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Topic: My HAKKO classic and T12/T15 soldering controller (Read 324717 times) previous topic - next topic

Re: My HAKKO classic and T12/T15 soldering controller

Reply #105 –
[quote author="jry"][quote author="sparkybg"]Thank you. It appears that they are really treating each tip completely separate from another one.[/quote]

So it means two separate channels (secondaries, mosfets, opamps, MCU) even for tweezers controller.[/quote]

Yes, or at least I thing so.

Re: My HAKKO classic and T12/T15 soldering controller

Reply #106 –
[quote author="sparkybg"]Now I measure it between C2 and C3 on my controller, in order to be able to connect earth to C1.[/quote]

Is TC voltage between C2 and C3 also present on heated standalone tip, disconnected from handle?

Re: My HAKKO classic and T12/T15 soldering controller

Reply #107 –
[quote author="jry"][quote author="sparkybg"]Thank you. It appears that they are really treating each tip completely separate from another one.[/quote]

So it means two separate channels (secondaries, mosfets, opamps, MCU) even for tweezers controller.[/quote]

I guess there is an reason that the tweezer cannot be used for the CD-2BB/2BC, but then again you have CP-2C...

Re: My HAKKO classic and T12/T15 soldering controller

Reply #108 –
[quote author="jry"]
Is TC voltage between C2 and C3 also present on heated standalone tip, disconnected from handle?[/quote]

Yes, it is. You can measure it yourself.
Get a lighter, put your multimeter on "mV DC", attach it to C1 and C3 terminals of C245, and heat up the tip with lighter. You will see a rising voltage between C1 and C3, which will be around 4mV per 200 degrees celsius. You will see the same voltage on C2 and C3.

Re: My HAKKO classic and T12/T15 soldering controller

Reply #109 –
Strange. In this case I don't see where the thermocouple could be.

I will receive my JBC tips during a few days - still waiting.

Re: My HAKKO classic and T12/T15 soldering controller

Reply #110 –
[quote author="jry"]Strange. In this case I don't see where the thermocouple could be.
[/quote]

A thermocouple is a loop of two dissimilar metals. With reference to the section photograph on the previous page there is very little thermocouple between C1 and C2 terminals they are probably both stainless steel. The heater element is dissimilar but there is little temperature difference across it - what difference there is when you heat the tip might account for the observed slight thermocouple effect between C1 and C2.

The dissimilar metal in the cartridge has to be the centre rod C3. What is it is I have no idea, the thermocouple is likely stainless steel and this 'something'. The cold junction for this thermocouple is the contacts in the hand piece and the hand piece does warm up especially with heavy use so it is a significant source of temperature error. They might be able to make an estimate of hand piece warming and roughly compensate in software.

Re: My HAKKO classic and T12/T15 soldering controller

Reply #111 –
[quote author="sparkybg"][quote author="jry"]So it means two separate channels (secondaries, mosfets, opamps, MCU) even for tweezers controller.[/quote]

Yes, or at least I thing so.[/quote]

Possible solution for PA120 Micro Tweezers would drive and measure only one tip in one time (25Hz)? Disconnect other tip C2(-) and C3(+) connections for this period. With 100VA transformer you would need limit tip power anyway.

Re: My HAKKO classic and T12/T15 soldering controller

Reply #112 –
A guy pointed me to this thread:
http://www.eevblog.com/forum/testgear/j ... /msg376294

It is just another investigation.

I think, maybe there are two thermocouples. One between C1 and C3 and one between C2 and C3. Otherwise I cannot figure out how it is possible to have same TC voltage on C1-C3 and C2-C3. Maybe  the outer shell and the middle (C2) sleeve are from same material. The heater also is from this same material, and the C3 (the pin) is from dissimilar material from all other.

If this is the case, then driving 2 tips is easy - you put common ground on outer shell, common "-" on the pin and separate "+" on the sleeve. And the TC voltage will be negative in respect to common "-" this way, so we have to use inverting amplifier to read it. Tonight I will try what happens with C2-C3 TC voltage when C1-C3 are short-circuited. If the C2-C3 voltage stays the same when C1-C3 are connected together, then this might be the case (2 thermocouples).

Re: My HAKKO classic and T12/T15 soldering controller

Reply #113 –
Maybe that's the reason its so difficult to measure the resistanse?, I have two fluke's, 87-v and 289, and the numbers are just rolling, but on my Agilent 34461A, it's easier to get the almost correct resistance, still rolling, but easier to controll.

It's difficult to do measurements inside the connectors, as they are heatshrinked, should have made an breakout with these hirose connectors so one could see what's going on when using them, the reference I got earlier to measure somewhere on the flatcable inside, is not very appealing :)

Re: My HAKKO classic and T12/T15 soldering controller

Reply #115 –
Just as I thought. They are using USB-RS232 + isolator for connection to the outer world. :)

As for resistance - I didn't had any problem measuring it. It is hard to measure if the tip is warm, but then, on Fluke 289 (and perhaps 87-V) you should have a function to measure the resistance in the presence of offset voltage. My Agilent U1272A has it, and it is more or less an equivalent to Fluke 87. With this function it can measure the resistance correctly even when the tip is hot and with several millivolts on the thermocouple. My cheap chinese miltimeter also measures the resistance of the cold tip without any problem. I don't know where your problems are coming from.

Re: My HAKKO classic and T12/T15 soldering controller

Reply #116 –
Breakout would be great also for waveform test (if they are driving tips with sine wave or half/full rectified).

Re: My HAKKO classic and T12/T15 soldering controller

Reply #117 –
[quote author="sparkybg"]Just as I thought. They are using USB-RS232 + isolator for connection to the outer world. :)

As for resistance - I didn't had any problem measuring it. It is hard to measure if the tip is warm, but then, on Fluke 289 (and perhaps 87-V) you should have a function to measure the resistance in the presence of offset voltage. My Agilent U1272A has it, and it is more or less an equivalent to Fluke 87. With this function it can measure the resistance correctly even when the tip is hot and with several millivolts on the thermocouple. My cheap chinese miltimeter also measures the resistance of the cold tip without any problem. I don't know where your problems are coming from.[/quote]

Is that a function you have to activate?, I must admit that all instruments are new, so possible there are somethings I didn't check.
Probably I should get out my old Fluke 75

Re: My HAKKO classic and T12/T15 soldering controller

Reply #118 –
On my multimeter there is a button to activate it. It is called "smart ohm" or something similar (I am at work now and cannot see).

I suspect that it must be activated by the user on Fluke too if it has it. I don't know if 87 has it, but I think 287 must have it. I don't know how it is called on Fluke.

Re: My HAKKO classic and T12/T15 soldering controller

Reply #119 –
[quote author="sparkybg"]If this is the case, then driving 2 tips is easy - you put common ground on outer shell, common "-" on the pin and separate "+" on the sleeve. And the TC voltage will be negative in respect to common "-" this way, so we have to use inverting amplifier to read it. Tonight I will try what happens with C2-C3 TC voltage when C1-C3 are short-circuited. If the C2-C3 voltage stays the same when C1-C3 are connected together, then this might be the case (2 thermocouples).[/quote]

Do you mean this way?
Edit: updated scheme.