EEVblog #472 - JBC CD-2BB Soldering Iron Teardown

[robrenz]

If you use several tips and/or do a lot of soldering it becomes expensive. I use about 3 different tips regularly, so it would be around AUS$ 120 (EUR 92) for a new set. For my I-Tool a standard tip costs EUR 8 and a spare heater element is EUR 80. And the heater itself will outlive several tips (as the irons I had before). It's like the inkjet printers with combined ink & printhead cartridge vs. separated print head and ink tanks.

I am not bashing your I-Tool but having a separate heater and tip guarantees that the performance on high thermal demand joints will not be in the same league of JBC, Ersa or Metcal.

[KJDS]

If you can't justify a new JBC iron, analogue models are often available second-hand for very reasonable prices, and thanks to the excellent build quality are likely to be robust and reliable. I recently picked up an AD2700 for £87 (about $130). It offers similar thermal performance to the CD-2BB and looks and performs like a new unit. A seller on eBay recently had a range of new tips for £9 each, so accessories don't need to be outrageous.

I believe KJDS, who is a member of this forum,  sells used JBC kit from time to time.

I just picked up a load of JBC kit yesterday. My arms now ache, though mostly for the two tonnes of scrap that I carried out to a lorry and the other tonne of possibly useful stuff. Yesterday I learnt not to bid on something described as "contents of room" without visiting the room. There was a lot of junk not in the photos.

Amongst the normal JBC irons are some separate stands and cables to connect them back to the base unit. I also collected a dozen or more Metcals and some interesting Pace stuff. They are all very good irons, will try and find some time to spare to post more details at the weekend.

[iXod]

Why all the processing power?

/watch?v=IhZORsiawKc

Its there marketing vid. It describes how important it is to:

1. quickly heat the tip
2. regulate the temperature
3. most importantly, avoid overshoot

This is also how they get radically increased tip life (the auto-shutoff also helps with this).

Trying this with a few 3-terminal semis ain't going to accomplish the same results.

Not A Shill

[M. András]

one fail point though ... the tip is grounded ... BAD DESIGN !
there should be a 1 meg resistor between tip and ground. ( long body ,or three 1206 in series to avoid flashover )

you want a pathway from tip to avoid ESD problems.
you may want to put a 100pF cap in parallel with 2/3 of the total 1 meg resistance to deflect fast transients.

having the tip shorted hard to ground is bad. very bad.

the wd1m i have have a nice external ground plug, if its not plugged in the bottom of the unit the iron itself is grounded with 100k resistance if you plug it in it cuts the conection to the mains earth and you can solder to that plug any value resistor you want, there must be some reason they did a "high end" station this way with directly grounded tip. user manuals arent too detailed

[madires]

If you use several tips and/or do a lot of soldering it becomes expensive. I use about 3 different tips regularly, so it would be around AUS$ 120 (EUR 92) for a new set. For my I-Tool a standard tip costs EUR 8 and a spare heater element is EUR 80. And the heater itself will outlive several tips (as the irons I had before). It's like the inkjet printers with combined ink & printhead cartridge vs. separated print head and ink tanks.

I am not bashing your I-Tool but having a separate heater and tip guarantees that the performance on high thermal demand joints will not be in the same league of JBC, Ersa or Metcal.

Got no problems with large connectors or ground planes. The i-Tool is connected to an ERSA i-CON2 ;-)

[madires]

the wd1m i have have a nice external ground plug, if its not plugged in the bottom of the unit the iron itself is grounded with 100k resistance if you plug it in it cuts the conection to the mains earth and you can solder to that plug any value resistor you want, there must be some reason they did a "high end" station this way with directly grounded tip. user manuals arent too detailed

The manual for the i-CON states, that the station is "hard gounded in accordance with Military and ESA standard".

[FrankBuss]

-external eeprom is because dspic33's, pic24h's and pic32's don't have internal eeprom

The dspic has no internal EEPROM, but it can program its own flash memory. But only 10,000 erase/write cycles are guaranteed, which might be the reason for the external memory. Looks like they expect that you change the temperature a lot. It is the M24C16, a 16 kBit I2C EEPROM, which you can get for 20 cents at digikey in larger quantities. Can't find a guaranteed number of erase/write cycles, but usually it is millions of times for EEPROMs, and even more, if the software uses a good wear leveling algorithm.

