Soft Start

[Aleksandar Car]

Nisam siguran kad se kaze izvor dal se misli na izvor zvuka ili napajanja...Ako ne odgovara topik mestu, molim moderatore da ga pomere. Uglavnom ovu semicu sam nasao i odusevio se jednostavnoscu. Eto vam je pa ...

[pile]

Napravio par komada i shvatio da se ne isplati praviti za jednu crvenu.

http://www.trafco.co.yu/softstart.php

[Aleksandar Car]

Napravio par komada i shvatio da se ne isplati praviti za jednu crvenu. http://www.trafco.co.yu/softstart.php

Niko ne spori taj dizajn, ali ovo me odusevljava, jer nema releja i struja kroz prekidac je mala (samo za punjenje kondenzarora).

[Ја sam sam]

Где нађе ту руску шему, или нека од бивших република источног блока?Лично ми је јадна, ипак мислим што каже Пиле за 10Евра код Трафка је јефтиније.Мада, а што не употребити релеј?стоН_Колд

[Fukushima]

Nisam siguran kad se kaze izvor dal se misli na izvor zvuka ili napajanja...Ako ne odgovara topik mestu, molim moderatore da ga pomere. Uglavnom ovu semicu sam nasao i odusevio se jednostavnoscu. Eto vam je pa ...

Ne bih rekao da to moze bas tako da radi...

[Aleksandar Car]

Ne bih rekao da to moze bas tako da radi...

A sto??? Ljudi tvrde, a i moje skromno znanje elektronike takodje podrzava da bi to bas tako trebalo da radi!!!

[BlueSky]

Aco, uzmimo za primer da je kolo tek prikljuceno na mrezni napon. Napon na kondezatoru je jednak nuli. Recimo da krene jedna poluperioda naizmenicnog napona, bilo pozitivna ili negativna je nebitno zbog greca. Maksimalna vrednost na kolektor-emitoru tranzistora iznosi oko 310V. Naponski razdelnik je podesen da na kondezatoru da 272V. Dakle, kondezator od 1000u se puni na napon od 272V preko unutrasnje otpornosti razdelnika koja ovde iznosi 90 oma. Ali se kondezator nece nikada napuniti na tu vrednost je ce pri naponu od 0.6V na kondezatoru poceti da vodi tranzistor. Dakle, potrebno je da izracunamo koje vreme je potrebno da se dostigne napon na kondezatoru od 0.6V ako se puni iz izvora od 272V i unutrasnje otpornosti od 90 oma. t= RC ln ( 272 / (272 - 0,6)) => dobija se oko 200usDakle, od soft starta nema nicega. Kolo ce skoro trenutno ukljuciti transformator. Sema nije ispravna, ali ideja nije losa.Simulacija potvrduje to. (Plava je mrezni napon, zelena napon na transformatoru)

[Mikorist]

Napravio par komada i shvatio da se ne isplati praviti za jednu crvenu. http://www.trafco.co.yu/softstart.php

Koje su dimenzije ove plocice

[Aleksandar Car]

Aco, uzmimo za primer da je kolo tek prikljuceno na mrezni napon. Napon na kondezatoru je jednak nuli. Recimo da krene jedna poluperioda naizmenicnog napona, bilo pozitivna ili negativna je nebitno zbog greca. Maksimalna vrednost na kolektor-emitoru tranzistora iznosi oko 310V. Naponski razdelnik je podesen da na kondezatoru da 272V. Dakle, kondezator od 1000u se puni na napon od 272V preko unutrasnje otpornosti razdelnika koja ovde iznosi 90 oma. Ali se kondezator nece nikada napuniti na tu vrednost je ce pri naponu od 0.6V na kondezatoru poceti da vodi tranzistor. Dakle, potrebno je da izracunamo koje vreme je potrebno da se dostigne napon na kondezatoru od 0.6V ako se puni iz izvora od 272V i unutrasnje otpornosti od 90 oma. t= RC ln ( 272 / (272 - 0,6)) => dobija se oko 200usDakle, od soft starta nema nicega. Kolo ce skoro trenutno ukljuciti transformator. Sema nije ispravna, ali ideja nije losa.Simulacija potvrduje to. (Plava je mrezni napon, zelena napon na transformatoru)

