Hahaha..I just did this and my scope picked it rt up, I adjusted the variable resistor and it smoothed rt out. I showed my son how brilliant I am then he saw my phone and the video. Lol .. now I've got to learn how to use my scope. It says 200mhz. It's pretty old scope but it's a beauty. CRT is brilliant. Thx for the video
There's something missing from the circuit diagram, and I figure I should mention it just in case: you really want to have a flyback diode over the motor, as it's an inductive load, and without one, you could end up with a spike that would fry the other components when the motor spins down, causing the magnetic field to collapse and its energy to discharge. The flyback diode gives an alternative route for the current back through the motor, so it doesn't go back into the 555, &c.
Was thinking, to further reduce the cost of the BOM ... that TO-220 Mosfet may be the most expensive thang. Can be replaced by a logic level AO3400 or such, if you want to fiddle with surface mount. Maybe add room for optional pull-down and zener clamp on that gate. If you go with dueling surface mount options on your next PCB, the ne555dr is only about 1.5 cent: www.aliexpress.com/item/32920662510.html
The other good thing about the 555, is that the output(pin 3) is push-pull, and can source or sink 200 mA. That means, with an appropriate resistor, it can directly drive the base of a transistor, or the gate of a MOSFET. No beta multiplier, no pull up resistor necessary! for loads under 200 mA, it can directly drive a light load.
1n4001 diodes are standard recovery power diodes. the problem with these diodes, is that when they are reverse biased, there is a tail current before the diode quits conducting, an effect similar to a capacitor in parallel with it. I would suggest switching diodes, like 1N4148. another thing to try, would be schottky diodes, like 1N5819, which have much less forward voltage drop. The switching diodes have a negligible current tail, and the schottky doesn't have ANY current tail, though, it does have about 100 pico farads of junction capacitance. This video makes me want to get a 555 timer, and play with it again. I haven't touched one in almost 20 years!
This is a great channel :) Such an accessible way to explain electronics - gives a real fundamental explanation for basic circuits - exactly what is needed!
Frequency range is very small due to 1k resistor, changing which does change duty cycle along with frequency. I tried one 555 to generate pulse and other in mono-stable for duty cycle. But both need to be calibrated. In the end I used TL494 IC, it is also simple and allows changing duty cycle by controlling voltage.
A nice circuit can be made with the addition of LM311 comparator, giving 0-100% duty cycle range and very stable signal. Frequency is adjusted at capacitor, and a second 555 is used as a buffer to amplify signal.
the frequency doesn't actually change. It's just the proportion between on and off time that's changing. It actually stays around 500Hz and if its completly on it changes because of the frequency detection of the oscilloscope is irritated.
Thank you for this. I’m pretty new to circuits and have been using microcontrollers for pwm. I have read about using 555 timers but like you said, looks kind of daunting when you are new. The biggest reason I want to get away from the microcontroller is the boot up time. If I want to use a dimmer for example it’s not instantly on unless the mc is already powered. I have also read about another chip that is designed specifically for this: ltc6992, though it seems to be sold out everywhere. It’s more expensive but simpler. Once the chip shortage is over you should make a video with it :)
@@SimpleElectronics 6 months later 8.5K subs. Well done. I like this level of tutorial. Only thing I would like to see different is a little more explanation of how the circuit works.
@@SimpleElectronics Ha Ha, sorry I just realised I was looking at views not subs. 3K to 6K though is not bad. you've still doubled it in 6 months. I'm still struggling to reach 1K :-(
The frequency change can be avoided if you use a constant current regime for charging / discharging of the capacitor. I have developed a special circuit design for a voltage controlled PWM generator based on a TLC556 (2 timers in 1 device). This circuit uses only two additional components, a constant current diode E-101 (0.1 mA, min voltage drop
'Thank GOD'🙏🏾 and thank you very much for sharing your support and time 😉 Your video presentation was REALLY good 😁I'd like to know 🙄 how I can purchase your 12vdc module 😉 Let me know 🤔I look forward to hearing from you
Are you aware of that most of your idle power is wasted in the 1k resistor? You can reduce your idle power loss by more than an order of magnitude when you use the TLC555 and you control the duty cycle with your diode / pot arrangement from the output pin 3 of the timer IC.
Have you checked the output of your power supply with the scope? I ask because the Jitter of some of the wave forms seen could be coming from the power supply. Using batteries or Linear would be best. Buck or Boost convertor power supplies cause Jitter.
