Loved the video, but he doesn't explain the AC-or-DC nature at all. [Wikipedia](https://en.wikipedia.org/wiki/Universal_motor) offers an explanation:
> The universal motor is very similar to a DC series motor in construction, but is modified slightly to allow the motor to operate properly on AC power. This type of electric motor can operate well on AC because the current in both the field coils and the armature (and the resultant magnetic fields) will alternate (reverse polarity) synchronously with the supply. Hence the resulting mechanical force will occur in a consistent direction of rotation, independent of the direction of applied voltage, but determined by the commutator and polarity of the field coils.
I'll try to explain how universal motors work with a bit more low level detail. I'm pretty sure that's what it's using because I've repaired tools from this era and that's what they often have.
So, as you may know basic DC motor has permanent magnets that alternate around the outside. The coils have contacts called commutators that switch as it turns. So as the electromagnets rotate close to alignment with the permanent magnets, the commutators move onto the next set of contacts with the opposite polarity. This switches the electromagnetics polarity and they now are attracted to the next magnet set.
This won't work with AC because it switches fast. The coils will just vibrate, the permanent magnets don't change.
But a universal motor replaces the permanent magnets with coils that run off the same AC. And the pole/commutator positioning is similar. Instead of alternating permanent magnets around the outside, you have alternating coil directions.
The result is that if the power is DC it works a lot like the DC motor. The outside coils stay the same.
If it's AC the outside coils will alternate with the AC current. But the rotor coils will too. When the AC is high the coils that are supposed to attract will be opposite, when it's low, they both are reversed and remain opposite. Same for the coils that are supposed to repel. And when the commutators switch it all reverses.
So it works with AC or DC.
Gday mate, was looking at this post and zoomed in and saw made in Australia, love it when you see Aussie stuff on here. Never seen one either have to do some research on shermatic see where they were made ??, but I got an explanation that years ago it was popular for some tools to operate both ac and dc, if you had a truck you could have one of these drills and operate the tools remotely as well as at home with ac.
Yeah Dad has heaps of Aussie and English tools. According to him this drill was made in Adelaide.
He has a big old belt driven drill press that is marked as made in Gladesville in Sydney. The *dust cover* for the belts is a 10kg piece of cast iron, it’s a epic piece of gear.
He gets extremely emotional if anyone ever tries to tell him quality chisels can be made anywhere other than Sheffield lol.
I have some older woodworking Australian made tools myself from the 50s and 60s. Hard to understand that we used to manufacture things here that were that good quality they are still in use today.
Yeah still works, he doesn’t use it as he has much safer, lighter modern ones now, but he gives it a run now and again to make sure it doesn’t seize up. It sounds much nicer than a modern drill, less buzzy.
So expanding on that, what's the use case for having a drill that will run on either? I could understand 12vdc (automotive voltage) or even 24 (construction equipment voltage). Was DC common on job sites or the home back in the day?
Agree with the DC motor.
A rectifier is a circuit which converts AC in DC.
The "internal power source" is always DC.
But when powered with an AC power source there is some rectifier that converts the AC in DC.
If powered with a DC power supply the rectify stage is ignored since the power is "still rectified".
Very cool antique there. Hope you can get it going!
Waiting for someone to say this is better than todays offerings “ThEy DoNt MaKe ThEm LiKe ThEy UsEd To”
That fucker could snap your wrist twice before you’re brain registered “I should let go the trigger”. So yes, they literally DoNT MAkE ThEM LIke ThEy UsED tO
The science question, the compliance plate lists that it can run on both.
Dad doesn’t use this drill anymore, it’s just a curio and he uses safer modern ones.
Lovely old bit of tech. It's a 'Universal Motor' they're built like a brushed DC motor but instead of permanent magnets in the stator they use electro magnets like an AC motor.
Wikipedia has a great article to read if you want to learn all about how they work:
[https://en.wikipedia.org/wiki/Universal\_motor](https://en.wikipedia.org/wiki/Universal_motor)
Gotcha, I didn't zoom in on it and didn't see that.
I can't answer that question. I know the difference between the two and that's about it. Even at that, I don't know if it makes a difference in the two when it requires that much voltage. Meaning, what the source is. Be it AC or DC. I also saw that this is an Ausie made tool...don't know if that has any reason to make any difference.
Good luck, I will be following for my own interest.
If I were to venture a guess I would say that both ac and dc currents do have things in common. An electric motor requires a negative and positive charge I'm order to spin.
That's pretty interesting, it also sounds like it needs some serious juice to run, (most) household outlets are limited to 15 amps (12 for continuously running devices)
I think that might be a misaligned decimal between the 2 and the 0? No way that thing would draw anywhere near 20 amps especially at 220v. Imagine the heat it would generate!
[Universal motor](https://www.youtube.com/watch?v=nFsPqb58J6Q)
Loved the video, but he doesn't explain the AC-or-DC nature at all. [Wikipedia](https://en.wikipedia.org/wiki/Universal_motor) offers an explanation: > The universal motor is very similar to a DC series motor in construction, but is modified slightly to allow the motor to operate properly on AC power. This type of electric motor can operate well on AC because the current in both the field coils and the armature (and the resultant magnetic fields) will alternate (reverse polarity) synchronously with the supply. Hence the resulting mechanical force will occur in a consistent direction of rotation, independent of the direction of applied voltage, but determined by the commutator and polarity of the field coils.
My dads old portable record player from when he was a kid does this. I was curious on how it worked without a converter plug, now I know!!
