EEVblog #435 - 3D Rocker Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: March 05, 2013, 01:26:12 pm
content: You know you want to see what's inside a 3D Rocker Platform.TDA2806A:http://eevblog.com/files/TDA2086A.pdfT410-600 TRIAC:http://www.mouser.com/ds/2/389/CD00002383-108813.pdfDave.

author: Rufus
author_rank: Super Contributor
timestamp: March 05, 2013, 03:02:12 pm
content: The motor is AC induction, shaded pole or something typically used in stuff like fans. You can do crude speed control (or probably torque control) by triac phase angle switching to reduce the effective AC drive voltage.The TDA2086 is a triac phase angle motor controller more typically used with universal brushed motors (dc motors with field magnet coils which allow them to run on AC). The biggest application was probably for washing machines which need high speeds for spinning and accurate low speed for the wash cycles.Made by GEC Plessey Semiconductors and obsolete. The TDA1085 by ON Semiconductors is a similar part which might still be available.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 05, 2013, 05:18:10 pm
content: Quote from: Rufus on March 05, 2013, 03:02:12 pmOf course nowadays you'd do it with a small PIC or similar.

author: N2IXK
author_rank: Frequent Contributor
timestamp: March 05, 2013, 09:54:16 pm
content: These things are PERFECT for agitating an etchant bath for folks who make their own PCBs.Was surprised to see any kind of feedback loop at all. I've had to repair a few lab stirrers and whatnot over the years, and most of them ran straight open loop phase controllers, similar to an incandescent lamp dimmer. The really simple ones simply used a large (25W or so) wire wound rheostat in series with the motor.

author: AlfBaz
author_rank: Super Contributor
timestamp: March 05, 2013, 11:26:18 pm
content: That bar just seems to stop the tray from rotating

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: March 06, 2013, 02:52:20 am
content: Dave, give the thing to Photon. He could perhaps attach a "choke-a-chicken", liven up the tray and give the motor a few thousand volts.I want flames.

author: drewtronics
author_rank: Contributor
timestamp: March 06, 2013, 04:42:40 am
content: I was really kind of disappointed in that choice of teardowns. Where's that awesome old phone from the mailbag the other day? way cooler.

author: G7PSK
author_rank: Super Contributor
timestamp: March 06, 2013, 10:57:29 am
content: You will never have to find a stick to stir paint again. The post at the corner is to stop the plate from spinning the piece at the center is just a face cam, usually a ball bearing mounted onto the shaft at an angle such a system is also called a wobbulator by many in the mechanical world very often used in hydraulic pumps and motors.

author: Skimask
author_rank: Super Contributor
timestamp: March 06, 2013, 02:17:56 pm
content: I still thinks it's a 2D rocker, because over the course of a revolution, the center of the platform doesn't move in the Z axis...But that's just me...I'm weird that way...

author: Len
author_rank: Frequent Contributor
timestamp: March 06, 2013, 04:52:23 pm
content: Quote from: Skimask on March 06, 2013, 02:17:56 pmIf you put Sagan off-centre he'll be rocked in three dimensions.

author: bitwelder
author_rank: Super Contributor
timestamp: March 06, 2013, 08:14:03 pm
content: I did not quite get why the box has two switches, one marked "mains" and one marked "motor".What else is the "mains" supplying power to apart of the motor?

author: fuzzoli
author_rank: Regular Contributor
timestamp: March 06, 2013, 08:45:57 pm
content: ...slightly OT, but will you be planning a teardown and review of the PPS3205T-3S power supply? Thanks - Frank

author: SeanB
author_rank: Super Contributor
timestamp: March 06, 2013, 09:03:33 pm
content: I would guess the reason for 2 switches is because there is a version of this unit that has a heater mat built into the table to warm up the biological samples to a preset temerature, and this would mean there is a third switch for temperature on and off, along with a controller as well. Thus one switch for the unit to turn all off and then switches for the separate functions. Easy to feed the wiring for the heater mat and the temperature sensor up through the stabilising arm so they do not get subjected to excessive flexing and wear.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 06, 2013, 09:50:42 pm
content: Quote from: SeanB on March 06, 2013, 09:03:33 pmWouldn't it make more sense to have one switch on that version?

author: EEVblog
author_rank: Unknown
timestamp: March 06, 2013, 09:56:27 pm
content: Quote from: fuzzoli on March 06, 2013, 08:45:57 pmYes, of course.Dave.

author: T4P
author_rank: Super Contributor
timestamp: March 07, 2013, 05:56:55 am
content: Quote from: Rufus on March 05, 2013, 03:02:12 pmI second that, no brushless motors have their windings on the outer core only induction motors like the ones found in fans

author: Fezder
author_rank: Regular Contributor
timestamp: March 07, 2013, 03:13:10 pm
content: Interesting, newer even heard this machine. And it even has purpose!Overall, great video, entertaining but educating!

author: amyk
author_rank: Super Contributor
timestamp: March 08, 2013, 06:44:21 am
content: The negative voltage supply makes me think the chip might be fabbed in PMOS, like some early mains-powered alarm clock ICs.

author: Mindlesscoolguy
author_rank: Newbie
timestamp: March 14, 2013, 11:44:23 am
content: I have never wanted to sit on something more than this in my (relatively short) life

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 14, 2013, 05:49:23 pm
content: Quote from: T4P on March 07, 2013, 05:56:55 amWhile most BLDC motors have the rotor on the outside, BLDC motors that have the rotor on the inside do exist.