This is very true! I however wanted to test this in a likely situation - which means typically, a switching power supply (whether it be a wall-wart or bench top supply)
I made the same circuit on tinkercad( online simulator), I am getting a wave on oscilloscope but when rotating the potentiometer the graph the wave is not change, it remains the same. Could you please tell me why this is happening? Please reply its urgent.
The frequency will change if the values are different - i think the caps can be any non-polarized type. This is the cool thing about electronics, you can build it and see what happens!
@@SimpleElectronics thank you for your reply! I'm just getting into electronics. So far any circuit I try to recreate - does not work at all. I'll try this with different value caps I was able to scavenge and I'll try to make sure one of them is 10 times less capacity than the other and see what happens.
Good information! I am curious to know if yours had a audible frequency sound? Mine has a low frequency buzz sound and so I was wondering if that is normal, it does work great though. Thanks
I was wondering how does the duty cycle can be changed not by knob (i.e. potentiomter) but by those system that has push buttons. How does the push buttons change the value of applied voltage? One push button increase and the other push button decrease the voltage.
Sir do you know how can I control pick up coils out put for distributors? I need some thing to control duration of pulses ore the 4 pin gm ignition module Im experimenting lot with engines so I wuld like to build me self variabel controled ignition timing . Im simply useing multipel engine types so I need some thing that does that task . Im even useing dual coils and dual 4 pin gm ignition modules only problem I have only 1 pick up coil so I need to ajust that for ich coil corectly.
you know....I'm nut sure what a zener diode would do...the goal of the diodes in this circuit is to direct the charge/discharge through different sides of the voltage divider (potentiometer). I think you should try it! It could end up being interesting!
I'm iffy on the variable duty diodes coupling since what you're showing is not the way they show in datasheets. You have an error with your scales with reference to the .1 uf equalling 10 nf. Yes 104 is 10 nf but 10nf equals 0.01uf not 0.1uf. WHERE IS THE PWM demo?
That is a D3806, and if you don't have one, you should! it's a great unit! rover.ebay.com/rover/1/711-53200-19255-0/1?mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2FD3806-CNC-DC-Constant-Current-Power-Supply-Step-Down-Module-Voltage-Ammeter%2F274260954105%3Fhash%3Ditem3fdb3a0bf9%3Ag%3AjdwAAOSwl5VbD-1m&campid=5338675657&toolid=10001&customid=d3806
You seem overly concerned about the cost of things that are all pretty cheap to begin with. ALL these parts can be scavenged for free from many simple devices. Also repeatedly calling this extremely simple project daunting and scary tells people you don't think they are very smart, and only serves to discourage them from doing the project at all. I would suggest referring to a printed wiring diagram instead of a hand drawn one. Then, they can see what you changed. The volume and focus of the video were good, as was your narration. Good pacing and well explained.
Hahaha..I just did this and my scope picked it rt up, I adjusted the variable resistor and it smoothed rt out. I showed my son how brilliant I am then he saw my phone and the video. Lol .. now I've got to learn how to use my scope. It says 200mhz. It's pretty old scope but it's a beauty. CRT is brilliant. Thx for the video
There's something missing from the circuit diagram, and I figure I should mention it just in case: you really want to have a flyback diode over the motor, as it's an inductive load, and without one, you could end up with a spike that would fry the other components when the motor spins down, causing the magnetic field to collapse and its energy to discharge. The flyback diode gives an alternative route for the current back through the motor, so it doesn't go back into the 555, &c.
This is what you were talking about!! This is alot cheaper and simpler then a NANO!! Dang now I gotta order a bunch of these
That would be the one, sir! when it becomes miniaturized, it will be tiny and very useful!
Was thinking, to further reduce the cost of the BOM ... that TO-220 Mosfet may be the most expensive thang.
Can be replaced by a logic level AO3400 or such, if you want to fiddle with surface mount. Maybe add room for optional pull-down and zener clamp on that gate. If you go with dueling surface mount options on your next PCB, the ne555dr is only about 1.5 cent:
www.aliexpress.com/item/32920662510.html
The other good thing about the 555, is that the output(pin 3) is push-pull, and can source or sink 200 mA. That means, with an appropriate resistor, it can directly drive the base of a transistor, or the gate of a MOSFET. No beta multiplier, no pull up resistor necessary! for loads under 200 mA, it can directly drive a light load.
