Temperature controlled soldering iron

[fingaz]

Hi,

I recently saw a circuit that controls the temperature of a standard soldering iron by controlling the length of time the iron is "turned on". (ie it switches on for say 30 sec, then off for 10) I have lost the circuit diagram and wondered if anyone has seen something similar, or knows where i can download it again.

Please, please, please, and help would be appreciated.

 

[Nigel Goodwin]

You could do it with a 555 and a triac, but it's a really poor way to try and alter the temperature - I wouldn't suggest it's even worth trying!.

BTW, where abouts in Derbyshire are you?, I live not far from junction 29 on the M1.

 

[HarveyH42]

This sound like the same sort of circuit used to control the speed of ceiling fans, dim lights, or control the speed of power tools. Might look it to these.

 

[bbarney]

try this link
http://members.shaw.ca/roma/iron.html

 

[philba]

wow, now that is one complicated way to get that effect. toss all the logic there and replace with a 555.

While I agree that it's a poor way to do it, it could be somewhat effective if your iron is of high enough wattage that it can heat well above the temperature you want. Otherwise, it's a complete waste of time. Most temp controlled irons use a sensing technique (heater resistance, I believe) to determine how long to heat for. This is particularly noticable during heat-up. If you go this route, you might want to consider using a second timer to over-ride the first for, say, 30 seconds of heat up.

And for the compulsory "do it with a PIC" comment. It wouldn't be that hard to use a microcontroller to sense the current through the heater to determine it's temperature and decide how long to apply the heat pulse. it would take some calibration (of the tip temperature). this won't be as good as a controlled soldering iron unless the heater is very near the tip, though. Usually, cheap irons aren't built like this.

edit: oh, yeah. after all that, I suggest you just go buy a decent soldering station - you can get ok ones for around $50 usd.

 

[dknguyen]

Yeah, the Goot PX-201 is a good one (if you want a temperature adjustable iron that is not a station).

 

[fingaz]

Thanks for all the help, it's much appreciated.

btw, Nigel, I live near Alfreton.

 

[HiTech]

edit: oh, yeah. after all that, I suggest you just go buy a decent soldering station - you can get ok ones for around $50 usd.

Uh hello? Did you bump your head on the way in here? Used stations are selling for $50.... that is for the well known brands. New, they sell for well above $80 and up. I just might build me that circuit shown in that link. I have just the pencil and station to house that circuit in.

 

[philba]

Uh hello? Did you bump your head on the way in here? Used stations are selling for $50.... that is for the well known brands. New, they sell for well above $80 and up. I just might build me that circuit shown in that link. I have just the pencil and station to house that circuit in.

Maybe you should lose the rude attitude.

Did I say "new"? No. so not only did you unnecessarily piss on me but you actually validated my point. which makes me wonder if you were just looking for a reason to be a jerk.

 

[Tarsil]

This kind of circuit isn't very eficient. The actual temp of the soldering iron varyes a lot. A much more acurate way is to use a thermal sensor (thermistor, semiconductor junction etc.) and a opamp or comp so the power is turned of when a certain temp is exceeded. Another way is to measure the tip's resistance.
Also measuring the voltage drop on the resistance used to heat the tip is an idea.

 

[evandude]

Uh hello? Did you bump your head on the way in here? Used stations are selling for $50.... that is for the well known brands. New, they sell for well above $80 and up. I just might build me that circuit shown in that link. I have just the pencil and station to house that circuit in.

say what you will, but I've been using a $35 temperature-controlled station for years now and it's treated me very well...
https://www.circuitspecialists.com/prod.itml/icOid/7307
I've got the full schematic of it and there's nothing more complicated to it than some analog circuitry with op-amps, and some triacs, so if anything ever goes wrong it shouldn't be hard to fix it myself.

and along the lines of the original post... using a commonly available lamp dimmer with a soldering iron:
**broken link removed**
definitely not a great method...

 

[HiTech]

Maybe you should lose the rude attitude.

Did I say "new"? No. so not only did you unnecessarily piss on me but you actually validated my point. which makes me wonder if you were just looking for a reason to be a jerk.

Ok then I'll lie to you then. Yes, one can purchase soldering stations for under $50. Be happy and content. You get what you pay for.... a very true statement.

Truth mode on:
Junk stations sell for cheap prices. They don't last all that long, esp. for the professional technician that uses it 40 hrs./wk. Tip variety is practically nil, and so are replacement heaters, etc. For the weekend hobbyist, yes, I agree that a $50 station is "probably" adequate. Otherwise they are a waste of $$. My Weller digital station bit the dust after a faithful performance of 6 years --- over 2000hrs./yr. for 6 years. And even then, only the control circuitry was too far gone for servicing. So, I bypassed that and still kept the thing going for another 10 years. Just last week it totally failed, heater element and transformer. Guess what? It's been replaced with another one just like it.

 

[penoy_balut]

Hi,

I recently saw a circuit that controls the temperature of a standard soldering iron by controlling the length of time the iron is "turned on". (ie it switches on for say 30 sec, then off for 10) I have lost the circuit diagram and wondered if anyone has seen something similar, or knows where i can download it again.

Please, please, please, and help would be appreciated.

lamp dimmers can do the job

 

[fingaz]

hey people, can we calm down a bit plz. . .
there's no need to get all worked up about it. . .

JUST CHILL

and thanks for all the help and suggestions

 

[HiTech]

do you see what you started?

 

[philba]

do you see what you started?

ahem, who started what???

 

[fingaz]

Yeeehaaa!!!

 

[HiTech]

It's Yee-Haw you cowboy wannabe!

 

[fingaz]

well, Yee-Haw. . . now i'm a proper cowboy too ;-)

 

[Nigel Goodwin]

We lynch cowboys in Derbyshire!