See Also Post #38, BECAUSE L.Q.C. is totally correct.

 

I see the anti-Micro crowd is out!
@Jerry-Hat-Trick has the right idea.
Depends on how much the OP can/wants to put into it.
20watts is not that a high requirement?
In fact the way I see it, a small 8pin micro could do it together with a small motor driver, DRV8833, at least that would be my first approach.
The code would not really 'take years to learn' !

 

I hate "E-Notation" too !!!

I'm not really "Anti-Micro", I'm just not into learning new languages at ~67-years old,
and then keeping up with the latest toys and continual changes.
But, of course, some people obviously have a propensity for learning new languages, more power to them.

Jerry-Hat-Trick also made another observation,
about the quick Code learners not being able to grasp the Hardware aspects.
I've just been a very-part-time Electronics-Hobbyist for ~60-years,
completely self-taught, with zero formal-training,
and I can do better than these young Code-brainiacs ???

I'm of the opinion that anyone should have a good grasp of the hardware FIRST,
as in, basic Analog-Control Circuitry, Op-Amps, FETs, etc..

Life is strange, I guess that's a good thing.
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You may notice that I did not comment about the micro either. THAT is because the whole approach is running backwards. First the hardware because that is the challenging part, then the controls, after the hardware is actually working. There have been several good circuits presented, but so far only a guess at motor speed and torque requirements, which will certainly depend on how the butter churn is built and what sort of clearances and friction are present.

 

I hate "E-Notation" too !!!

I'm not really "Anti-Micro", I'm just not into learning new languages at ~67-years old,
and then keeping up with the latest toys and continual changes.
But, of course, some people obviously have a propensity for learning new languages, more power to them.

Jerry-Hat-Trick also made another observation,
about the quick Code learners not being able to grasp the Hardware aspects.
I've just been a very-part-time Electronics-Hobbyist for ~60-years,
completely self-taught, with zero formal-training,
and I can do better than these young Code-brainiacs ???

I'm of the opinion that anyone should have a good grasp of the hardware FIRST,
as in, basic Analog-Control Circuitry, Op-Amps, FETs, etc..

Life is strange, I guess that's a good thing.
.
.
.

At 80 years old I love to see a design that 'works' when the task get tough.
I am going to keep copy just in case a need comes up. Perhaps I will build it to drive a window wiper motor just for fun.

 

I created first basic circuit of my life and it take 3 hours to get it working
any inputs @LowQCab and @crutschow ? how can we make it to take higher current? or can we use npn transistors? etc.

just curious if we can use this driver board below:
https://www.electronicscomp.com/l29...n41Q4TCa2a5KtitFlUu-jf_rjrUEuqGkaAnLLEALw_wcB

 

The first step towards higher-Current is to get rid of the wimpy 9V-Battery.
You must start with a Power-Supply that can deliver anywhere from ~20% to ~200% more Current
than will ever be demanded by the Load.
And, since your Load is controlled by a Relay, the Relay must be rated for the Locked-Rotor-Amps that
the Motor will draw every time it starts or reverses direction, otherwise
the contacts inside the Relay will be destroyed very quickly.

A Relay is not a Semiconductor, it is a Mechanical-Device that wears-out after X-number of cycles.
Semiconductors normally never "wear-out",
but your specific design choices can cause them to overheat and fail.
HEAT is always the enemy of Semiconductors.

Discrete Transistors can certainly be used, but they tend to not have many of the built-in features
that are built-in to readily available integrated "Controllers",
such as the MOSFET Gate-Drivers that I chose to create a PWM Full-Bridge-Motor-Controller.

The features that they bring to the table are ( at least ) ...............

1)
"Logic-Level"-Inputs, with extremely simple drive requirements,
( 2.5-Volts, with built-in hysteresis ), ( built-in static protection ).

2)
Blazingly fast "Rail-to-Rail" switching with no worries about "shoot-though" blowing things up.

3)
Rated for ~30-Amps Peak-Current, and ~8-Amps Continuous-Current,
( extreme overkill is always good to have ).

4)
Built-in "Under-Voltage-Lock-Out", ( UVLO ), if the Power-Supply drops below ~9-Volts,
( because of possible Motor-overload, or a possible inadvertent short-circuit in the wiring )
This adds an extra layer of protection against accidental smoking of parts.