sve si apsolutno u pravu!!! Jedino sto je greska to je da tamo verovatno ide 100koma a ne 100 oma... Mislim da je greska u crtanju seme. Nisam se udubljivao u analizu, nego sam gledao koncept koji mi se svidja jer nema prekidackih elemenata kroz koji protice veca struja nego su to male vrednosti, a nema ni releja kojeg ne volim u elektronici!

[Impuls]

Sad cu ja da pitam kao laik da bi svi razumeli. Soft start bi trebao da napuni elektrolite pri paljenju a tek tada da prabaci na redovan rad. Posto u trenutku ukljucenja struja primara protice kroz otpornike od 100 i 1k, smatram da je to jako mala struja da bi se napunili elektroliti. Nakon punjneja elka provede tranzistor i kroz njeg aprolazi struja primara. Ako bi se stavio 100k umesto 100 oma tranzistor ne bi uspeo da bude u zasicenju i vrlo brzo bi vrisnuo. Sledeci problem je kada tranzistor udje u zasicenje njegov kolektor pada ispod naponskog nivoa baze. sta ce u tom slucaju da odrzi tranzistor u zasicenje? Znaci tranzistor radi u aktivnom rezimu. Ako na tranzistoru bude napon oko 2V u trenucima kada kroz elektrolite treba da prodje velika struja iz trafoa i kroz primar prolazi velika struja, baza tranzistora zahteva zbog malog strujnog pojacanja veliku struju koju ne moze da dobije kroz 100k. I tako u krug. Malo mi nejasna sema ali kad kazete da radi poverovacu. Mozda bi ovo lakse funcionisalo sa tiristorom?

[BlueSky]

Da, da...otpornik od 100k, takode, nece biti dobar.

[Aleksandar Car]

Tako je u pravu ste momci... sa tiristorom bi moglo, ali sa izmenama u semi... i malo bi bilo problematicno gasenje istoga.

[Zen Mod]

Koje su dimenzije ove plocice

Miko - tebi ne treba nista sem NTC-a.mali je to trafo

[Daudio]

...... Uglavnom ovu semicu sam nasao i odusevio se jednostavnoscu. Eto vam je pa ...

Da li cu pomoci ako ti kazem da su KC405A,verovao ili ne zenerice 5,9-6,2v.Tako to stoji sa rusima,obzirom da je cirilica u pitanju ono c je ustvari С,а не Ц.Pod oznakom KC405A se nalazi ni manje ni vise doticna zener dioda.Moze li link ka toj semi,jer me zanima sta su sad bacuske smislile?Pitam se da li bi to moglo da radi u slucaju da je na elktrolitu svega 5-6v,umesto 270v i da se uzima samo toliko malo napona.Sad ko jos radi gretc sa zenericama ?Opet tranzistor KT812A je za samo 400v i 8A,tako da je i to vrlo malo za varijantu 270v na bazi,pitam se sta bi bilo u naponskim pikovima-verovatno bi probio.Zanimljivo cudna sema,svojstvena ruskim razmisljanjima,tako da me ne bi iznenadili da to ipak i moze da radi-samo kako.U svakom slucaju,ko se ne razume dovoljno u rusko govorno podrucje,ne uzimati sve zdravo za gotovo.

[Aleksandar Car]

Zanimljivo cudna sema,svojstvena ruskim razmisljanjima,tako da me ne bi iznenadili da to ipak i moze da radi-samo kako.U svakom slucaju,ko se ne razume dovoljno u rusko govorno podrucje,ne uzimati sve zdravo za gotovo.

eve linakhttp://datagor.ruJa ochenj harasho govorju russki jazik!

