Whats inside Weller WMRT Tweezers

[floobydust]

Maybe look at: Weller WMRP and WMRT compatible soldering station  http://kair.us/projects/weller Offers source code and hardware using PIC16F1788.

[ksilabs]

OK, I do know what's different between RT and RT-MS cartridges.

RT-MS has a separate tip ground on that cylindrical part going into the handle. 3-contact jack pin closes to the tip is NOT connected to the tip as it is in plain RT cartridges. However this difference is superficial -- RT-MS has a PLASTIC washer covering that cylindrical part opening  towards the handle that is not conductive so those two contacts are not connected. Plain RT has a METALLIC conductive washer instead that simply shorts those 2 contacts. I didn't try it but would bet that removing that washer will make RT-MS from RT.

There is also some mechanical difference -- RT-MS has additional thin metal tube with nicely engraved "RT-xMS" and "Weller" over that bare tube piece between the handle and beginning of the heater. I'm almost 100% sure it only serves decorative purpose, nothing else.

Difference in the handle (if it exists at all) is that zero ohm resistor to pin 5 is removed and pin 5 is connected directly to the tip. That would've allowed that fancy 3.5mm "Ground select" jack on WR3M to actually do something (provided nothing else is connected, just WMRP-MS.)  If anything non-MS is connected that jack is purely decorative as that "anything" shorts pin 5 of all 3 connectors to station ground and "grounding jack" makes no sense at all.


I did also a quick teardown of WXDV120 desoldering iron to find out what is that their "totally digital" about. That was total shock as there is actually nothing "digital" in there except PCA9553DP/01 4 LED Blinker with I2C control, 3 LEDs, couple of resistors in voltage divider arrangement (it is probably that "digital ID"), small motion sensor (spring or ball type, much worse that common SW-18010P with a spring) and that's all it has for "fully digital". There is no memory of any kind in the handle. Unless they have something built into their homebrew overmolded connector (I seriously doubt they have -- I've bought a replacement WXP200 cable from Amazon for $8 specifically for teardown purposes and it is original Weller part in their packing having just straight 6 wires, nothing else -- all that "full digital", "stored calibration" and so on is even bigger lie than Volkswagen diesel emission data...

I do also have several plain DXV80 irons and they are almost identical to that "fully digital" one, also having 6 wires and a simpler board without LEDs, PCA9553 I2C LED Blinker and motion sensor.

Also have brand new WXP200 iron and there is nothing "digital" there too except the same parts that are inside WXDV120 iron. BTW, I do also suspect they made 120W desoldering iron off of 80W DXV80 by merely replacing "80" with "120"

There are chances I might be wrong and overlooked something but they are slim. I'm 60 y/o professional Electronics Engineer doing this for living my entire life.

Just to be sure I've purchased a WX2 station to actually hook up a scope (and LA if there IS something digital) to find out what's going on between an iron and the station.

However it looks almost certain that their WX series only standardized irons pinouts so they could throw away that extensive probing/switching circuitry present in WR3M and added blinking LEDs where it was possible (not in WTP90/WMRP/WMRT) and motion sensor switch.

[Spyke]

There is definitely an eeprom located in the WXMT tweezers.

[ksilabs]

There is definitely an eeprom located in the WXMT tweezers.

Maybe. The only place it could be hidden in WXDV120 is under the switch. I did NOT fully disassemble it to remove the board and make exact schematic, will probably do tonight.

WRT that eeprom in WXMT -- did you check the board? What is the eeprom p/n?

I don't have WXMT here, only couple of WMRT handles so can't check. I have WXMP-MS coming my way so will be able to check that one.

Right now from WX line I only have WXP200 and WXDP120 on hand, WX2 station is not even shipped yet.

BTW, the motion sensor is MVS0608.02 from Comus International, available from major vendors and cheaper from www.testco-inc.com -- I've just purchased 25 for retrofitting other legacy  irons.

[ksilabs]

There is definitely an eeprom located in the WXMT tweezers.

Maybe. The only place it could be hidden in WXDV120 is under the switch. I did NOT fully disassemble it to remove the board and make exact schematic, will probably do tonight.

WRT that eeprom in WXMT -- did you check the board? What is the eeprom p/n?

I don't have WXMT here, only couple of WMRT handles so can't check. I have WXMP-MS coming my way so will be able to check that one.

Right now from WX line I only have WXP200 and WXDP120 on hand, WX2 station is not even shipped yet.

BTW, the motion sensor is MVS0608.02 from Comus International, available from major vendors and cheaper from www.testco-inc.com -- I've just purchased 25 for retrofitting other legacy  irons.

OK, I was too quick to draw

I've removed the board from my WXDV120 for close-up inspection and indeed all the fancy stuff was on the back side, not visible with board in place.

