A Look at an Odd Beast - The SEIKO EL-330 (3303)
Jan 27, 2016 19:16:19 GMT -8
Rod, siralan, and 10 more like this
Post by Adrian-VTA on Jan 27, 2016 19:16:19 GMT -8
Hi Guys,
I've had this one sitting around for ages and felt like a challenge, so I pulled a fairly late night getting it back in action.
Rewinding a bit, this is the watch I received that had mushrooms growing in the crystal gasket.
These are odd as they have a crown at 2:30. I think it's an ideal position.
OK so what is the EL-330 anyways?
The 330x series were SEIKO's venture into the electric watch world. An electric watch in most cases retains a conventional balance wheel but the power is provided by a battery, which drives either the balance wheel or the pallet fork with magnets. The magnets are switched on or off either by a tiny metal wire which is pressed by the balance against a pole (acting as a mechanical switch) or by a transistor. They were very short lived because they are quite twitchy and when quartz came out, quartz was much better value for money. Electric watches do not have an IC to manage the watch, they are purely electro-mechanical. They usually have a diode on board to reduce or eliminate sparking on the contacts. The 3303 is a Daini product.
The 3303 is a bit odd in that while most electric watches have one or the other, the 3303 has BOTH. So in this case, the metal contacts (tines) tell the transistor to power the magnets. This is fairly unconventional and the 3303 is the only movement that operates like this.
So here's the complete movement. You can see the "batwing" balance bridge on the left, coil to power up the magnets and the electrics. The white thing is the transistor.
They are a 9J movement. They don't really need more because you don't have a mainspring, so there's not loads of torque wearing the pivots.
I just happen to have the OEM test gear for this movement, and part of that is a screw on power pole which holds the battery in to the movement while working on it. You can make these yourself if need be. In the below pic, the movement is running and you can see the balance swinging around.
The escape wheel and pallet fork are quite unconventional on these movements.
The pallet fork has a bipole magnet attached to the bottom which is what makes it spin round. The power is applied through here rather than in traditional watches where it is applied through the escape wheel.
On the main plate, the iron magnets wrap around where the pallet fork goes, and alternately power up, which is what flicks the pallet fork around. Just like any kind of conventional electric motor.
Also the escape wheel has a "ninja star" bottom and a pawl top. The pawl here is important. Because there is no torque keeping tension on the wheel, it won't continue to move by itself like on a mechanical watch. The pawl retains torque on the wheel (this is a bit tricky to get unless you see it working). When you have finished service, you need to give the balance wheel a flick to get it started.
Here's more detail on the main plate -
Another view -
Minus the train bridge -
The calendar and keyless works are unremarkable. There is no day quick set on this movement. You press the crown to change the date.
And here we are all finished.
I made the decision not to fiddle with this thing timing wise. It runs well and they are twitchy, so I'll leave it well alone.
Here's the timegrapher result after 12 hours running. Pretty good. You can time these with any timegrapher, as they make a tick/tack and run at 21,600 bph, just like a mechanical, but your mainspring is a battery.
I've had this one sitting around for ages and felt like a challenge, so I pulled a fairly late night getting it back in action.
Rewinding a bit, this is the watch I received that had mushrooms growing in the crystal gasket.
These are odd as they have a crown at 2:30. I think it's an ideal position.
OK so what is the EL-330 anyways?
The 330x series were SEIKO's venture into the electric watch world. An electric watch in most cases retains a conventional balance wheel but the power is provided by a battery, which drives either the balance wheel or the pallet fork with magnets. The magnets are switched on or off either by a tiny metal wire which is pressed by the balance against a pole (acting as a mechanical switch) or by a transistor. They were very short lived because they are quite twitchy and when quartz came out, quartz was much better value for money. Electric watches do not have an IC to manage the watch, they are purely electro-mechanical. They usually have a diode on board to reduce or eliminate sparking on the contacts. The 3303 is a Daini product.
The 3303 is a bit odd in that while most electric watches have one or the other, the 3303 has BOTH. So in this case, the metal contacts (tines) tell the transistor to power the magnets. This is fairly unconventional and the 3303 is the only movement that operates like this.
So here's the complete movement. You can see the "batwing" balance bridge on the left, coil to power up the magnets and the electrics. The white thing is the transistor.
They are a 9J movement. They don't really need more because you don't have a mainspring, so there's not loads of torque wearing the pivots.
I just happen to have the OEM test gear for this movement, and part of that is a screw on power pole which holds the battery in to the movement while working on it. You can make these yourself if need be. In the below pic, the movement is running and you can see the balance swinging around.
The escape wheel and pallet fork are quite unconventional on these movements.
The pallet fork has a bipole magnet attached to the bottom which is what makes it spin round. The power is applied through here rather than in traditional watches where it is applied through the escape wheel.
On the main plate, the iron magnets wrap around where the pallet fork goes, and alternately power up, which is what flicks the pallet fork around. Just like any kind of conventional electric motor.
Also the escape wheel has a "ninja star" bottom and a pawl top. The pawl here is important. Because there is no torque keeping tension on the wheel, it won't continue to move by itself like on a mechanical watch. The pawl retains torque on the wheel (this is a bit tricky to get unless you see it working). When you have finished service, you need to give the balance wheel a flick to get it started.
Here's more detail on the main plate -
Another view -
Minus the train bridge -
The calendar and keyless works are unremarkable. There is no day quick set on this movement. You press the crown to change the date.
And here we are all finished.
I made the decision not to fiddle with this thing timing wise. It runs well and they are twitchy, so I'll leave it well alone.
Here's the timegrapher result after 12 hours running. Pretty good. You can time these with any timegrapher, as they make a tick/tack and run at 21,600 bph, just like a mechanical, but your mainspring is a battery.