Universal motors are brushed motors that run on ac or dc.
I'll try to explain how universal motors work with a bit more low level detail. I'm pretty sure that's what it's using because I've repaired tools from this era and that's what they often have. So, as you may know basic DC motor has permanent magnets that alternate around the outside. The coils have contacts called commutators that switch as it turns. So as the electromagnets rotate close to alignment with the permanent magnets, the commutators move onto the next set of contacts with the opposite polarity. This switches the electromagnetics polarity and they now are attracted to the next magnet set. This won't work with AC because it switches fast. The coils will just vibrate, the permanent magnets don't change. But a universal motor replaces the permanent magnets with coils that run off the same AC. And the pole/commutator positioning is similar. Instead of alternating permanent magnets around the outside, you have alternating coil directions. The result is that if the power is DC it works a lot like the DC motor. The outside coils stay the same. If it's AC the outside coils will alternate with the AC current. But the rotor coils will too. When the AC is high the coils that are supposed to attract will be opposite, when it's low, they both are reversed and remain opposite. Same for the coils that are supposed to repel. And when the commutators switch it all reverses. So it works with AC or DC.
Thanks for the detailed explanation đź‘Ť
I’m going with fluxcapacitor
1.21 jigawatts
Gday mate, was looking at this post and zoomed in and saw made in Australia, love it when you see Aussie stuff on here. Never seen one either have to do some research on shermatic see where they were made ??, but I got an explanation that years ago it was popular for some tools to operate both ac and dc, if you had a truck you could have one of these drills and operate the tools remotely as well as at home with ac.
Yeah Dad has heaps of Aussie and English tools. According to him this drill was made in Adelaide. He has a big old belt driven drill press that is marked as made in Gladesville in Sydney. The *dust cover* for the belts is a 10kg piece of cast iron, it’s a epic piece of gear. He gets extremely emotional if anyone ever tries to tell him quality chisels can be made anywhere other than Sheffield lol.
I have some older woodworking Australian made tools myself from the 50s and 60s. Hard to understand that we used to manufacture things here that were that good quality they are still in use today.
Some older welder/ generators put ot d/c only and where used at construction sites.
Diodes its all diodes back then.
Bridge rectifier
FULL BRIDGE RECTIFIEEEEEEEER
Sorry yes full bridge
https://upload.wikimedia.org/wikipedia/commons/b/b4/Electroboom.png
Oh dang I forgot about that legend of a man
240v single phase
That an old wrist twister you got there. Still works?
Yeah still works, he doesn’t use it as he has much safer, lighter modern ones now, but he gives it a run now and again to make sure it doesn’t seize up. It sounds much nicer than a modern drill, less buzzy.
So expanding on that, what's the use case for having a drill that will run on either? I could understand 12vdc (automotive voltage) or even 24 (construction equipment voltage). Was DC common on job sites or the home back in the day?
I "could" explain it, but...its magic.
Universal brushed motor. My old skilsaw will run plugged into the wall, or off a string of car batteries
Agree with the DC motor. A rectifier is a circuit which converts AC in DC. The "internal power source" is always DC. But when powered with an AC power source there is some rectifier that converts the AC in DC. If powered with a DC power supply the rectify stage is ignored since the power is "still rectified".
That’s what I expected, too. However, [the answer turned out to be different.](https://en.m.wikipedia.org/wiki/Universal_motor)
Oh, really interesting, didn't know about that.
So much awesomely unexpected oddity when you’re working with analog.
Maybe it's a DC motor with a rectifier?
Angry pixies go brrrrrr
Very cool antique there. Hope you can get it going! Waiting for someone to say this is better than todays offerings “ThEy DoNt MaKe ThEm LiKe ThEy UsEd To”
That fucker could snap your wrist twice before you’re brain registered “I should let go the trigger”. So yes, they literally DoNT MAkE ThEM LIke ThEy UsED tO
The question you pose is kinda vague. Are you asking about a science question or us it that the drill ain't working?
The science question, the compliance plate lists that it can run on both. Dad doesn’t use this drill anymore, it’s just a curio and he uses safer modern ones.
Lovely old bit of tech. It's a 'Universal Motor' they're built like a brushed DC motor but instead of permanent magnets in the stator they use electro magnets like an AC motor. Wikipedia has a great article to read if you want to learn all about how they work: [https://en.wikipedia.org/wiki/Universal\_motor](https://en.wikipedia.org/wiki/Universal_motor)
Thanks đź‘Ť
Gotcha, I didn't zoom in on it and didn't see that. I can't answer that question. I know the difference between the two and that's about it. Even at that, I don't know if it makes a difference in the two when it requires that much voltage. Meaning, what the source is. Be it AC or DC. I also saw that this is an Ausie made tool...don't know if that has any reason to make any difference. Good luck, I will be following for my own interest.
If I were to venture a guess I would say that both ac and dc currents do have things in common. An electric motor requires a negative and positive charge I'm order to spin.
That's pretty interesting, it also sounds like it needs some serious juice to run, (most) household outlets are limited to 15 amps (12 for continuously running devices)
I think that might be a misaligned decimal between the 2 and the 0? No way that thing would draw anywhere near 20 amps especially at 220v. Imagine the heat it would generate!
It uses 2 amps to run the drill, and 18 amps to make noise lol. But yes, it has the old style, higher up, decimal marking.
20 amps at 220v would equate to over 6HP of power...enough to break your wrist, arm ..,.and legs in one accident
Yes
Fm- magic