[Daudio]

eve linak

http://datagor.ru

Ja ochenj harasho govorju russki jazik!

Aco,care,vrlo dobro nije ni blizu odlicno,a sem toga postoji i ono citam,pisem....

Salim se naravno.

Ruski sam izucavao 9 godina,profesorica mi je cak bila i ruskinja,radim na ruskoj tehnici preko decenije(podrazumeva se literatura na ruskom),u kontaktu sam sa rusima,pa jos uvek se ne usudjujem da izjavim kako vrlo dobro govorim ruski.

Ali kako nisam ja predmet rasprave,da se vratimo na doticnu semu.....

Citao jesi,ali si izgleda pretrcao preko najvaznije stvari.Lik je krenuo sa tom semom gde i sam pominje sledece:

Приведенные номиналы делителя несколько смущают

[Aleksandar Car]

Aco,care,vrlo dobro nije ni blizu odlicno,a sem toga postoji i ono citam,pisem....

Salim se naravno.

Ruski sam izucavao 9 godina,profesorica mi je cak bila i ruskinja,radim na ruskoj tehnici preko decenije(podrazumeva se literatura na ruskom),u kontaktu sam sa rusima,pa jos uvek se ne usudjujem da izjavim kako vrlo dobro govorim ruski.

Ali kako nisam ja predmet rasprave,da se vratimo na doticnu semu.....

...

Dakle Aco Care,kao sto sam i mislio ovo ne treba uzimati u razmatranje jer je covek izneo samo zamisao,a nije se udostojio ni da postavi ispitanu semu.

Pozdrav

Da se vratim na pocetak, nisam rekao da sam probao semu, kao ni da sam je analizirao, nego sam rekao da mi se sema ucinila zanimljivom. A za ruski pa vidis da sam turio smajli pored... We can continue on english as well as serbian... Da sam citao pazljivo - nisam! Sad vidim da ni sam autor nije doterao stvar do kraja, ali i dalje ostajem na stanovistu da je ideja odlicna.

Pozdrav.

[Ја sam sam]

Ма идеја је сигурно добра али изгледа смо у Рисији.From Russia with Love, што би рекао 007.стоН_Колд

[guja011]

svako umetanje silicijuma na putu od mreze ka primaru trafoa je jako zanimljivo.mozda releji jesu skljocare ali predstavljaju najbolji tacnije najcistiji spoj. i nije soft start, nego najobicnije izbegavanje strujnog pika uglavnom torusnog jezgra.

[stein]

