The Ice =7V/ 470 Ω = 14,9mA. Usually we take 1/10 for Ib (basecurrent). So R2 = (UR2= 9V-2V-0,7V)/1,49mA= 4228 Ω (or 4K3) would be the best choise in my opinion to get the transistor fully saturated.
I have a question The base current in your circuit is in microamps but the min forward current for the led should be in milliamp, how is your led glowing when there isn't enough current.
so the base is connected to the collector which is the positive side of the circuit. That is how NPN transistor work. So the base doesn't get connected to the negative/ emitter side. Does the base for the PNP type get connected to the emitter side then?
The physical switch is just used to apply a small current to the base of the transmitter to switch it.on. if I removed the physical switch, there would always be current going to the base so the transistor would always be on. Cheers, John
You're absolutely correct. The purpose of the video is to show how a transistor can be switched on and off. The LED is just there so that there is something visual to see.
Hi Richard - the idea of the circuit is to show that if you apply a small current to the Base of the transmitter, this then turns on the transmitter to allow current to flow from the Collector to the Emmiter. I take your point though. It might have been better to say that pressing the button allows current to flow through the transistor, rather than saying it switches on the transistor.
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Just a quick note to say thanks for taking the tine to do all these. Im not absolute beginner but still find your 'short' sessions useful
The Ice =7V/ 470 Ω = 14,9mA. Usually we take 1/10 for Ib (basecurrent). So R2 = (UR2= 9V-2V-0,7V)/1,49mA= 4228 Ω (or 4K3) would be the best choise in my opinion to get the transistor fully saturated.
Perfect and Simple, thank you!
Great idea to use the 2 LEDs to compare the control loop & the high current or "load" loop 🤓👍👍👍
Thanks for the positive feedback 👍
This is cb configuration right ?
I have a question
The base current in your circuit is in microamps but the min forward current for the led should be in milliamp, how is your led glowing when there isn't enough current.
so the base is connected to the collector which is the positive side of the circuit. That is how NPN transistor work. So the base doesn't get connected to the negative/ emitter side.
Does the base for the PNP type get connected to the emitter side then?
I did the same design but i used two resistors of the same ohm value but im confused why LED 1 is still brighter than LED 2?
it's possible to use this to amplify the current of a piezoelectric element?
Any video teaching how to choose transistor?
Isn't the 2nd led more dim because of the higher value resistor?
Yes, that's correct. I included it in the circuit to show that there is a very small current being applied to the base of the transistor.
can you please hellp me, which kind of transistor you used
BC547 BJT
what if I want the transistor to act as a switch for a different power source?
is just what i wanted for test my transistor. tnks
thank you for the info....
why you not put led in same switch vcc roll what main point of transis .on off should doing plug battery and unplug zzzz.
Can you please again tell which npn transistor?
Hi, I used a BC 549 B. Cheers, John
@@quickstartworkbook1532 Is BC 547 ok too?
@@jumbo999614 Give it a try.
You are using a physical switch, this does show the use of transistor as a switch as I am looking for transistor as a switch and your video.
The physical switch is just used to apply a small current to the base of the transmitter to switch it.on. if I removed the physical switch, there would always be current going to the base so the transistor would always be on. Cheers, John
I got an error before I even started this build: "Brain is not compatible - or there is not enough IQ available."
Any fix for this? 😂
What kind of error did you get?
Lol
Yes there is, start from the very basics THEN move to transistors
Great video........
You're very welcome. Thanks for subscribing and commenting on the video ... much appreciated !
What the point of this.. .?? I can just connect the without the transistor...
You're absolutely correct. The purpose of the video is to show how a transistor can be switched on and off. The LED is just there so that there is something visual to see.
Thank you anna
14.7k resistance… did not work… I used 470 ohm
Muito bom só faltou a tradução!
Learn the fucking English
this is dumb if the transistor is the switch then why do you need a mechanical switch to turn it on and off for
Hi Richard - the idea of the circuit is to show that if you apply a small current to the Base of the transmitter, this then turns on the transmitter to allow current to flow from the Collector to the Emmiter. I take your point though. It might have been better to say that pressing the button allows current to flow through the transistor, rather than saying it switches on the transistor.
@@quickstartworkbook1532 actual the voltage turns the transistor on and current flows from emitter to collector
@@richardstephens-fd8jc in an npn transistor the current flows from the Collector to the emitter, and from the emitter to the collector in a PNP.
@@quickstartworkbook1532 current flow is from negative to positive current is made up of electrons conventional is positive to negative
@@richardstephens-fd8jc electron flow vs conventional current flow.... well that's an interesting conversation in itself 🙂