Great videos, thank you for these! It's probably important to point out that mysterious antiparallel diode across the emitter and collector (highlighted @7:00 in this video) is *I think* only good for suppressing flyback from H-bridge arrangements, and /not/ simple switching of a single inductor. For switching in the case shown for e.g. a TIP125 (PNP), with inductive load between collector and ground, a proper suppression diode would be reverse biased between collector and ground, whereas TIP125 internal suppression diode is reverse biased between the collector and /positive supply/, which doesn't address at all the large negative-going spike back from the inductor when the transistor turns off. In my application I am running a 12V buzzer at 60Hz generated by the TIP125, and found huge 150V spikes below ground at the collector on each on-to-off transition. Adding an external reverse biased diode between the collector and ground was essential: it suppressed the spike completely. Diagram of this situation, with scope pics + schematic shown here: seriss.com/people/erco/tmp/tip125-with-vs-without-added-protection-diode.jpg
I should add I had thought the diode within the TIP125 was handling spike suppression for me, but it wasn't until a friend peer-reviewed my schematic and caught that the TIP125's internal diode was going the wrong way for suppressing the inductive load (and connected to the wrong supply line, positive instead of gnd). After realizing he was right, double checked with a scope, and sure enough, huge spikes of over 10x the supply current at the collector, even though the TIP125 was working OK (probably by luck!) and the buzzer was buzzing. But when I added the extra suppression diode, the buzzer sounded a bit louder and clearer, as I suppose without the extra diode, the inductor remained energized longer, decreasing the volume of the buzzer.
Lewis, as always, great stuff. Starting at 1:29 things went a little confusing. For me, (for example in the case of the npn darlington), the fog lifted when it became clear that you, (I presume), were striving to keep the base-emitter voltage below 5V, (with the transistor emitter tied to ground). ... Because the Arduino is also tied to the same ground and the Arduino was interacting with the transistor base, so had to be less than 5V. Similarly for the pnp darlington. It would be nice if you could confirm, Lewis. Feedback: The two items at diagram at 2:54 should change places due to referral to previous diagram! Finally: Really useful info from 12:13 onward and wow! very useful at 14:43 onward. Thanks & Best Regards Lewis!
Thanks Lewis, your explanations are perfectly clear! It's an interesting subject when you have to interface loads from an Arduino. This video was very useful for me.
Your current arrows show electron flow, not current: "Conventional Current assumes that current flows out of the positive terminal, through the circuit and into the negative terminal of the source. This was the convention chosen during the discovery of electricity."
I'm aware of this and changed it in later videos. In fact, electrons are the only charges that actually move. Positive flow has been proven wrong with the discovery of the electron that came later. Yes, they stayed with the conventional flow anyway. I worked for years with vacuum tubes, etc.; that is how it was taught in the military.
Links: Using the ULN2003A Transistor Array with Arduino Using the ULN2003A Transistor Array with Arduino www.bristolwatch.com/ele/uln2003a.htm ULN2003A Darlington Transistor Array with Circuit Examples ----- Using the TIP120 & TIP120 Darlington Transistors with Arduino Using the TIP120 & TIP120 Darlington Transistors with Arduino www.bristolwatch.com/ele/tr3.htm Tutorial Using TIP120 and TIP125 Power Darlington Transistors ----- Using Power MOSFETS with Arduino Using Power MOSFETS with Arduino www.bristolwatch.com/ele/tr2.htm N-Channel Power MOSFET Switching Tutorial www.bristolwatch.com/ele/tr1.htm P-Channel Power MOSFET Switch Tutorial ----- Using PNP Bipolar Transistors with Arduino, PIC Using PNP Bipolar Transistors with Arduino, PIC Using NPN Biploar Transistors with Arduino, PIC Using NPN Biploar Transistors with Arduino, PIC www.bristolwatch.com/ele/tr4.htm Understanding Bipolar Transistor Switches ----- How to build a Transistor H-Bridge for Arduino, PIC How to build a Transistor H-Bridge for Arduino, PIC www.bristolwatch.com/ele/tr5.htm Build a High Power Transistor H-Bridge Motor Control www.bristolwatch.com/ele/tr6.htm Driving 2N3055-MJ2955 Power Transistors with Darlington Transistors ----- Build a Power MOSFET H-Bridge for Arduino, PIC Build a Power MOSFET H-Bridge for Arduino, PIC www.bristolwatch.com/ele/h_bridge.htm H-Bridge Motor Control with Power MOSFETS www.bristolwatch.com/ele/tr7.htm More Power MOSFET H-Bridge Circuit Examples
So easy to understand... I am planning to use this on 12v motor with 4A stall current. So, is it save to use this transistor without heatsink? Regarding to the datasheet, the transistor can give 5A max.
