I scavenge an old CRT monitor, and saw some transistor which i'm thinking to reuse, so my question :
CAN I use transistor of other type (video) to use as audio or other application like power switching/regulation ? My example here is :
C5404 from Toshiba, the datasheet is as follow : http://pdf.chinaicmart.com/88888/20083794333540.pdf
This is use for high speed switching application in TV, is it possible to make it into power shutoff or soft starting transistor ? or even for audio amplification usage also no problem ?
CAN I use transistor of other type (video) to use as audio or other application like power switching/regulation ? My example here is :
C5404 from Toshiba, the datasheet is as follow : http://pdf.chinaicmart.com/88888/20083794333540.pdf
This is use for high speed switching application in TV, is it possible to make it into power shutoff or soft starting transistor ? or even for audio amplification usage also no problem ?
The 2SC5404 is a line output transistor or horizontal output as sometimes called. These types were common in the days of CRT TV's , types like BU208, BU508 S2000AF BUT11 etc etc.
Generally these are not suited to linear audio amps as the main problem is that the gain is low. They are really intended to be driven either fully on or fully off. That said they are just silicon NPN devices, it's just that the properties are optimised for switching.
Small signal transistors and video output transistors are often overlooked for audio and they can be an excellent choice in some applications having low junction capacitance and good HF characteristics.
Generally these are not suited to linear audio amps as the main problem is that the gain is low. They are really intended to be driven either fully on or fully off. That said they are just silicon NPN devices, it's just that the properties are optimised for switching.
Small signal transistors and video output transistors are often overlooked for audio and they can be an excellent choice in some applications having low junction capacitance and good HF characteristics.
guess we cannot use it as audio amplification..... NVM
then is it a good choice to use it only for switching purpose of my amplifier ?
Such as soft starting and for safety tripping (over current tripping protection) ? since they are excellent in FAST switching
then is it a good choice to use it only for switching purpose of my amplifier ?
Such as soft starting and for safety tripping (over current tripping protection) ? since they are excellent in FAST switching
You would have to determine its suitability making sure that on start up the devices' SOAR (safe operating area) was not compromised.
haha, then guess transistor scavenged is hard to apply for audio and power unit : (
except we scavenge from other audio unit.(amplifier)
except we scavenge from other audio unit.(amplifier)
It's not that hard if you know what you are doing.All transistors work basicly in the same way.You need only the datasheet to see the specs and some knowlege about it.
haha, yeah, just same npn and pnp, but they have specified function/special, which they do good in them. I also agree with you, if you have knowledge and some spec, it is not too difficult to find a suitable application to use it.
Leon, you have any article/tutorial about how to utilise transistor or how to fully understand the specification ? (having problem understand them) in order to do those jobs ?
Leon, you have any article/tutorial about how to utilise transistor or how to fully understand the specification ? (having problem understand them) in order to do those jobs ?
This is has become a bit of a classic, if you can get hold of a copy. Library maybe ?
The Art of Electronics - Wikipedia, the free encyclopedia
I'm afraid a lot of knowledge is hard won through study and experience and in my case it being the day job for many years... if there is anything in particular you want help with or don't understand then maybe we can help 🙂
The Art of Electronics - Wikipedia, the free encyclopedia
I'm afraid a lot of knowledge is hard won through study and experience and in my case it being the day job for many years... if there is anything in particular you want help with or don't understand then maybe we can help 🙂
hahha, yeah ! Unlike IC, transistor datasheet doesn't provide application mode circuit (well...... understandable) and the transistor gain is variable (in a range), so the first thing is that i dunno how to SET the transistor's gain in a circuit. (been longing to learn that)
I also saw some article about how to make an switching device with transistor (act like relay), but can't fully understand its operation.
Also about the operation and example of an transistor work as high speed switching (well... over current protection, etc) as a protective member (maybe more useful in audio amp)
I also saw some article about how to make an switching device with transistor (act like relay), but can't fully understand its operation.
Also about the operation and example of an transistor work as high speed switching (well... over current protection, etc) as a protective member (maybe more useful in audio amp)
OK... so you need to do a lot of reading up 🙂
"How to set the transistors gain in a circuit ?" You can't and you don't...
A given transistor has a gain spread when manufactured. The best of the bunch might be say 200 and the worst 60. It's the circuit designers job to ensure that the circuit will work just as well with any gain value for that device.
As far as amplifiers go it's the value of the other components that set the gain of the finished amplifier. That little trick is done by negative feedback mostly, and that ensure all the amplifiers of a particular design all finish up with exactly the same gain irrespective of whether all the transistors have a high or low gain or any combination.
High speed switching is a subject on it's own... a transistor used as a switch (like in a TV line output stage) has to be driven correctly to minimise operation in the linear part of its characteristic. And the secret of that is in the drive waveform...
Library... books 😉
argh...... its tons of books in library, time to dig them are essential i think.
Hope i won't get drown in the book "waves" ....
Hope i won't get drown in the book "waves" ....
There are many books , but some of them explane it overcomplicated wich results in that some people get it wrong.Here for instance some people believe that transistors work like a switch, if you give voltage to basis than i's on and otherwise its off.
This is not true, they work like a valve, I mean mechanical valve for water.If you turn it then the waterflow is more or less.This means that you can control the amount of water wich is flowing through it.
Exactly like this also a transistor works. You can control the current wich is going through it by the voltage at the base.If you apply higher voltage to the base then it will conduct more current.
The only difference between switching and audio transistors is that audio transistors do it more linear wich means that you can control the current more precisely.
This is not true, they work like a valve, I mean mechanical valve for water.If you turn it then the waterflow is more or less.This means that you can control the amount of water wich is flowing through it.
Exactly like this also a transistor works. You can control the current wich is going through it by the voltage at the base.If you apply higher voltage to the base then it will conduct more current.
The only difference between switching and audio transistors is that audio transistors do it more linear wich means that you can control the current more precisely.
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