I've underestimated Weller guys -- it is 4-layer board packed with quite a lot of stuff.

First of all there is a 4-channel Analog Devices AD7995YRJZ-1 ADC with I2C interface in SOT23-8 package. Then there is TS507 opamp from ST Micro in SOT23-5 and yes, Microchip 24AA04 4Kbit I2C EEPROM in SOT23-5 package as well as some resistors and capacitors.

Everything is perfectly readable by regular tools, nowhere to put any secret codes or read protect so the entire line should be easily reverse-engineerable.

It's getting more and more interesting by the day, having tons of fun

Will try to make a schematic in a day or two...

[ksilabs]

There is definitely an eeprom located in the WXMT tweezers.

Maybe. The only place it could be hidden in WXDV120 is under the switch. I did NOT fully disassemble it to remove the board and make exact schematic, will probably do tonight.

WRT that eeprom in WXMT -- did you check the board? What is the eeprom p/n?

I don't have WXMT here, only couple of WMRT handles so can't check. I have WXMP-MS coming my way so will be able to check that one.

Right now from WX line I only have WXP200 and WXDP120 on hand, WX2 station is not even shipped yet.

BTW, the motion sensor is MVS0608.02 from Comus International, available from major vendors and cheaper from www.testco-inc.com -- I've just purchased 25 for retrofitting other legacy  irons.

OK, I was too quick to draw

I've removed the board from my WXDV120 for close-up inspection and indeed all the fancy stuff was on the back side, not visible with board in place.

I've underestimated Weller guys -- it is 4-layer board packed with quite a lot of stuff.

First of all there is a 4-channel Analog Devices AD7995YRJZ-1 ADC with I2C interface in SOT23-8 package. Then there is TS507 opamp from ST Micro in SOT23-5 and yes, Microchip 24AA04 4Kbit I2C EEPROM in SOT23-5 package as well as some resistors and capacitors.

Everything is perfectly readable by regular tools, nowhere to put any secret codes or read protect so the entire line should be easily reverse-engineerable.

It's getting more and more interesting by the day, having tons of fun

Will try to make a schematic in a day or two...

BTW, it IS 120W -- heater is ~4 Ohm that makes it ~6A @ 24V when cold that translates to ~144W. Temperature sensor is Pt100. 6 wires to the station -- 2 separate wires for the heater, 1 common ground with tip connected to it so no "raised' or "floating" ESD protection is possible as it is hardwired to system common ground in the iron, 1 wire for power (probably 5V, don't know yet) and 2 wires for I2C SCL/SDA.

On the cable connector it looks like they dedicated separate pins for 12V and 24V power (looks like 1 pin for a single 24V and 2 pins for separate 12V powers for tweezers, only one of which is used on WXMP that has only one heater.)

Would be very interesting to find out what their female receptacle on WX station is. I was not able to locate anything like that so far -- there are many 12-pin connectors of similar size but I could NOT be able to find anything with the same contacts arrangement.

If somebody knows what connector they used (cable male plug might be their own as it looks like contacts are potted in epoxy instead of placed in some standard shell but female receptacle definitely looks like something standard) it would be highly appreciated.

The current plan is to put some intermediate standard cheap connectors in the station and make modular adapters for "new" WX-style and old 7-pin custom DIN ones so the station could work with any mix of irons by using proper modules. That would allow to use irons as-is, without any modifications with their existing cables. Adapters for legacy irons might have "conversion" circuitry that would make them look like "new" WX ones to the station no matter what they are.

That would also make possible to make adapters for irons from other manufacturers, with different connectors and make them look native for the station. As the entire control part is going to be developed from scratch it wouldn't be bound to those Weller codes/IDs only so it will be possible to add anything as needed. All source code is going to be GPLed without any secrets so anybody could add whatever features/tools he wants.

So if anybody knows what those WX female receptacles are please share the knowledge...

[Spyke]

Nice work at reverse engineering. I would imagine that plug is purely a custom job. Its good news that Weller have not employed some pesky DRM scheme even though they could have, as from what I understand the temperature info also gets set digitally down the wire, by use of that ADC being very close to the TC as part of the tool handle. Must be a very tight control loop.

[Spyke]

The cool thing you could fab one out of PCB with the proper rounded pins in the correct spot, would be great to test with incase you need a special run of jacks.

[Howardlong]

Note people are having reliability problems with the Weller tweezers.
The housing aluminium EMI coating flakes off, and the conductive flakes short the PC board.

Which model?

I've been using the same pair of WMRT tweezers for well over a decade with no signs of anything flaking off.

[ksilabs]

The cool thing you could fab one out of PCB with the proper rounded pins in the correct spot, would be great to test with incase you need a special run of jacks.

