Hitachi magic wand repair

Best toy ever made..Next to a John Deer LoL And someone made a speed controller finally too.

http://www.amazon.com/Wand-Massager-Speed-Controller-Hitachi/dp/B000YA7Z22/ref=pd_rhf_ee_shvl2
Along with many attachments as well

Yes, although the speed control gets some questionable reviews, and some seem to suggest that the motor in the hitachi wand is brushless... I'm trying to build a speed controller of my own, and knowing the type of the motor is fundamental to the design. Can anyone tell me?

@SweetErica: Well let me know when your Hubby gets round to disecting the wand. I'd like to design my own speed control, but knowing the voltage and current direction (AC or DC) is important for the design.

@temp256: That schematic (currently a dead link to tinypic) would be priceless.

Magic Wand R&R and PoP

nb: This is all based on a 2 yr old (apparently) genuine Hitachi MW which I own.

Removal:

1. Look down the shaft into the handle of the unit. Flex the head aside to remove the screw, which connects the ring to the base (collar) of the head.

2. Pry ring up and off of the handle. Inside the ring are 3 cutouts that can be hooked.

3. Remove the screw 2" (5cm) from the cord end of the handle (opposite side from the switch).

4. Separate the two handle halves. The side without the switch may be removed leaving the motor and head-collar attached to the switch side.

5. The motor may be removed by lifting the side away from the head and sliding it down.

6. The collar of the head may be pried out of the handle and slid off the white motor fan shaft.

Restoration:

a) When attaching head and motor, note that the silver spring has an extension which fits into the slot on the white plastic fan shaft.

b) After placing head into handle, note position of screw hole in the head collar for re-attaching the ring.

c) Reverse disassembly steps.

The head:

Vibration is obtained by rotating an eccentric (off balance) weight inside the head.

The padded cover may be removed by prying the cover edge away from the head all around at the base of the head. Two screws (shellacked) and tape join the two metal halves of the head base. Opening them exposes the rotating shaft and weight.

The head connects to a collar at the handle via a hollow rubber coated spring, through which an inner spring shaft rotates. Thus the head can flex at any angle.

The motor:

The motor is part "e52382-d-pc", a DC motor used in small appliances. It is not brush-less, and should be run at a constant voltage.


The motor appears to be "permanently" lubricated, and maintenance is never required.

The circuitry:

The power switch is three position, off, high, and low. The low terminal is connected to the high terminal through a diode so that the low setting delivers only 1/2 of the AC current wave form, clipping the negative going portion.

The power leads are connected to the motor through a full wave rectifier bridge. This inverts the negative AC pulses into positive pulses, and combines them with the positive pulses for 120 hertz pulsed DC. When the input wave form is clipped (power switch at low setting), no negative pulses are available to the bridge, so the output is only 60 hertz pulsed DC.

Sorry I haven't been around lately. I updated the images. They're hosted on the literotica forum servers now, so hopefully they'll stick around this time.

@memma, there is no transformer. The motor runs on rectified mains voltage. It's a brushed DC motor, which runs on the pulsed DC from the bridge rectifier.

The best way to build a speed controller is to use a triac circuit. They're quite simple, and are often used to control brushed motors. I've built a couple in the past, but I really have no need to reduce the speed of my wand. If anything I want more power.

Speaking of which, a simple modification can provide a slight increase in power. Simply connect a large capacitor in parallel with the motor. This will reduce the rippled output of the bridge rectifier, and give a slight increase in power.

Also, I highly suggest adding a snubber circuit across the motor. This will help reduce RF interference. It's quite annoying when the wand interferes with a wireless mouse...

temp256 said:

Guy thing? You're talking to a girl who has a subscription to Maxim. Maxim semiconductor.

I'll post some pics later. It's an interesting, but cheap design.

Better techno porn.

Click to expand...

Never mind a minor case of cranial rectal inversion. (LOL)

Mike

I fixed that one too. Stupid free image hosts...

Sorry it was my fault. I didn't bother to look at the original post date. I will look though.

From hat you said it is a cheep and lazy design. I will say the Japanese do business differently than we do here. They have "business relationships " with certain companies with whom they keep going for years. So they may be getting the parts at a relatively deep discounts. So they may be able to make it for say $15 and sell the thing here for $50+.

From your description it does sound like an AC motor with a rheostat (Pot) May work longer and bettor but you would not need to replace it in a few months ether.

Mike - Old navy Electronics Technician.

Potentiometes are a terrible way to drive AC motors. The proper way is to use a variable frequency drive circuit. If you're going to make one of those, you might as well go all the way and use a brushless DC motor instead. They're quite powerful, and far more efficient.