Thinking about current models. If you are talking about loads in the KW range, it's not at all unreasonable to expect students to deal with multiple current models. I think it's helpful. Anyone who can't get over this standard issue should stay in the mW world.
My design team is trying to impose a waveform, generated by an Arduino, on the current coming from the wall outlet. Could these be used to do that? We're mechanical engineers so we're really bad at this.
Thank you for your video. I saw other videos that tell me how to text transistors but... it was not working with the TIP 120! Whenever I was testing with the multi-meter like a diode I didn't get the same reading between CE or EC. Your video show ne the diode. THANK YOU!
HELLO THERE . THERES A TIP142 NPN TRANSISTOR IM TRYING TO USE IN MY ONE TRANSISTOR SOUND AMP . SO TELL ME WHERE IS THE EXIT IS IT AN EMITTER OR COLLECTOR ???
@@LewisLoflin OH OK WELL I HAVE SEEN TONS OF CIRCUITS WITH SUCH TRANSISTOR AND I ACTUALLY BUILD ONE RIGHT NOW WHILE IM TYPING IT TO YOU BUT THE SOUND IS NOT LOUD BUT GOOD QUALITY . HERE IS THE PICTURE OF ONE OF THOSE FAMOUS AMPS WITH TIP142 .......... ibb.co/tXnvsRP
Hi Lewis, thanks for the video. I was unable to source a TIP120 so I have 121 instead. Does this work in the same way as 120 in terms of positioning of the load?
Hi Lewis, I have a question for you. Can i use tip120 with a plc that has transistor outputs at 24vcd to controll a solenoid of 1amp that has an 24vdc source? Thank you
Hey Lewis.. while making a van de grafe generator, the voltage is 10kV, The current on discharge is few mA, and I would want to switch it at 10kHz frequency. how can I do switching this fast?
Not sure what you are asking. Without knowing how it's constructed i have no idea what you are asking. I know exactly what a Vande Grafe generator is but the designs I saw used vacuum tubes.
God video which makes the stuff understandable. But I'm going to raise a flag here. The 46 ohm resistor you calculate somewhere, would need to be very big, like 15 watts, and you don't say anything of it. I also hear you say magnetic load where i expected you to say inductive load.
Not to be argumentative @@LewisLoflin, but power ratings of associated components SHOULD be noted in a basic tutorial - especially when it comes to exceeding the ratings of commonly used devices. Someone trying this configuration with a 1/4 watt 46 ohm resistor is going to learn about power dissipation in a big hurry and not in a good way! Having said that, thanks for this video. It does cover the basic concept very well!
@@LewisLoflin I don't know now... I've been watching so many of your videos but this one is great, much better then some. Nice and slow, slow people need slow teachers :)
I love this guy he misses noting and is pure class at explaining things.👍
Great videos, thank you for these!
It's probably important to point out that mysterious antiparallel diode across the emitter and collector (highlighted @7:00 in this video) is *I think* only good for suppressing flyback from H-bridge arrangements, and /not/ simple switching of a single inductor.
For switching in the case shown for e.g. a TIP125 (PNP), with inductive load between collector and ground, a proper suppression diode would be reverse biased between collector and ground, whereas TIP125 internal suppression diode is reverse biased between the collector and /positive supply/, which doesn't address at all the large negative-going spike back from the inductor when the transistor turns off. In my application I am running a 12V buzzer at 60Hz generated by the TIP125, and found huge 150V spikes below ground at the collector on each on-to-off transition. Adding an external reverse biased diode between the collector and ground was essential: it suppressed the spike completely. Diagram of this situation, with scope pics + schematic shown here: seriss.com/people/erco/tmp/tip125-with-vs-without-added-protection-diode.jpg
I should add I had thought the diode within the TIP125 was handling spike suppression for me, but it wasn't until a friend peer-reviewed my schematic and caught that the TIP125's internal diode was going the wrong way for suppressing the inductive load (and connected to the wrong supply line, positive instead of gnd). After realizing he was right, double checked with a scope, and sure enough, huge spikes of over 10x the supply current at the collector, even though the TIP125 was working OK (probably by luck!) and the buzzer was buzzing. But when I added the extra suppression diode, the buzzer sounded a bit louder and clearer, as I suppose without the extra diode, the inductor remained energized longer, decreasing the volume of the buzzer.
