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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
Hi and thanks for answer
No, I didn't.
a question:
How much current the T12 tips make at 450 degree?
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Messages - Ryan111
Hi and thanks for answer
No, I didn't.
a question:
How much current the T12 tips make at 450 degree?
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
The controller that I'm working on it. I'm using this project.
T12 tip.
Power supply is this.
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
When I apply PWM to the solder, there is some voltages if you touch it with your tongue and or back of your hands. Why? also I didn't connect the GND wire.
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
Build your controller for 9mV/512 degrees, set the temperature to 350 degrees, leave it there for 20-30 seconds, and everything will come to normal.[/quote]
Ok, Thanks.
I'm just worry for one thing. as you know my Op-Amp is ICL7650. I supply it to 8 and or 9v. with this gain and supply I afraid that it would hurt the ADC input. because of overload of Op-Amp(in fact, inductance of heater). or when heater is turned on and there is 24v on the input of Op-Amp, it would hurt the input ADC. Can both 1N4148 avoid such a problems?
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
How can I figure this problem out? Can I connect the tip dirctly to 24v for 20 or 30 to solve this problem?
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
Quote
T12 have thermocouple in series with the heater with a voltage of around 9mV at 450 degrees celsius...That's odd to me. because as you know, the temperature of boil water is 100c. I put the tip of the soldering iron in boil water and measured the output. that was 7mv. then if we assume that the output of the tip is linear thus the output for 450c should be (450*7)/100=31.5mv. Am I wrong?
Another question:
What's the usage of the resistor in the blue circle and that part in the red square?
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
Is there any global supplier available at you place?[/quote]
The land of the Cyrus the Great(I mean Iran :) )
Not for all countries! for instance the Digikey even blocked its website for us. because of sanctions (wink). on the other hand, useing the card of a financial services corporation like MasterCard isn't simple in my country(again blocking). nowadays, ordering from china is a common way, here (we can order some components from aliexperess and etc via some trick :) ). I don't know when we can get rid of these F**king sanctions.
anyway, ICL7650 is on the way! :) I have ordered it from a local market.
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
Exactly!
Also I can order it from china but this approach would be too expensive for me or at least ordering a component isn't wisely.
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
I think I have to make up this station with another Op-Amp. How about one of these: OP37, ICL7650S, OP177FPZ, OPA2340(this is a rail to tail I/O) which one of these can help me to get a reasonable accuracy? which one would be better?
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
Ok, I changed the server of the images. please check out my last post, again.
[quote author="sparkybg"]
1. You don't need a megasamle ADC reading.
2. You will have to wait a little (500uS foe example) after you stop the power to the iron before you read the voltage. There is inductive peak after you turn the power off. The heater has inductance.
3. You don't have to worry about picofarads. Controling the iron is pretty slow process. On my new version, I am using 10 nanofarad caps to filter the signal and it is still fast enough to stabilize the opamp output in 150 micriseconds.[/quote]
Thanks
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
For supply I want to use this and for 5v parts I want to use this buck module and for 3v3 (actually for MCU) just use a AMS1117. AMS1117 can get 5v from buck module. is everything ok, so far?
ok let's talk about AD8572ARZ.
if you take a look in the datasheet, you will see this in page 29:
In your opinion is this circuit good for soldering iron?(in other word for T12 tips) also I think I have to change somethings for my MCU(because it's a 3v3 MCU and probably should change the gain of the Op-Amp).
in page 19, something about overshoot has been brought up (CAPACITIVE LOAD DRIVE) and also POWER-UP BEHAVIOR:
This is my ADC characteristics:
Then I think there is not any worry about overshoot(because of the capacitance of the ADC. also the capacitance of each I/O pin of my MCU is 5pf. I cannot measure the capacitance of track on PCB now ). although I guss I have to make a delay before each reading the Op-Amp output (because the clock rate of my MCU(72MHz) and the speed of the ADC and settle time for the Op-Amp ).The ADC on my MCU is a 12bit :) look at this:
1 million sample per second! and operat in 14MHz! ha ha!
please clear me if something isn't correct.
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
alone "rail to rail" "auto zero" Op-Amp that is availble to me. please ignore the price. if it's ok for this job then just show me green light!(I mean tell me to start to design my circuit by this AD8572ARZ)
Personally I think it's ok and there is no problem. Am I right? please check out the datasheet.
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
What's your opinion about LM358? and a circuit like in this page:
http://www.bristolwatch.com/ele/thermal ... lifier.htm
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
[/quote]
I used a 90W adapter. The T12 tips are 70W, but it is better to give some margin.
[quote author="Ryan111"]2- My MCU is a 3.3v (unlike your MCU that is a 5v) then I have a problem. there is no problem for transistors (I can bias them) but I don't know how and what should I chenge for Op-Amps?[/quote]
You can use 3.3V to drive the transistors without problem, you don't have to change anything or at least reduce a little the R11.
In the op-amp you only have to adjust de gain (P1) to ensure that the output voltage is always below than 3.3V[/quote]
Thanks for answer and sorry for delay.
unfortunately Microchip Op-Amps ain't available in my country(especially auto-zero). I'm searching to find a suitable Op-Amp for this job. the sad point about me is that I'm not very good familiar with Op-Amps. due to my MCU(that is a 3v3) and 9mV output from iron I think I have to find an Op-Amp with around 366 gain(am I right?). currently I have these Op-Amp at home: LM318N, OP07CP, CA3130E, LM324N
could I figure out this problem by one of this Op-Amps? how about an AD620? what type of Op-Amps are suitable for this job? what factors should I consider for choosing an Op-Amp?
sorry for simple questions.
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Project logs / Re: My HAKKO classic and T12/T15 soldering controller
http://http://dangerousprototypes.com/forum/viewtopic.php?f=56&t=5264&start=180#p58264
but I have several question.
1- you said that you used a 24V dc laptop power supply but how much current? Is 3A enough?(70/24~3A)
2- My MCU is a 3.3v (unlike your MCU that is a 5v) then I have a problem. there is no problem for transistors (I can bias them) but I don't know how and what should I chenge for Op-Amps?