I recently bourght the xytronic LF-389D soldering station from Rapid electronics for about £67. after unboxing and turning on i was imediatly very impressed the quality is just amazing and it is light weight. I took Dave jones aproach of not turning it on before taking it apart, so i opened it up and had a look inside. the quality of the build is briliant the only probel is the caps are a bit cheep but other than that the quality is very good. i dscoverd that it is so light weight because there is no large mains transfromer just a tiny low power pcb mount one whitch looks like it is just powering the digital stuff. there is a big filter on the imput probably for conducted EMC complience i was suprosed that they put so much effort in to doing this.
temp range: 150c to 480c
power: 60W
the bad things about this soldering station are:
- no spaid tip available
- you have to opent the unit to replace the iron although this may not be such a bad thing as it does stop the conection from comming lose during use.
- the heating indicator is not that great it is hard to see and just a bit anoying as it is part of the 7 segment display.
question: how des this work there are no visable thermo couple or thermistor wires coming from the iron its self. the iron is clearly mains powerd as there is not a big enough transformer to power it. it apeers that it reaches the corect temparture as i tested it whith the thermo couple on my Etech EX330 DMM.
So let us know how it works after using it.
The outside looks indentically as my LF1600. The LF 1600 is taller though due to usage of conventional mains transformer (looks like you have a switcher there, right?).
You could try to reverse engineer the circuit, but I think a quite reasonable solution would be to measure the resistance of the heating element and determine temperature based on that.
And please check the caps (as I noted in your other thread). Mine had shitty CapXons inside.
I could buy a cheep £10 iron to replace caps, and the iron does work incredibly well, I have tried soldering 0805 resistors with it and it works a treat. I will post some more detailed teardown photos later.
How fast does it heat up? And how is the thermal capacity?
It heats up very fast (aprox 1min) and has a good thermal capacity but I have not yet tested it on anything really big but it seems to beet a large bit of metal (eg a quick disconnect) rather fast
Curious to see the underside of the board, especially how Primary and Secondary is. Also closeup birdseye view of topside of board
@Poorchava that's not a SMPS (Switcher)
The outside looks indentically as my LF1600.
I had to turn around and check my LF1600 when I saw the pic. Looks identical. I have spade tips for mine, and really like it.
I also have the Autotemp 379, and its never let me down either.
They make several models that are identical but may have minor differences such as power the one I have was the cheapest
i have opened the unit up further and taken the PCB out fully i have added some photos.
- I am pleesed to see adequat creapage and clearence between mains traces.
- the transformere is a center tapped primary (i think) it is clearly only powering the digital stuff
- I coudnt work out what the main IC is as i couldnt read it.It is probably a basic micro controller but i dont know which one.
I have these questions:
-is the large resistor a current shunt to measure the curent across the element and therfore the resistance?
-are these caps a cheep brand?
(i apologise for the quality of the photos as i took them on my phone)
Just a quick update. I was doing some desoldering work of power supply parts most of whitch had large amounts of copper the iron did seem to struggle a bit to melt the solder I suppose it is to be expected whith an 80w iron
Those caps don't seem to be of the best (Nichicon, Nippon chemicon, Panasonic, etc)
The resistors seem adequate (0.25w or 0.5w rated while they could have used smaller ones).
Capacitors are probably OK for the application, but they're not great (not in the same class as Japanese brands like Nichicon, Rubycon etc or Panasonic which are made in Malaysia but parent company is Japanese).
Tocon isn't as crap as the no-name chinese capacitors, let's say they're a bit better. As far as I know, the company is taiwanese :
http://www.tocon.com.tw/cap.html
Yea, they are an OK brand. I have repaired broken equipment with those though, but it was mainly the manufacturer being a tight ass and not using properly rated caps.
Old thread I know, but I have an older model, the 379, and I believe it takes the same tips as the LF-389D. If it doesn't, the same sources definitely has tips for the LF-389D - in the US, Howard Electronic Instruments, which is where I bought my 379 some 7-8 years ago. I recently bought tips for mine, which are still available (as are heater elements), but I only wanted some in a different size, as the original one that came with it is still good.
I don;t know about dealers in other countries, but there definitely are a wide variety of tips available for the LF-389.
In case anyone wonders, tips for FX8801 FX888 is compatible with LF-389D. e.g. Hakko T-series and older 900m as well as the Persder 10pcs set sold on Amazon. I would recommend Hakko tip T18-C1 for smd soldering, I use it for almost all my soldering using this station and it works great. Genuine Hakko tips can be found on eBay and shipped from Japan. LF-389D is a nice soldering station. The Persder tips works well too.