Lewis, as always, great stuff. Starting at 1:29 things went a little confusing. For me, (for example in the case of the npn darlington), the fog lifted when it became clear that you, (I presume), were striving to keep the base-emitter voltage below 5V, (with the transistor emitter tied to ground). ... Because the Arduino is also tied to the same ground and the Arduino was interacting with the transistor base, so had to be less than 5V. Similarly for the pnp darlington.
It would be nice if you could confirm, Lewis.
Feedback: The two items at diagram at 2:54 should change places due to referral to previous diagram!
Finally: Really useful info from 12:13 onward and wow! very useful at 14:43 onward.
Thanks & Best Regards Lewis!
Lewis, thank you so much for your videos. This one is by far the best microcontroller based use of BJTs on TH-cam. Thanks again.
I like your videos, simple facts, nothing fancy, just like it should be. Please keep making them.
R2 in the MJ2955 circuit is burning 11.5W (half an amp through 46 ohms)!
Thanks Lewis, your explanations are perfectly clear! It's an interesting subject when you have to interface loads from an Arduino. This video was very useful for me.
Your current arrows show electron flow, not current:
"Conventional Current assumes that current flows out of the positive terminal, through the circuit and into the negative terminal of the source. This was the convention chosen during the discovery of electricity."
I'm aware of this and changed it in later videos. In fact, electrons are the only charges that actually move. Positive flow has been proven wrong with the discovery of the electron that came later. Yes, they stayed with the conventional flow anyway. I worked for years with vacuum tubes, etc.; that is how it was taught in the military.
@@LewisLoflin thank you for your kind reply :) and for your efforts for making these videos :)
So clear and understandable. Many thanks Sensi!
Links:
Using the ULN2003A Transistor Array with Arduino
Using the ULN2003A Transistor Array with Arduino
www.bristolwatch.com/ele/uln2003a.htm
ULN2003A Darlington Transistor Array with Circuit Examples
-----
Using the TIP120 & TIP120 Darlington Transistors with Arduino
Using the TIP120 & TIP120 Darlington Transistors with Arduino
www.bristolwatch.com/ele/tr3.htm
Tutorial Using TIP120 and TIP125 Power Darlington Transistors
-----
Using Power MOSFETS with Arduino
Using Power MOSFETS with Arduino
www.bristolwatch.com/ele/tr2.htm
N-Channel Power MOSFET Switching Tutorial
www.bristolwatch.com/ele/tr1.htm
P-Channel Power MOSFET Switch Tutorial
-----
Using PNP Bipolar Transistors with Arduino, PIC
Using PNP Bipolar Transistors with Arduino, PIC
Using NPN Biploar Transistors with Arduino, PIC
Using NPN Biploar Transistors with Arduino, PIC
www.bristolwatch.com/ele/tr4.htm
Understanding Bipolar Transistor Switches
-----
How to build a Transistor H-Bridge for Arduino, PIC
How to build a Transistor H-Bridge for Arduino, PIC
www.bristolwatch.com/ele/tr5.htm
Build a High Power Transistor H-Bridge Motor Control
www.bristolwatch.com/ele/tr6.htm
Driving 2N3055-MJ2955 Power Transistors with Darlington Transistors
-----
Build a Power MOSFET H-Bridge for Arduino, PIC
Build a Power MOSFET H-Bridge for Arduino, PIC
www.bristolwatch.com/ele/h_bridge.htm
H-Bridge Motor Control with Power MOSFETS
www.bristolwatch.com/ele/tr7.htm
More Power MOSFET H-Bridge Circuit Examples
So easy to understand...
I am planning to use this on 12v motor with 4A stall current. So, is it save to use this transistor without heatsink?
Regarding to the datasheet, the transistor can give 5A max.
Thinking about current models. If you are talking about loads in the KW range, it's not at all unreasonable to expect students to deal with multiple current models. I think it's helpful. Anyone who can't get over this standard issue should stay in the mW world.
Well,
actually the best way to go would be using power Mosfets.
and for higher voltage loads use optical isolators ( opto transistors etc.)
Thank you bud pretty amazing stuff ! how about using this setup as an amplifier final drive ?
Cool video. I would use opto-couplers on that 200V circuit but still a nice video.
