 2015

obr1489_1

With thermal fuses you´ll make a big step towards a higher safety of your device.

It´s surely not necessary to remind that any device can fail. Failure of a component, overload of a component (underestimated sizing), external influence and many other reasons are daily causing failures of devices. If the result of a malfunction is only an intermediate shutdown, it´s let´s say a better case. But if a device malfunction could cause further damage or even fire, it´s surely worth to make everything possible to prevent it.

A typical component used as a complementary – independent protection from overheating is a thermal fuse. It is a cheap but very useful component, which opens (disconnects) a circuit after exceeding certain temperature. It is a “one shot” component, i.e. after its activation it remains open and the fused circuit is disconnected (the fuse must be exchanged). It´s suitable to choose such fusing temperature of the fuse, as we consider to be really faulty, which otherwise can´t occur in an ordinary operation. Production processes enable to produce thermal fuses in a wide range of temperatures and so fuses Microtemp from company Thermodisc, which we keep in stock, are available in a range of 72-257°C (opening temperature). It´s a really wide range enabling to use a fuse for example for fusing of other component (for example a thermal fuse thermally joined with a transistor heatsink) but also for guarding an air temperature inside a device. These fuses operate on a principle of melting a small plastic pellet inside a fuse, what will cause release of a spring and a consequent disconnection of contacts.

A substantial advantage of thermal fuses Thermodisc is a maximum current up to 10-25A/250VAC depending on a type. On stock we keep the G4 series with a max. current of 10A/250VAC. Small dimensions enable to use a component similarly like any ordinary component. It´s only necessary to be careful at assembling (overheating) especially at low-temperature types.
Details regarding a correct assembly as well as an overview and tips for a correct use of thermal fuses can be find in the Thermodisc application guide. Teplotné poistky sú dostupné aj v iných púzdrach, prípadne aj s nožovými kontaktmi (Fast-on). Thermal fuses are also available in other packages, or also with tabs (Fast-in). Finally, we can mention, that to reach the highest protection level in critical application, it´s ideal to incorporate several types with a slightly different fusing temperature in series.


They act only ones – right then, when it´s really necessary – [Link]

10 Mar 2014

obr1489_1

It´s surely not necessary to remind that any device can fail. Failure of a component, overload of a component (underestimated sizing), external influence and many other reasons are daily causing failures of devices. If the result of a malfunction is only an intermediate shutdown, it´s let´s say a better case. But if a device malfunction could cause further damage or even fire, it´s surely worth to make everything possible to prevent it.

A typical component used as a complementary – independent protection from overheating is a thermal fuse. It is a cheap but very useful component, which opens (disconnects) a circuit after exceeding certain temperature. It is a “one shot” component, i.e. after its activation it remains open and the fused circuit is disconnected (the fuse must be exchanged). It´s suitable to choose such fusing temperature of the fuse, as we consider to be really faulty, which otherwise can´t occur in an ordinary operation. Production processes enable to produce thermal fuses in a wide range of temperatures and so fuses Microtemp from company Thermodisc, which we keep in stock, are available in a range of 72-257°C (opening temperature). It´s a really wide range enabling to use a fuse for example for fusing of other component (for example a thermal fuse thermally joined with a transistor heatsink) but also for guarding an air temperature inside a device. These fuses operate on a principle of melting a small plastic pellet inside a fuse, what will cause release of a spring and a consequent disconnection of contacts.

A substantial advantage of thermal fuses Thermodisc is a maximum current up to 10-25A/250VAC depending on a type. On stock we keep the G4 series with a max. current of 10A/250VAC. Small dimensions enable to use a component similarly like any ordinary component. It´s only necessary to be careful at assembling (overheating) especially at low-temperature types.
Details regarding a correct assembly as well as an overview and tips for a correct use of thermal fuses can be find in the Thermodisc application guide. Thermal fuses are also available in other packages, or also with tabs (Fast-in). Finally, we can mention, that to reach the highest protection level in critical application, it´s ideal to incorporate several types with a slightly different fusing temperature in series.

They act only ones – right then, when it´s really necessary… – [Link]

3 Nov 2013

obr1417_uvod

Resettable fuses are a very useful complement significantly increasing a safety of devices.

Polyswitch-es provide a big service at protection of devices, where they behave like „resettable“ fuses. How many times it is suitable or necessary to use a fuse in a device, but a relatively bulky fuse socket simply doesn´t have a space in our device (or it would spoil a device design) and we also don´t want to use a PCB fuse holder, because a device would have to be constructed as user accessible… Then and not only then, is the ideal solution to use a Polyswitch. Such „fuses“ are available from various producers (for example also under names Polyfuse, Multifuse), Polyswitch is a trade name of company TE Connectivity/ Raychem, representing a top level in this segment.  In a principle, a Polyswitch is a PTC resistor with a Polymeric structure designed for a big change of resistance in a narrow temperature range. Conductive particles are dissipated in an amorphous polumer, which changes its structure at a higher temperature (melts), increases its volume resulting in a rapid increasing of a component resistance. In this point (tripping point) a very rapid increasing of resistance appears, which is high enough, so that a leakage current is practically negligible and won´t cause a damage to a protected circuit. Each Polyswitch has a defined holding current (I hold), nominal resistance at a given temperature and tripping (switch off) current (I trip). By a current flowing through a Polyswitch, it gets calorified (I2R), until a certain current it will reach a level, where a rapid increasing of its resistance appears. An exact current at which this change arises naturally depends also on an ambient temperature (at higher temperature a lower current is sufficient). This behavior is digestedly illustrated on an enclosed graph (Fig.4). In the A region, a Polyswitch is switched off (tripped) and a device is disconnected. In the region B the Polyswitch allows for normal operation (on) at any combination of a current and ambient temperature. In the region C can the component go tripped (off) so to say “anytime” depending on a concrete resistance value of a given piece. Read the rest of this entry »


22 May 2010

Have you programmed the wrong fuses and now you can’t access your AVR? No problem there is a solution out there. All you need is a high voltage programmer to reset fuses. This board called “Fuse doctor” can reset your fuses. Programmer supports ATTiny2313, ATmega8, ATmega16/32 and others. One great feature is that it doesn’t need computer to operate. [via]

Wrong AVR fuses? Correct them using fuse doctor – [Link]



 
 
 

 

 

 

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