1n4001 diodes are standard recovery power diodes. the problem with these diodes, is that when they are reverse biased, there is a tail current before the diode quits conducting, an effect similar to a capacitor in parallel with it. I would suggest switching diodes, like 1N4148. another thing to try, would be schottky diodes, like 1N5819, which have much less forward voltage drop. The switching diodes have a negligible current tail, and the schottky doesn't have ANY current tail, though, it does have about 100 pico farads of junction capacitance. This video makes me want to get a 555 timer, and play with it again. I haven't touched one in almost 20 years!
Great tips! definitely wanted to make it with what I had and now I want to explore different diodes!
Nice explanation.liked the way you tested the variation in output using different components.keep up👍
This is a great channel :) Such an accessible way to explain electronics - gives a real fundamental explanation for basic circuits - exactly what is needed!
Frequency range is very small due to 1k resistor, changing which does change duty cycle along with frequency.
I tried one 555 to generate pulse and other in mono-stable for duty cycle. But both need to be calibrated.
In the end I used TL494 IC, it is also simple and allows changing duty cycle by controlling voltage.
A nice circuit can be made with the addition of LM311 comparator, giving 0-100% duty cycle range and very stable signal. Frequency is adjusted at capacitor, and a second 555 is used as a buffer to amplify signal.
the frequency doesn't actually change. It's just the proportion between on and off time that's changing. It actually stays around 500Hz and if its completly on it changes because of the frequency detection of the oscilloscope is irritated.
Thank you for this. I’m pretty new to circuits and have been using microcontrollers for pwm. I have read about using 555 timers but like you said, looks kind of daunting when you are new. The biggest reason I want to get away from the microcontroller is the boot up time. If I want to use a dimmer for example it’s not instantly on unless the mc is already powered.
I have also read about another chip that is designed specifically for this: ltc6992, though it seems to be sold out everywhere. It’s more expensive but simpler. Once the chip shortage is over you should make a video with it :)
Shocked when only seeing 3K subs. Very well done video
That's very kind of you, thanks! I'm glad you like the videos!
@@SimpleElectronics 6 months later 8.5K subs. Well done. I like this level of tutorial. Only thing I would like to see different is a little more explanation of how the circuit works.
@@SteveRaynerMakes 8.5k? I wish :) I'm at 6k
@@SimpleElectronics Ha Ha, sorry I just realised I was looking at views not subs. 3K to 6K though is not bad. you've still doubled it in 6 months. I'm still struggling to reach 1K :-(
@@SteveRaynerMakes it will come! I've been at it for 4 years, keep it up!
This is a good demonstration. Thank you for sharing it.
The frequency change can be avoided if you use a constant current regime for charging / discharging of the capacitor. I have developed a special circuit design for a voltage controlled PWM generator based on a TLC556 (2 timers in 1 device). This circuit uses only two additional components, a constant current diode E-101 (0.1 mA, min voltage drop
Note. If you are using the 5% or 10% tolorance resistors, then 220 ohms will be red, red, brown, silver or gold.
Very interesting, I'll have a go at this. Thank you.
Nice tutorial.
'Thank GOD'🙏🏾 and thank you very much for sharing your support and time 😉 Your video presentation was REALLY good 😁I'd like to know 🙄 how I can purchase your 12vdc module 😉 Let me know 🤔I look forward to hearing from you
Hello, thanks so much for watching! I don't sell the kits, but hopefully you have learned enough to make one yourself!
Very good video, subscribed.
Nice job.
Are you aware of that most of your idle power is wasted in the 1k resistor? You can reduce your idle power loss by more than an order of magnitude when you use the TLC555 and you control the duty cycle with your diode / pot arrangement from the output pin 3 of the timer IC.
How can you make a VOLTAGE-controlled PWM rom a 555?
GREAT VIDEO!!!
Have you checked the output of your power supply with the scope? I ask because the Jitter of some of the wave forms seen could be coming from the power supply. Using batteries or Linear would be best. Buck or Boost convertor power supplies cause Jitter.
This is very true! I however wanted to test this in a likely situation - which means typically, a switching power supply (whether it be a wall-wart or bench top supply)
Hello, is there a way to slow down a micro motor that is 1.5v at 8000rpm to 300rpm? Please advise.
Very good !
Thank you, I'm glad you liked it!
Hi, Is that a 0 to +12v pp i.e. all in the positive domain? Or is it -6v to +6v pp, i.e. half negative and half positive? Thanks for the video.
all positive!