http://www.edn.com/article/CA6462562.htmlhttp://en.wikipedia.org/wiki/Inrush_current_limiterhttp://www.ametherm.com/ What Is Inrush Current?How Is Inrush Current Limited?Passive or Active Protection for Inrush Current?There are several component options for inrush current limiting. The two most common alternatives are the use of NTC (Negative Temperature Coefficient) thermistors or various forms of active circuits. However, the most appropriate inrush current suppression technique for a particular application depends on component pricing issues, the equipment's power level, and the frequency at which the equipment is likely to be exposed to inrush currents. No single component solution can be best for every application. Each approach has its own advantages and disadvantages.inrush current limiterWhat is an Inrush Current Limiting Thermistor (Surge Limiter)?Inrush Current Limiters are among the most common design options used in switching power supplies to prevent damage caused by inrush current surges. A thermistor is a thermally-sensitive resistor with a resistance that changes significantly and predictably as a result of temperature changes. The resistance of a Surge Limiting thermistor decreases as its temperature increases. As the inrush current limiter self-heats, the current begins to flow through it. Its resistance begins to drop and a relatively small current flow charges the capacitors in the power supply. After the capacitors in the power supply become charged, the self heated inrush current limiter offers little resistance in the circuit. So low that the voltage drop is an insignificant factor with respect to the total voltage drop of the circuit.What types of Inrush Current Limiting Thermistors are available?Inrush current limiters are available in a wide range of initial resistance levels and current carrying capabilities. Ametherm produces inrush current limiters ranging from .2 to 220 ohms of initial resistance. Some designs are rated for less than one ampere while other are rated for up to 36 amperes.Are NTC Thermistors Common for Inrush Current Protection?A recent industry study, conducted by Data and Strategies Group, Inc., Framingham, MA, indicates that NTC thermistors are overwhelmingly the most popular type of device for inrush current suppression for power supplies. DSG's research indicates that NTC thermistors currently comprise more than 90% of the market for components for this purposeWhat about the cool down time of an Inrush Current Limiter?Because inrush current limiters heat after they suppress inrush currents, these devices require a cool-down time after power is removed. This cool-down or "recovery" time allows the resistance of the NTC thermistor to increase sufficiently to provide the required inrush current suppression the next time it is needed. An NTC's cool-down time varies according to the particular device, its mounting method and the ambient temperature. The typical cool-down time is roughly one minute.What are other uses of NTC ThermistorsNTCs are used for many other applications as well. Besides their usefulness in inrush current suppression, NTC thermistors' accurate temperature response, high stability and excellent reliability are well-suited to many other areas of electronic design. For example, they are often used in applications such as temperature measurement, temperature control, temperature compensation, voltage regulation, air-flow and liquid level sensing, and in creating time delay circuits.NTC thermistors for Inrush Current LimitingOne advantage of NTC thermistors over active circuits for inrush current suppression is lower component costs. inrush current limiters are typically less expensive than active circuit components. However, the exact cost of each component depends on the power level of the power supply for which it is intended. Typically, the higher the power level, the larger and more costly the component The cost advantage of inrush current limiters over active circuits can be easily illustrated with the following example based on a 300W power supply. To provide inrush surge protection with inrush current limiters, the only components needed are two inrush current limiters, at a total cost of $.80 or less for both thermistors.A second inrush current limiter advantage is a simpler design. Because inrush current limiter-based surge suppression circuits designs typically involve fewer components, they are less complex than those involving active circuits. In turn, a simpler design reduces the time needed to design the inrush current suppression capability of the power supply. As a general rule of thumb, using inrush current limiters for inrush current suppression requires only about one-fifth the time needed to design a comparable active circuit.Also, the inrush current limiter design provides greater manufacturing simplicity and lower reject rates. Fewer components means fewer assembly steps. A lower component count also decreases the potential for manufacturing rejects as a result of defective components.inrush current limiter-based surge suppression designs typically require significantly less space on the power supply circuit board than active circuits. For applications where the space available is at a premium, this can be a critical consideration.The failure mode when using an active circuit with a resistor usually requires component replacement. However, inrush current limiter-based in- rush surge suppression is self-protecting in the failure mode, because their resistance drops as temperature increases.Active Circuits For Inrush CurrentAs mentioned previously, various types of "active" circuits are sometimes used as alternatives to NTC thermistors (inrush current limiters) for certain applications. These component alternatives include triacs, resistors, and thyristors.An active circuit alternative is a triac (typically priced at about $1.00 for a 300W power supply), plus a resistor (about $.60), plus the circuit needed to drive the triac ($.20 or more) for a total of $1.80.Despite the economic and design simplicity advantages inrush current limiters offer for inrush current suppression, there are some situations when an active circuit may provide a more appropriate solution. For example, active circuits can sometimes be a better choice than inrush current limiters when "hot restart" capabilities are critical. The advantage is related to the cool down/recovery time required for the resistance of the inrush current limiter to increase sufficiently to provide the required level of inrush current protection. If the power drops out for a period shorter than the specified recovery time, say, for a few seconds, the thermistor will not have an opportunity to cool down and return to its initial level of resistance. When the power comes back on, the resistance is too low to provide sufficient inrush protection, so circuits could be damaged, fuses blown, etc.Active circuits offer lower power dissipation than inrush current limiters at higher power ratings (typically those above 300W). Because these designs typically run much cooler than NTCs, their heat dissipation/heat sinking requirements are lessCombination of NTC Thermistors and Active CircuitsThere is a design technique engineers can employ to eliminate the problems posed by the cool-down/recovery time required for inrush current limiters to return to their initial level of resistance. Essentially, this involves designing inrush current protection to drop the inrush current limiters out of the circuit after they have performed their function. By removing them from the circuit once the initial surge has passed, the thermistors have an opportunity to cool down, so they are ready to respond to a subsequent surge after a power drop-out occurs.This technique requires the addition of either a relay or a triac in parallel with the inrush current limiter, plus the circuits necessary to control it. All the components of the protection circuit would be in series with the input to the line. Once the inrush current has been absorbed by the thermistor, then either the triac starts firing or the relay closes. The simplest method of powering these components is from the power supply itself. Once the power supply starts, it closes the relay or fires the triac, dropping the thermistor out of the circuit and allowing it to cool down and regain its initial resistance, so it's ready to provide inrush current protection.ocete jos?