My design team is trying to impose a waveform, generated by an Arduino, on the current coming from the wall outlet. Could these be used to do that? We're mechanical engineers so we're really bad at this.
thanks for the video,make it a joy to learn, is there an explaination on DIAC only?
+Damoo Premchand There is no diac in this circuit. Those are spike suppressor diodes internal to the transistors.
Also can I use TIP120 in a boost or buck converter instead of a mosfet?
great job lewis! great help!
First class explanation Thank you
Thank you for your video. I saw other videos that tell me how to text transistors but... it was not working with the TIP 120! Whenever I was testing with the multi-meter like a diode I didn't get the same reading between CE or EC. Your video show ne the diode. THANK YOU!
+Laboratório Aberto This is a Darlington transistor which means multiple junction plus some resistor are also built in.
Thank you!
Thanks for the vid Lewis. The youtube title is 120 and 120 should be 120 and 125?
Dingo Correct - how did I not see that. Thanks.
thanks alot Lewis this is very nice stuff. So if i send more than 5mA to the base of tip120 it will destroy it ?
Why would you want to? Put a 1K resistor in series.
HELLO THERE . THERES A TIP142 NPN TRANSISTOR IM TRYING TO USE IN MY ONE TRANSISTOR SOUND AMP . SO TELL ME WHERE IS THE EXIT IS IT AN EMITTER OR COLLECTOR ???
You can't use a TIP142 or any of these in a sound amp. The built in resistors and damper diode are for switching circuits.
@@LewisLoflin OH OK WELL I HAVE SEEN TONS OF CIRCUITS WITH SUCH TRANSISTOR AND I ACTUALLY BUILD ONE RIGHT NOW WHILE IM TYPING IT TO YOU BUT THE SOUND IS NOT LOUD BUT GOOD QUALITY . HERE IS THE PICTURE OF ONE OF THOSE FAMOUS AMPS WITH TIP142 .......... ibb.co/tXnvsRP
Hi Lewis, thanks for the video. I was unable to source a TIP120 so I have 121 instead. Does this work in the same way as 120 in terms of positioning of the load?
Yes it will but not has a different voltage rating.
Hi Lewis, I have a question for you.
Can i use tip120 with a plc that has transistor outputs at 24vcd to controll a solenoid of 1amp that has an 24vdc source? Thank you
+Arturo Armas No problem.
@lewis : How is the current flow negative to positive??
That is the actual current flow. I use the opposite (wrong one) today because that is the way college teaches it. I came through the military first.
Hey Lewis.. while making a van de grafe generator, the voltage is 10kV, The current on discharge is few mA, and I would want to switch it at 10kHz frequency. how can I do switching this fast?
Not sure what you are asking. Without knowing how it's constructed i have no idea what you are asking. I know exactly what a Vande Grafe generator is but the designs I saw used vacuum tubes.
I think you're looking for this forum.arduino.cc/index.php?topic=117425.0
Thank you Sir.
God video which makes the stuff understandable. But I'm going to raise a flag here. The 46 ohm resistor you calculate somewhere, would need to be very big, like 15 watts, and you don't say anything of it. I also hear you say magnetic load where i expected you to say inductive load.
Because this teaches basic electronics. 15 watts would be correct.
Not to be argumentative @@LewisLoflin, but power ratings of associated components SHOULD be noted in a basic tutorial - especially when it comes to exceeding the ratings of commonly used devices. Someone trying this configuration with a 1/4 watt 46 ohm resistor is going to learn about power dissipation in a big hurry and not in a good way! Having said that, thanks for this video. It does cover the basic concept very well!
Nice lecture thanks for sharing
Very knowledge full video thanks sir
thank you sir
Valeu ! muito bom
hello sir for 30VDC can i use TIP125?
Yes.
Lewis Loflin i want to dim 30 vdc using PWM for Led.
Works fine. I've used them for that. Use a dropping resistor with the LED.
That's cool. Great ...
TIP-121 IS THE SAME????
Same as the 120 but is 80V. Might be other differences.
very good explanation, thank you Lewis!!! a thumbs up and a sub from me!
Thank You Sir!
Your videos are immensely helpful but you need a little work on presentation.
Such as?
@@LewisLoflin Well I am not good at public speaking but I like to criticize others, it's much easier than working on my own stuff. :)
This is an older video. I'll do an update.
@@LewisLoflin I don't know now... I've been watching so many of your videos but this one is great, much better then some. Nice and slow, slow people need slow teachers :)