I made the same circuit on tinkercad( online simulator), I am getting a wave on oscilloscope but when rotating the potentiometer the graph the wave is not change, it remains the same. Could you please tell me why this is happening?
Please reply its urgent.
I would recommend double-checking your connections because it works perfectly for me!
i'm late but you may wanna introduce noise
does it have to be ceramic capacitors? and those exact values? what if they're different?
The frequency will change if the values are different - i think the caps can be any non-polarized type. This is the cool thing about electronics, you can build it and see what happens!
@@SimpleElectronics thank you for your reply! I'm just getting into electronics. So far any circuit I try to recreate - does not work at all. I'll try this with different value caps I was able to scavenge and I'll try to make sure one of them is 10 times less capacity than the other and see what happens.
Good information! I am curious to know if yours had a audible frequency sound? Mine has a low frequency buzz sound and so I was wondering if that is normal, it does work great though. Thanks
mine does not! Apparently some ceramic capacitors do that though!
can be applied in vape electric cigarettes
Nice video, can I use this circuit to control servo motor?
No you can't unfortunately, but there are servo circuits for the 555 timer
you are great thaaaank you
Thanks!
I was wondering how does the duty cycle can be changed not by knob (i.e. potentiomter) but by those system that has push buttons. How does the push buttons change the value of applied voltage? One push button increase and the other push button decrease the voltage.
Not likely done with a 555 timer, more than likely done via a microcontroller
Sir do you know how can I control pick up coils out put for distributors?
I need some thing to control duration of pulses ore the 4 pin gm ignition module Im experimenting lot with engines so I wuld like to build me self variabel controled ignition timing .
Im simply useing multipel engine types so I need some thing that does that task .
Im even useing dual coils and dual 4 pin gm ignition modules only problem I have only 1 pick up coil so I need to ajust that for ich coil corectly.
Can I use zener diode
you know....I'm nut sure what a zener diode would do...the goal of the diodes in this circuit is to direct the charge/discharge through different sides of the voltage divider (potentiometer). I think you should try it! It could end up being interesting!
@@SimpleElectronics it worked fine for me
i would love to controle somthing like this with a digital pin frome a arduino but am having trouble finding a way to do it.
My friend Gadget Reboot used a digital potentiometer IC controlled via i2c to modulate a 555....check it out! th-cam.com/video/oFtGOOA25tA/w-d-xo.html
@@SimpleElectronics ahh ill go look i was wondering how i would controle restance without a pot. thanks a heap
Leave him a comment letting him know I sent you if it isn't a bother please!
can i use different capacitor values?
yes! with differing results though! experiment!
Alright thanks
6:25 --he says they go to pin 6 (incorrect) but connects to pin 7 (correct).
How to use it with 10k potenciometr
I got a much narrower range of duty cycles with pretty much the same components, why could that be?
do you have the non-cmos version of the 555?
@@SimpleElectronics Yes
That is likely your problem! The bi-polar version is less efficient than the cmos
@@SimpleElectronics how can you tell a bi-polar from cmos ? and counterfeit from original
I'm iffy on the variable duty diodes coupling since what you're showing is not the way they show in datasheets. You have an error with your scales with reference to the .1 uf equalling 10 nf. Yes 104 is 10 nf but 10nf equals 0.01uf not 0.1uf. WHERE IS THE PWM demo?
Nice video, thank you! What is that power supply, looks cool :)
That is a D3806, and if you don't have one, you should! it's a great unit! rover.ebay.com/rover/1/711-53200-19255-0/1?mpre=https%3A%2F%2Fwww.ebay.com%2Fitm%2FD3806-CNC-DC-Constant-Current-Power-Supply-Step-Down-Module-Voltage-Ammeter%2F274260954105%3Fhash%3Ditem3fdb3a0bf9%3Ag%3AjdwAAOSwl5VbD-1m&campid=5338675657&toolid=10001&customid=d3806
@@SimpleElectronics Ah thank you! Got one on its way now :)
You seem overly concerned about the cost of things that are all pretty cheap to begin with. ALL these parts can be scavenged for free from many simple devices. Also repeatedly calling this extremely simple project daunting and scary tells people you don't think they are very smart, and only serves to discourage them from doing the project at all. I would suggest referring to a printed wiring diagram instead of a hand drawn one. Then, they can see what you changed. The volume and focus of the video were good, as was your narration. Good pacing and well explained.
.1uF = 100nF. " F.00m.00u.00n.00p"
F-arad
m-illiFared
u-microFared
n-anoFared
p-icoFared