5)
Two TO-220-5 style Transistor-Packages replace ~8 to ~16 individual Components.
( I would use these just for the construction convenience, if for no other reason )

6)
Greatly facilitates using high-Frequency PWM Motor-Speed, and Reversing-Control,
with a simple to understand and implement format.

And all of these reasons are why I would recommend against using discreet Transistors,
( not to mention the reduction in the number of complex Math-Calculations required ).

Yeah-but, yeah-but, yeah-but, they cost ~$10.oo each !!!!, and I'll need 2 of them !!!
Well it all depends on whether You want to blow-stuff-up in an interesting learning experience,
or put together a very competent device
that has the potential to be better than You can buy at any price.

( I've blown-up a lot of stuff, it can be really expensive, or even embarrassing sometimes )
.
.
.

 

Certainly many relays will have a shorter life span than high quality semiconductor devices from a reliable manufacturer. But I have installations that have performed flawlessly for 50 years, and in many industrial machines there are panels full of relays that run perfectly for years. So the fear of relay failure is unfounded in this instance.

Of course, the very poorest quality relays from some poor quality producer will not last as long. So I would not consider any of the relays from unknown import sales organizations for the application.

Consider that in this butter churn application the relay will probably be operating perhaps 10 times a minute for possibly 30 minutes, at most, once daily. How long will that take to achieve 50,000 operations? and if it is properly sized for the motor current, the contacts will last much longer than that.

 

I created first basic circuit of my life and it take 3 hours to get it working
how can we make it to take higher current? or can we use npn transistors? etc.

just curious if we can use this driver board below:
https://www.electronicscomp.com/l29...n41Q4TCa2a5KtitFlUu-jf_rjrUEuqGkaAnLLEALw_wcB

First, I would look at using higher DCV , you may want to look at the LMD18200, or DRV8833 etc boards similar to the L298. it is rated for 3A.

 

The first step towards higher-Current is to get rid of the wimpy 9V-Battery.
You must start with a Power-Supply that can deliver anywhere from ~20% to ~200% more Current
than will ever be demanded by the Load.
And, since your Load is controlled by a Relay, the Relay must be rated for the Locked-Rotor-Amps that
the Motor will draw every time it starts or reverses direction, otherwise
the contacts inside the Relay will be destroyed very quickly.

A Relay is not a Semiconductor, it is a Mechanical-Device that wears-out after X-number of cycles.
Semiconductors normally never "wear-out",
but your specific design choices can cause them to overheat and fail.
HEAT is always the enemy of Semiconductors.

Discrete Transistors can certainly be used, but they tend to not have many of the built-in features
that are built-in to readily available integrated "Controllers",
such as the MOSFET Gate-Drivers that I chose to create a PWM Full-Bridge-Motor-Controller.

The features that they bring to the table are ( at least ) ...............

1)
"Logic-Level"-Inputs, with extremely simple drive requirements,
( 2.5-Volts, with built-in hysteresis ), ( built-in static protection ).

2)
Blazingly fast "Rail-to-Rail" switching with no worries about "shoot-though" blowing things up.

3)
Rated for ~30-Amps Peak-Current, and ~8-Amps Continuous-Current,
( extreme overkill is always good to have ).

4)
Built-in "Under-Voltage-Lock-Out", ( UVLO ), if the Power-Supply drops below ~9-Volts,
( because of possible Motor-overload, or a possible inadvertent short-circuit in the wiring )
This adds an extra layer of protection against accidental smoking of parts.

5)
Two TO-220-5 style Transistor-Packages replace ~8 to ~16 individual Components.
( I would use these just for the construction convenience, if for no other reason )

6)
Greatly facilitates using high-Frequency PWM Motor-Speed, and Reversing-Control,
with a simple to understand and implement format.

And all of these reasons are why I would recommend against using discreet Transistors,
( not to mention the reduction in the number of complex Math-Calculations required ).

Yeah-but, yeah-but, yeah-but, they cost ~$10.oo each !!!!, and I'll need 2 of them !!!
Well it all depends on whether You want to blow-stuff-up in an interesting learning experience,
or put together a very competent device
that has the potential to be better than You can buy at any price.

( I've blown-up a lot of stuff, it can be really expensive, or even embarrassing sometimes )
.
.
.

thank you for reply. First i used 9v battery because that was only available in tinkercad. in this project can we use 12v 3a smps?
second, if have IRFZ44N which is easily available here how can i connect mosfest instead of relay in this circuit can you please show me?