[Impuls]

http://www.edn.com/article/CA6462562.htmlhttp://en.wikipedia.org/wiki/Inrush_current_limiterhttp://www.ametherm.com/ What Is Inrush Current?How Is Inrush Current Limited?Passive or Active Protection for Inrush Current?There are several component options for inrush current limiting. The two most common alternatives are the use of NTC (Negative Temperature Coefficient) thermistors or various forms of active circuits. However, the most appropriate inrush current suppression technique for a particular application depends on component pricing issues, the equipment's power level, and the frequency at which the equipment is likely to be exposed to inrush currents. No single component solution can be best for every application. Each approach has its own advantages and disadvantages.inrush current limiterWhat is an Inrush Current Limiting Thermistor (Surge Limiter)?Inrush Current Limiters are among the most common design options used in switching power supplies to prevent damage caused by inrush current surges. A thermistor is a thermally-sensitive resistor with a resistance that changes significantly and predictably as a result of temperature changes. The resistance of a Surge Limiting thermistor decreases as its temperature increases. As the inrush current limiter self-heats, the current begins to flow through it. Its resistance begins to drop and a relatively small current flow charges the capacitors in the power supply. After the capacitors in the power supply become charged, the self heated inrush current limiter offers little resistance in the circuit. So low that the voltage drop is an insignificant factor with respect to the total voltage drop of the circuit.What types of Inrush Current Limiting Thermistors are available?Inrush current limiters are available in a wide range of initial resistance levels and current carrying capabilities. Ametherm produces inrush current limiters ranging from .2 to 220 ohms of initial resistance. Some designs are rated for less than one ampere while other are rated for up to 36 amperes.Are NTC Thermistors Common for Inrush Current Protection?A recent industry study, conducted by Data and Strategies Group, Inc., Framingham, MA, indicates that NTC thermistors are overwhelmingly the most popular type of device for inrush current suppression for power supplies. DSG's research indicates that NTC thermistors currently comprise more than 90% of the market for components for this purposeWhat about the cool down time of an Inrush Current Limiter?Because inrush current limiters heat after they suppress inrush currents, these devices require a cool-down time after power is removed. This cool-down or "recovery" time allows the resistance of the NTC thermistor to increase sufficiently to provide the required inrush current suppression the next time it is needed. An NTC's cool-down time varies according to the particular device, its mounting method and the ambient temperature. The typical cool-down time is roughly one minute.What are other uses of NTC ThermistorsNTCs are used for many other applications as well. Besides their usefulness in inrush current suppression, NTC thermistors' accurate temperature response, high stability and excellent reliability are well-suited to many other areas of electronic design. For example, they are often used in applications such as temperature measurement, temperature control, temperature compensation, voltage regulation, air-flow and liquid level sensing, and in creating time delay circuits.NTC thermistors for Inrush Current LimitingOne advantage of NTC thermistors over active circuits for inrush current suppression is lower component costs. inrush current limiters are typically less expensive than active circuit components. However, the exact cost of each component depends on the power level of the power supply for which it is intended. Typically, the higher the power level, the larger and more costly the component The cost advantage of inrush current limiters over active circuits can be easily illustrated with the following example based on a 300W power supply. To provide inrush surge protection with inrush current limiters, the only components needed are two inrush current limiters, at a total cost of $.80 or less for both thermistors.A second inrush current limiter advantage is a simpler design. Because inrush current limiter-based surge suppression circuits designs typically involve fewer components, they are less