[mikeselectricstuff]

-external eeprom is because dspic33's, pic24h's and pic32's don't have internal eeprom

The dspic has no internal EEPROM, but it can program its own flash memory. But only 10,000 erase/write cycles are guaranteed, which might be the reason for the external memory. Looks like they expect that you change the temperature a lot. It is the M24C16, a 16 kBit I2C EEPROM, which you can get for 20 cents at digikey in larger quantities. Can't find a guaranteed number of erase/write cycles, but usually it is millions of times for EEPROMs, and even more, if the software uses a good wear leveling algorithm.

The  endurance issue can be worked around, e.g. by a timeout to wait a while before writing, however it is still a PITA as you have to deal with erase block sizes, and dick around with linker configs to allocate the flash. Adding an eeprom is often much just easier, and cost is minimal.
I suspect another reason for using this chip is that Microchip provide lots of libraries for LCD control, DSP etc. 

[Rufus]

I suspect another reason for using this chip is that Microchip provide lots of libraries for LCD control, DSP etc.

It isn't a cheap part at $5.32 5k up on the Microchip site so it seems a strange choice to me. The Microchip graphics library isn't worth much - you can probably buy something better for $1000.  Can't really believe it takes 256k of FLASH or fast ADCs or DSP instructions or many MIPS to run a temperature control loop for a soldering iron.

100 pin package plenty of which look unused. They would save about a $ going to a 64 pin package and another dropping to 128k FLASH.

If the LCD has no controller and they drive in with the dsPIC ram and dma it might help justify the choice, otherwise it looks like cost wasn't much of a consideration for this design.

[robrenz]

I am not bashing your I-Tool but having a separate heater and tip guarantees that the performance on high thermal demand joints will not be in the same league of JBC, Ersa or Metcal.

Got no problems with large connectors or ground planes. The i-Tool is connected to an ERSA i-CON2 ;-)

My apologies, I mistakenly assumed that a separate heater and tip would not be capable of as fast a control loop as a integrated tip/heater/sensor.

[cthree]

My ghetto style ws51 does a decent job for what I need. If I find myself wanting Ill keep this unit in mind.

[Rasz]

I suspect another reason for using this chip is that Microchip provide lots of libraries for LCD control, DSP etc.

It isn't a cheap part at $5.32 5k up on the Microchip site so it seems a strange choice to me. The Microchip graphics library isn't worth much - you can probably buy something better for $1000.  Can't really believe it takes 256k of FLASH or fast ADCs or DSP instructions or many MIPS to run a temperature control loop for a soldering iron.

100 pin package plenty of which look unused. They would save about a $ going to a 64 pin package and another dropping to 128k FLASH.

If the LCD has no controller and they drive in with the dsPIC ram and dma it might help justify the choice, otherwise it looks like cost wasn't much of a consideration for this design.

Im sure choice had nothing to do with potential 60mips performance. Saving a buck? Its like advocating Bentley should save some money switching to Philips Stereo systems, after all they are good bang for the buck in home entertainment market.
Performance of this iron has nothing to do with Pid control loop, and everything with heater/tip quality.

[Rufus]

Saving a buck? Its like advocating Bentley should save some money switching to Philips Stereo systems, after all they are good bang for the buck in home entertainment market.

Damn, I never thought of adding 128k of FLASH full of FFs and 40 no-connect pins on the processor to improve the quality and reliability of my designs.

[Rasz]

Saving a buck? Its like advocating Bentley should save some money switching to Philips Stereo systems, after all they are good bang for the buck in home entertainment market.

Damn, I never thought of adding 128k of FLASH full of FFs and 40 no-connect pins on the processor to improve the quality and reliability of my designs.

dsPICs are higher grade parts compared to Atmega8s.

[BravoV]

dsPICs are higher grade parts compared to Atmega8s.

Interesting, are there any "trustworthy" references supporting that claim ?

[poorchava]

Im sure choice had nothing to do with potential 60mips performance.

dspic33f's go only up to 40MIPS, dspic33e's go up to 60.