I really want to build a three phase vibrator now...

Thank you!

temp256 said:

I fixed that one too. Stupid free image hosts...

Click to expand...

That's great, thank you! I know exactly what I'm up against now.

temp256 said:

really have no need to reduce the speed of my wand. If anything I want more power.

Click to expand...

Sure, I'm with you there, but it's not just about the speed - it's about the pattern

I tried to increase the power using the method I described earlier. It worked great in the lab: even low speed was faster than the normal maximum, and high speed was faster yet. So I soldered it up, and tried it again.

Bzzzzzrrrr.....*pop*. Out go the lights.

It seems some idiot connected the electrolytic capacitor backwards, and blew it out. Unfortunately said idiot was me. Not a problem. I've blown up bigger capacitors than this. Once even intentionally. I'll simply replace it and try again.

*Pop*. This time I manage to trip both the circuit breaker and the GFI. Oh, and the power switch on the wand welded itself shut.

Still not a problem. I've welded power switches shut before, for bigger motors than this. They're easy enough to fix. I was starting to get suspicious at this point, so I started testing the diodes. They all read as dead shorts. In both directions.

As best as I can tell, when the capacitor failed, it shorted out. This caused high current to flow through the diodes, frying them into conducting both directions. Turning on the wand is now equivalent to sticking a paperclip in an outlet.

Fortunately, this likely means the motor was protected. Diodes are easy to replace, and I'll use better ones than the original. It's too late right now, but hopefully I can get it working again tomorrow. If not, I'll have to build a shrine for the wand--a martyr to the cause of perpetual horniness.

Well, I replaced all the diodes. I removed the old ones, and made sure the motor was still good. I soldered the new ones in place, and tested it out.

*BAM* The diodes exploded, tripping the breaker once again.

Then I realized another stupid mistake: the diodes were only rated to 20 volts. I replaced the diodes yet again, this time with a beefy 600 volt 20 amp bridge rectifier. I carefully plugged it in again.

*Whhhrrrrrr* Success! I got it working just like it was originally. Of course, this isn't what I set out to do...

I added the decoupling capacitor again, this time checking the polarity several times. It still worked, and the motor was noticeably faster. Then I added a pair of filtering capacitors to reduce electromagnetic noise. The only complaint I've had with this vibrator is it causes interference with my wireless mouse.

I put it all back together, and it still works. I haven't had a chance to test it properly, but I will in the near future.

I've included a new schematic. My modifications are in violet. The filtering capacitors are connected to the metal case of the motor via a mounting screw.

With this, my 500th post, I just became a Literotica Guru. How appropriate.

You want to be VERY careful working on line operated equipment. Line snubber caps are typically very high voltage (1 - 4KV pulse tested) so that they do not arc over during line faults, or ligtening strikes. The caps should be rated (X2, Y2 etc. rating) for use in a position like that so that they are designed to fail open or shorted as appropriate for safety reasons. Those look like common film type caps and I would not use them there. I would go across the motor rather than to the case, you do not want to encourage any line power going to any metal inside the case (when a 3 prong plug is not used) even if it is insulated.
It is actually a bit more complicated. Since you do not have a safety ground you want an X2 type of safety capacitor with it going directly across the motor, not to the case. Here is a simple discussion, you should probably read some of the more professional ones if you really want to use such a modification:
http://www.justradios.com/safetytips.html

I really cannot encourage working on line operated equipment.

.....

Sir Victor, I am by no means an amateur. I've been working with electronics all my life, and I know how to handle line powered devices. I maintained proper isolation when powering up the wand.

The small capacitors are not line filters, but snubbers for the motor's back EMF. Connecting them to the case is the best way to reduce RF interference. I've seen this design used before, and it works fine. The motor case is physically isolated from any other metal parts. The air gap is larger than the gap between the power switch frame and a live wire, so there's nothing to worry about.

If the capacitors fail closed, it will be no different from the motor shorting out, or a loose wire touching. The circuit breaker will sense the short, and trip. The diodes may or may not survive, but I consider them expendable in such a scenario. A fuse would probably be a good idea if I were to redesign it, but the original doesn't have one.

I too despise planned obsolescence. I have an idea for a completely new style of vibrator I'd like to build, but I have no one to help me. If it works well, it might even be marketable.

What sort of person would you need to help you, temp256?

mm

I need someone who can design electromagnets. The theory is simple, but I can't find a good practical guide. I can probably handle the rest of the electronics myself, but it never hurts to have someone else check it.

And of course I'll eventually be needing testers.

temp256 said:

Sir Victor, I am by no means an amateur. I've been working with electronics all my life, and I know how to handle line powered devices. I maintained proper isolation when powering up the wand.