Sure, but I care less for plugs -- all WXxyz irons already come with their cables so it is only relevant for possible retrofitting legacy irons with WXxyz internals thus converting them to digital. Even that is not an issue as you can use whatever connector you want and make an adapter for its plug.

What I do care about is getting the matching female receptacles for ORIGINAL Weller WXxyz plugs for WX adapters so irons could be used as-is, without any modifications. The problem is those connectors have quite unusual contacts arrangement so I could not find anything like that so far.

In the meantime I'm going to make a WXDV120 board schematic today or tomorrow and, probably, do a board layout and order some boards for retrofitting legacy DXV80 irons.

I do already have (either on hand or in transit to me) WXMP-MS, WXMT-MS, WXP120, WXP200, WXHAP200 irons so I would be able to make retrofit boards for their legacy counterparts. I do also have legacy WP80, WMP, HAP200, lot of DXV80s, couple of WTA50s, several WTP90s so would be able to make something similar for those. WTP90 is my current favorite -- I like that iron. It is very light and capable of delicate jobs with its default XNTA tip but has enough juice for much heavier jobs with THM tips (BTW those are discontinued by Weller so go get yours while they are still available.) I do also have a couple of spare heating elements for WTP90 so I can keep them with some particular tips and change them as easily as RT tips.

Initial plan for the station is to make it 6-channel with built-in Air/Vacuum and Vacuum Pickup pumps, Air/Vacuum would have 2 connections for 2 tools each with built-in valve switching it between corresponding tools. Vacuum pickup would get a pedal and built-in vacuum release valve. It would be able to power any tool, legacy and WX, Weller or not with a proper adapter. Thinking of something looking like WR3M but with additional 3 tools connectors on the right so control panel would be in the center with 3-tool panels on both sides.

[Howardlong]

Some pics inside WMRT

I believe the SMD part marked 110 may be a temperature sensor KTY82-110, probably a safety feature.

The long thin white thing is a reed relay to detect whether the tweezer is in the stand or not.

The casing is plastic. The apparent case marks are evidence of the operator's fingers mating with super glue at some time in its history!

The internal metallic block doesn't usually have L R written on it, that was so I put it back together the right way.

[ksilabs]

Some pics inside WMRT

I believe the SMD part marked 110 may be a temperature sensor KTY82-110, probably a safety feature.

WMRT is not interesting, nothing to write home about... WXMT would've been more interesting but I will do it myself once the shipment arrived.

KTY82-110 is not a safety feature -- it is used to measure thermocouples (there are two in RTW, one per side) cold junction temperature to calculate the actual hot junction (tip) temperature.

[Howardlong]

Some pics inside WMRT

I believe the SMD part marked 110 may be a temperature sensor KTY82-110, probably a safety feature.

WMRT is not interesting, nothing to write home about... WXMT would've been more interesting but I will do it myself once the shipment arrived.

KTY82-110 is not a safety feature -- it is used to measure thermocouples (there are two in RTW, one per side) cold junction temperature to calculate the actual hot junction (tip) temperature.

Glad I bothered then. Sorry to disappoint you.

In case it had escaped your notice, the title of the thread is "What's inside Weller WMRT Tweezers". Mine was the first post to directly address this within the thread.

Have a great day.

[ksilabs]

Some pics inside WMRT

I believe the SMD part marked 110 may be a temperature sensor KTY82-110, probably a safety feature.

WMRT is not interesting, nothing to write home about... WXMT would've been more interesting but I will do it myself once the shipment arrived.

KTY82-110 is not a safety feature -- it is used to measure thermocouples (there are two in RTW, one per side) cold junction temperature to calculate the actual hot junction (tip) temperature.

Glad I bothered then. Sorry to disappoint you.

In case it had escaped your notice, the title of the thread is "What's inside Weller WMRT Tweezers". Mine was the first post to directly address this within the thread.

Have a great day.

Sorry if it offended you -- I didn't mean it...

[Spyke]

Since this topic has woken back up its perked my interest again. Here is the internals to the WXMT tweezers. Definitely more interesting than the RT, probably no room for the LED blinker chip.

[ksilabs]

Since this topic has woken back up its perked my interest again. Here is the internals to the WXMT tweezers. Definitely more interesting than the RT, probably no room for the LED blinker chip.

Looks pretty similar to my WXDV120 board. Almost same components and schematics.

Spent entire evening yesterday after my day job making Altium symbols and footprints for those components, hopefully will get to actual schematics tonight. Doing it the proper way as I want not just draw a crude schematics but also clone those boards and order a couple of panels along with stencils.

[Hydron]

There has been a fair bit of work on the weller WX series irons over on mikrocontroller.net: https://www.mikrocontroller.net/topic/367344
Everything other than my contribution is in German but google translate does a reasonable job on it. Nobody has had any luck with finding an off-the-shelf connector but I managed to 3d-print one which works well enough for my WXMT tweezers.
I have also had the tweezers working with a controller I lashed up on a breadboard but it is very rough (and needs some tweaking to the temperature calculation) so I haven't posted about it.