 

First, I would look at using higher DCV , you may want to look at the LMD18200, or DRV8833 etc boards similar to the L298. it is rated for 3A.

DRV8833 available here. we can use this module after mosfet right?

 

can we use Q1-Q3=BD678, Q2-Q4=BD677?

 

thank you for reply. First i used 9v battery because that was only available in tinkercad. in this project can we use 12v 3a smps?
second, if have IRFZ44N which is easily available here how can i connect mosfest instead of relay in this circuit can you please show me?

.
For a beginner Project, building a Full-Bridge-Motor-Controller with 4 discrete MOSFETs
will probably be disastrous without using a dedicated Driver-Chip designed specifically for the job.
But, for providing Reversing, and Speed-Controlling abilities,
a Full-Bridge-Controller is practically the only choice there is.

These reasons are exactly why I designed the Circuit that I provided the way that I did.
It's simplicity is very valuable, even though it does cost more, initially, to purchase the parts.

I would never suggest that a new guy try to build a Full-Bridge using Discrete-Components,
it's just entirely too likely to turn into smoke, and be an expensive disappointment.
.
.
.

 

( start rant )
Treadmill-Motor-Controllers are my favorite pet-peeve,
yeah, they "work", kinda-sorta, but they're just junk designed to a price-point.
( end of rant )

All though a little off topic, I would come out in the defense of some controllers, having fixed and worked on a few, they are not all the same. !
The favorites for DIY projects would be the MC-80 & MC2100 series, They are fairly well built, designed constructed and protected, with the latter being PWM and processor operated. Separate to the console processor.
Also the Johnson motor being the choice , after all the Chinese do have the market covered with possessing the majority of the worlds rare earth magnet material.

 

What will be interesting is to see what other portions of the project get built. There is the framework to support the motor and container, the shaft arrangement, some sort of rotary agitator, as well as an enclosure for the control circuit and the power supply. Quite a few details before it will be ready to try out.

 

.
For a beginner Project, building a Full-Bridge-Motor-Controller with 4 discrete MOSFETs
will probably be disastrous without using a dedicated Driver-Chip designed specifically for the job.
But, for providing Reversing, and Speed-Controlling abilities,
a Full-Bridge-Controller is practically the only choice there is.

These reasons are exactly why I designed the Circuit that I provided the way that I did.
It's simplicity is very valuable, even though it does cost more, initially, to purchase the parts.

I would never suggest that a new guy try to build a Full-Bridge using Discrete-Components,
it's just entirely too likely to turn into smoke, and be an expensive disappointment.
.
.
.

ok. can you sketch diagram connected to circuit that i provided so i can understand it. thank you.

 

What will be interesting is to see what other portions of the project get built. There is the framework to support the motor and container, the shaft arrangement, some sort of rotary agitator, as well as an enclosure for the control circuit and the power supply. Quite a few details before it will be ready to try out.

yes definitely, i will update more as circuit does get finalized.

 

ok. can you sketch diagram connected to circuit that i provided so i can understand it. thank you.

.
If You don't understand the Circuit-Schematic that I provided earlier,
then this Project is too advanced for your current Electronics experience level.

I would suggest that You choose a Project that does not require as much specialized control of a Motor,
and less rigorous mechanical-design experience.

I have found that modifying existing products has been very useful to me.

I learned this stuff by spending ~60-years as an occasional tinkerer / hobbyist, and
doing lots of reading of stuff that I really didn't understand at the time.
( way before the Internet happened )
I can't really recommend that anyone else take this route to learning,
it's not very efficient,
especially if You want to specialize in a particular field.
So I can't really offer any advice as to how to start developing your own set of skills.
Maybe some of the other good folks here can give You some more useful guidance.
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.
.

 

Having spent sixty years as a design/project/installation/startup/service electrical/electronic, mechanical design engineer, I agree completely with LQC. And really, to build up a slightly complex circuit successfully requires enough familiarity with the physical portion of the components that a wiring diagram is not needed. I have worked with many electronic technicians and a few "wannabe technicians" during my career, and that has been what I observed.
It is one thing to be able to build a professionally designed kit device and a totally different thing to build a system from a circuit and have it function correctly, from just a circuit schematic.

 

DRV8833 available here. we can use this module after mosfet right?

The DRV8833 is a H-bridge motor driver, similar to the L278 with PWM input signal.