[madires]

Got no problems with large connectors or ground planes. The i-Tool is connected to an ERSA i-CON2 ;-)

My apologies, I mistakenly assumed that a separate heater and tip would not be capable of as fast a control loop as a integrated tip/heater/sensor.

No worries! :-) The first time I used the i-Tool I was amazed how fast that tiny iron was able to heat up and output 150W if required. And you can adjust the control loop any time for optimizing the heating (three levels from low thermal load with no overshoot to high thermal load with overshoot). The display has a bargraph at the bottom to display the power currently used for heating. It's a good indicator when to go for a larger tip or to adjust the control loop. BTW, a single tool i-CON with the i-Tool costs as much (or less :-) as the JBC from the teardown.

[Salas]

ERSA has great expertise in industrial soldering train like machines and hand tools. I always liked their tips for solder flow. Metallurgical know-how obviously. In some thermal recovery and overshoot consecutive joints tests (marketing data) the JBC was the more consistent, followed closely by Metcal, the ERSA was kinda shaky, but the big I-Con is very parametric to set as you say. The ~13MHZ bigger dual port Metcal has a power indication bar too. The JBC uses a lot the peak power electrical push thing to heat up fast and to stay dynamic. I don't know what that means for tip/heater combo life when soldering high mass all the time. Professional users would know the parts exchange cost long term factor.

[brabus]

Saving a buck? Its like advocating Bentley should save some money switching to Philips Stereo systems, after all they are good bang for the buck in home entertainment market.

Damn, I never thought of adding 128k of FLASH full of FFs and 40 no-connect pins on the processor to improve the quality and reliability of my designs.

Maybe it's just a production constraint, probably they use the same uC on the whole series of JBC soldering irons, also for the stations with three or four tools.
I don't think it's a matter of quantities, production is just much easier if BOM is somehow similar for every product; I'm thinking about the hardware guys, but the firmware ones as well.

There's only one way to discover it: tear down 'em all!!! 

[Fezder]

Nice video, again! I'm bit confused about hard-earth on the tip, is it the same thing that must be on lookout like say, 'scopes earth, when tinkering with live circuits? BUT, when is it really necessary to solder live electronics? could someone tell? thanks!

[ddavidebor]

Only for change a  battery

[abyrvalg]

There's only one way to discover it: tear down 'em all!!! 

Done, CD/CF series firmware is ~240k after stripping. dspic's instruction encoding looks a bit inefficient, there are lots of zeroes (not empty areas, but single zeroes between nonzero bytes). There are many kbs of text also (several languages), inefficiently encoded too - a zero byte after each two symbols (must be related to 24-bit architecture of this cpu).

[Rufus]

Done, CD/CF series firmware is ~240k after stripping.

There is no protection to prevent reading the PIC firmware - sheesh.

I count about 30 20 character strings in the user interface in the manual, in 30 languages that would still only be about 17k of FLASH.

The 16 bit PIC tools use 32 bit hex file format to hold 24 bit words so every 4th byte will be zero. Constants in FLASH normally waste 8 bits of the 24 bit wide FLASH words although you can jump through some small hoops to avoid that.

Even if it is 240k less 25% I am amazed. I have two PIC24 designs, one with mono QVGA and touch screen the other with colour QVGA and a lot more buttons/inputs. Both have more graphics and far more to do than I can imagine controlling a soldering iron involves yet both use about 60% of the FLASH in a 128k part.

[alter Ratz]

A point about the "bloody software" and EMI-related lockups, etc - I don't know how this one works, but dead lockups are a pretty easy problem to get around... All you need is a small timeout circuit triggered repeatedly by the microcontroller. If the MCU locks, it times out and shuts the thing down.

Does it not have an integrated watchdog. Even the cheapest MCUs have that, and I suppose a MCU with an integrated DPD would be in a higher price range and most ceartainly has a watchdog.

[abyrvalg]

240k is after stripping that fourth always 00 byte. I didn't checked the protection fuse, got fws from update software. There is an empty address area at the beginning, must be some bootloader that isn't overwritten.
Also noticed interesting detail: all models fws mention same all kinds of possible tools (i.e. CD series knows about NP105 nano tweezers)