The small capacitors are not line filters, but snubbers for the motor's back EMF. Connecting them to the case is the best way to reduce RF interference. I've seen this design used before, and it works fine. The motor case is physically isolated from any other metal parts. The air gap is larger than the gap between the power switch frame and a live wire, so there's nothing to worry about.

If the capacitors fail closed, it will be no different from the motor shorting out, or a loose wire touching. The circuit breaker will sense the short, and trip. The diodes may or may not survive, but I consider them expendable in such a scenario. A fuse would probably be a good idea if I were to redesign it, but the original doesn't have one.

I too despise planned obsolescence. I have an idea for a completely new style of vibrator I'd like to build, but I have no one to help me. If it works well, it might even be marketable.

Click to expand...

I referred to them as line snubbers right at the start of my post; I know what they are:
" Line snubber caps are typically very high voltage"
It in fact does not matter what you call them, they are subject to line voltages and therefore should be a type of cap rated for very high pulsed voltages such as the type that I pointed out. Doing this wrong could be lethal and therefore you should not be so stubborn. It is clear that you do not want to hear any suggestions or warnings and therefore I'll just say good luck to you. More for you to read:

http://www.mshi-tech.com/franchisedlines/pdf/johanson_dielectrics/jdi_training-safety_2008-01.pdf

http://my.execpc.com/~endlr/line-filter.html

How about this:
http://www.sybian.com/sybianindex.html

temp256 said:

With this, my 500th post, I just became a Literotica Guru. How appropriate.
Attached Images
modified.jpg (96.2 KB, 36 views)
filter_capacitors.jpg (78.8 KB, 29 views)
frame_screw.jpg (72.8 KB, 28 views)
decoupling_capacitor.jpg (97.6 KB, 32 views)
schematic2.png (2.3 KB, 32 views)

Click to expand...

Thanks for the pics. I like the quality of your work; it says a lot.

Do you know a good source for replacement parts (e.g. switch, motor)? Diodes are easy. My switch stopped working for the low setting; I finally had to take it apart and fix it by tweaking the rocker plate.

BTW, with regard to variable speed; I know the new 120VAC LED lights can't use conventional dimmers for incandescence; so, they've come up with pulsed dimmers for them. I haven't looked too see what the circuit is like; but perhaps it could be modified to pulse the 120VDC. There may even be an off the shelf IC chip that could do it. It reminds me of an old High School project for variable speed control circuit that utilized a SCR.

Color organs were fun too (Sorry, drifting off topic).

Led to this forum by searching Google for "how to change the cord on hitachi magic wand." Can someone provide simple steps and a picture? Wand's on the blink AND the bank account's empty...

violettrefusis said:

Led to this forum by searching Google for "how to change the cord on hitachi magic wand." Can someone provide simple steps and a picture? Wand's on the blink AND the bank account's empty...

Click to expand...

Temp's description in one of the early posts should do it.

Open it
Unsolder the incoming wire
Solder the new wire in the same place.

On another note.

A virtual hug to Temp256!





I'm a hardcore sapiophile myself, and a happy one, since I'm married to a well trained she-nerd.




Do any of you have a picture of how the wand changes rotation to vibration.
I know that it is probably just an eccentric weight, but how about size, shape and bearings?

temp256 said:

I've included a new schematic. My modifications are in violet. The filtering capacitors are connected to the metal case of the motor via a mounting screw.

Click to expand...

Ah... thanks! This explains why the original design caused so much radio frequency interference.

My wife and I bought a Hitachi Magic Wand about ten years ago (with a separate transformer for operation on UK mains voltage) and it was almost unusable for this reason. We had to wait for our neighbours to go out before turning it on because we knew that it was interfering with radio and television reception within at least a few metres.

I tried clamping a large ferrite filter around the cable where it exits the Wand, but to no avail. Clearly the unwanted RF energy was radiating directly from the motor through the unscreened plastic enclosure. I think the only effective solution would have been to add suppression capacitors as above, but I wasn't prepared to open up the Wand and potentially compromise the safety of the design.

We recently purchased a more modern (non-Hitachi) Magic Wand, which is designed for UK mains voltages and therefore much more convenient for us. It seems that it was also subject to more stringent EMC standards, as it doesn't appear to cause any perceptible problems with radio and television equipment nearby. So... now we can turn the radio up loud and use it even when our neighbours are at home!
.

violettrefusis said:

Led to this forum by searching Google for "how to change the cord on hitachi magic wand." Can someone provide simple steps and a picture? Wand's on the blink AND the bank account's empty...

Click to expand...

browse a bit...you might find you don't need it.

We don't have fun,




She'll not have fun.