[ksilabs]

There has been a fair bit of work on the weller WX series irons over on mikrocontroller.net: https://www.mikrocontroller.net/topic/367344
Everything other than my contribution is in German but google translate does a reasonable job on it. Nobody has had any luck with finding an off-the-shelf connector but I managed to 3d-print one which works well enough for my WXMT tweezers.
I have also had the tweezers working with a controller I lashed up on a breadboard but it is very rough (and needs some tweaking to the temperature calculation) so I haven't posted about it.

OK, we'll see what I will find by reverse-engineering that WX2 station that is on its way to me now...

It might well be a totally custom connector made to Weller's order or even manufactured in-house One solution would be to replace it with readily available connectors from e.g. CNLINCO that are really high quality and have proper power rating like e.g. this one:

https://www.ebay.com/itm/153159218792

but it's unlikely people would cut their original Weller connectors and replace it with a generic one or replace the entire cable...

[ksilabs]

BTW, just got my WXMT-MS set delivered and can tell now what's the difference between MS and non-MS versions of both legacy and WX versions is.

The MS versions of WMRT/WMRP/WXMP/WXMT has a totally separate tip grounding all the way to the cable plug. WXMT-MS has a pogo pin in addition to that 5-pin Binder connector that contacts the metal body and has white wire soldered directly to that pogo pin so actual connection to the cartridge is 6 wires, not 5.

The non-MS version has its tip grounding wire connected to a common pin inside the cartridge so there is no separate tip grounding there -- connection to the cartridge is 5 wires.

And I was wrong thinking that common ground is connected to the tip. It is connected to one of the heater's terminals. Reworking (beautyfing) the WXDV120 schematic now, will post later tonight along with the board photos (just got a ring light so can make macro pictures now).

[ksilabs]

Here is the full WXDV120 Schematic...

[ksilabs]

Here is the full WXDV120 Schematic...

This is the final revised WXDV120 schematic and board layout. Each heater terminal connection takes an entire internal layer and Heater2 is NOT used as a ground plane -- it is just connected to the signal ground at one point at cable terminal. All signal nets are routed on top and bottom layers. It is 1.6mm 4-layer board with components on both sides.

[ksilabs]

Original board photos...

[langwadt]

Note people are having reliability problems with the Weller tweezers.
The housing aluminium EMI coating flakes off, and the conductive flakes short the PC board.

ours just killed a few boards, the tips got loose in the holder and pushed in shorting to power

[Hydron]

BTW, just got my WXMT-MS set delivered and can tell now what's the difference between MS and non-MS versions of both legacy and WX versions is.

The MS versions of WMRT/WMRP/WXMP/WXMT has a totally separate tip grounding all the way to the cable plug. WXMT-MS has a pogo pin in addition to that 5-pin Binder connector that contacts the metal body and has white wire soldered directly to that pogo pin so actual connection to the cartridge is 6 wires, not 5.

The non-MS version has its tip grounding wire connected to a common pin inside the cartridge so there is no separate tip grounding there -- connection to the cartridge is 5 wires.

A quick question about the RWT MS tips - from your description it sounds like the difference is mostly in the handle with the pogo pin - is there anything to prevent a MS tip being used in a non-MS iron? I assume the 5 pin connector/pinout etc is the same? Or would a modification to the tip PCB or wiring be needed (not a deal breaker if I can get a MS tip for a significant discount)?

[ksilabs]

BTW, just got my WXMT-MS set delivered and can tell now what's the difference between MS and non-MS versions of both legacy and WX versions is.

The MS versions of WMRT/WMRP/WXMP/WXMT has a totally separate tip grounding all the way to the cable plug. WXMT-MS has a pogo pin in addition to that 5-pin Binder connector that contacts the metal body and has white wire soldered directly to that pogo pin so actual connection to the cartridge is 6 wires, not 5.

The non-MS version has its tip grounding wire connected to a common pin inside the cartridge so there is no separate tip grounding there -- connection to the cartridge is 5 wires.

A quick question about the RWT MS tips - from your description it sounds like the difference is mostly in the handle with the pogo pin - is there anything to prevent a MS tip being used in a non-MS iron? I assume the 5 pin connector/pinout etc is the same? Or would a modification to the tip PCB or wiring be needed (not a deal breaker if I can get a MS tip for a significant discount)?

Everything else in MS/non-MS tips is almost identical. The only difference is where that grounding wire is connected. You can use MS insert in non-MS handle but it will get the tip floating i.e. not grounded. You will either have to install that pogo pin and connect the grounding wire in the handle to that pin or connect grounding wire to the proper pin in the cartridge itself to have it grounded.