complex than those involving active circuits. In turn, a simpler design reduces the time needed to design the inrush current suppression capability of the power supply. As a general rule of thumb, using inrush current limiters for inrush current suppression requires only about one-fifth the time needed to design a comparable active circuit.Also, the inrush current limiter design provides greater manufacturing simplicity and lower reject rates. Fewer components means fewer assembly steps. A lower component count also decreases the potential for manufacturing rejects as a result of defective components.inrush current limiter-based surge suppression designs typically require significantly less space on the power supply circuit board than active circuits. For applications where the space available is at a premium, this can be a critical consideration.The failure mode when using an active circuit with a resistor usually requires component replacement. However, inrush current limiter-based in- rush surge suppression is self-protecting in the failure mode, because their resistance drops as temperature increases.Active Circuits For Inrush CurrentAs mentioned previously, various types of "active" circuits are sometimes used as alternatives to NTC thermistors (inrush current limiters) for certain applications. These component alternatives include triacs, resistors, and thyristors.An active circuit alternative is a triac (typically priced at about $1.00 for a 300W power supply), plus a resistor (about $.60), plus the circuit needed to drive the triac ($.20 or more) for a total of $1.80.Despite the economic and design simplicity advantages inrush current limiters offer for inrush current suppression, there are some situations when an active circuit may provide a more appropriate solution. For example, active circuits can sometimes be a better choice than inrush current limiters when "hot restart" capabilities are critical. The advantage is related to the cool down/recovery time required for the resistance of the inrush current limiter to increase sufficiently to provide the required level of inrush current protection. If the power drops out for a period shorter than the specified recovery time, say, for a few seconds, the thermistor will not have an opportunity to cool down and return to its initial level of resistance. When the power comes back on, the resistance is too low to provide sufficient inrush protection, so circuits could be damaged, fuses blown, etc.Active circuits offer lower power dissipation than inrush current limiters at higher power ratings (typically those above 300W). Because these designs typically run much cooler than NTCs, their heat dissipation/heat sinking requirements are lessCombination of NTC Thermistors and Active CircuitsThere is a design technique engineers can employ to eliminate the problems posed by the cool-down/recovery time required for inrush current limiters to return to their initial level of resistance. Essentially, this involves designing inrush current protection to drop the inrush current limiters out of the circuit after they have performed their function. By removing them from the circuit once the initial surge has passed, the thermistors have an opportunity to cool down, so they are ready to respond to a subsequent surge after a power drop-out occurs.This technique requires the addition of either a relay or a triac in parallel with the inrush current limiter, plus the circuits necessary to control it. All the components of the protection circuit would be in series with the input to the line. Once the inrush current has been absorbed by the thermistor, then either the triac starts firing or the relay closes. The simplest method of powering these components is from the power supply itself. Once the power supply starts, it closes the relay or fires the triac, dropping the thermistor out of the circuit and allowing it to cool down and regain its initial resistance, so it's ready to provide inrush current protection.ocete jos?

U ruralnim krajevima na ovakve postove kazu: "j**a ti mene?". Ne znam kako to kod vas u gradu kazu?

[stein]

Nisam ja to za tebe spremio. To je za Miku... http://www.diyaudio.rs/index.php?/topic/165-soft-start/page__view__findpost__p__4529 i za one koji se mogu zaneti kada prave pojačalo koje ne pravi problema sa prelaznim pojavama kod uključenja, uostalom kako i piše u tekstu, za potrošače od 300W pa naviše, preporučeno i t d...