Tutorial: How to design a transistor circuit that controls low-power devices

I describe how to design a simple transistor circuit that will allow microcontrollers or other small signal sources to control low-power actuators such as solenoid valves, motors, etc.

Category:

Science & Technology

Tags:

• DIY
• howto
• transistor
• design
• circuit
• electronics
• microcontroller
• pn2222a

[directcurrent10]

what course should i take in college to learn that kind of works.! co'z that is my hobbies..~ ! its electrical engineer or electronics engineer???? tell me pls i'm curious.!

[bkraz333]

@directcurrent10 If you take electrical engineering courses in college, you will probably learn a fair bit about transistors. If you study on your own, visit a hackerspace, read books, find a mentor, you will probably learn a lot more. Good luck!

[cmxcmx]

Very interesting. I'm happy I subscribed to your channel :)

It's been a long time since I did anything with electronics (and that was only very basic stuff) and I'm thinking of getting back into it a bit more seriously. I like that you take the time to explain some of the practical issues instead of "just theory" - though theory is appreciated; I have a hard time internalizing equations.

[bkraz333]

@cmxcmx Great! Welcome to the hobby. Let me know if you are interested in hearing about any topic in particular. There are probably many other people with similar questions.

[superdau]

The voltage drop of a junctions is highly current (and temperature) dependent. So if you talk about 0,6V it's for very low currents, where a diode is just starting to conduct. The higher the current the larger the drop. A standard 1N4007 diode has almost 1V drop at 1A. It's similar for a Base-Emitter-junction.

Keep that in mind when dealing with high power transistors. Their V_BE can quite above 1V at high base currents. (and V_CE will be way higher than 0,1V, too; more like 1-2V)

[bkraz333]

@superdau Thanks!

[directcurrent10]

@bkraz333 that is a website??

[karachiluvrs21]

I have done electronic engg but i don't know how to design electronic circuit but i have good knowledge about devices used for designing.Can you tell me how can I learn to design circuits???

[MrJaffaMicroBrain]

Really good tutorial. I salute you sir and hope that you can produce and share more.

[CYBERlite2010]

Finally, a way to control a motor requiring 12 V from an Arduino and L293D. :)

[madamerotten]

Sure they make 4300 Ohm resistors. That's a standard +/-5% value in the EIA E24 series.

[icegate2901]

The shining mon can not make it clerer, If any one can, Mr Easter can can

[ChuffChuffWoo]

Very good video! I'd probably have used a 2k2 in the base leg to provide plenty of headroom - depends how much current loading the driving signal cam provide, I often drive transistors off CMOS logic or LM339s and LM324s

[ggattsr]

You have a gift for making complex topics very easy to understand. Thanks for sharing your gift with those of us with a never ending passion for all things electronic. Great website also. I just subscribed to your channel.