Adding a light to a WTCP Soldering Station - Page 1
Forum section: electronics / beginners

author: Adler
author_rank: Regular Contributor
timestamp: March 20, 2013, 11:55:04 pm
content: I have a very old soldering station. One of these days Ill get a true variable temperature station but until then I have a Weller WTCP. It regulates temperature based on the tip. They sell 600, 700, and 800 degree tips and they have a pretty cool magnetic switch in them.My issue with this unit is that there is no light to indicate power. Having left it on over the weekend (its miraculously fine) I'd like to add one.I cracked it open and was surprised to find virtually nothing in it. literally a switch, a fuse, and a strange transformer.Here is the the circuit (in paint)Where would be the best place for a light?I was thinking I could add an AC light after the fuse or a DC light after the transformer... But I want the most robust solution.On another note. I've never seen a transformer like this before. Its like a giant rolled up sheet of metal. What's this called?

author: mariush
author_rank: Super Contributor
timestamp: March 21, 2013, 01:37:04 am
content: That's a R-Core transformer, some Japanese guys invented them :http://www.custommag.com/products/r-core.shtmlAs for the light... you could simply get one of those crappy usb chargers (or some phone charger), take it out of the case and connect it after the switch, so when you flip the switch, you have a convenient 5v inside for whatever you want, including a led which you can just limit using a resistor.

author: DavidDLC
author_rank: Frequent Contributor
timestamp: March 21, 2013, 02:04:33 am
content: You can also connect a LED and a resistor direct to the A.C. , just need to make the correct calculations.David.

author: pickle9000
author_rank: Super Contributor
timestamp: March 21, 2013, 02:42:32 am
content: Get an old fashioned neon indicator, 120vac (already has the resistor in the case) you could swipe one out of an old washing machine but a new panel mount one can be had for under 3 bucks (less for the crusty ebay ones).

author: Farley
author_rank: Regular Contributor
timestamp: March 21, 2013, 02:52:37 am
content: Some of the WTCP images I see on google appear to have an illuminated switch. My WTCPT has one that lights red when it is powered on. Would it be possible to fit a replacement illuminated switch into your unit?

author: notsob
author_rank: Frequent Contributor
timestamp: March 21, 2013, 02:59:20 am
content: Go with an illuminated switch, if you can find a suitable one, or fit a neon across mains switch on secondary sideSomething likehttp://australia.rs-online.com/web/p/neon-indicator-lamps/0104777/

author: Adler
author_rank: Regular Contributor
timestamp: March 21, 2013, 03:04:52 am
content: I actually have a few neon 125v indicators in my parts box.I like the idea of an illuminated switch, I'd rather avoid drilling a hole in the case. Ill see if I have one of those too. I vagely remember having one...

author: Adler
author_rank: Regular Contributor
timestamp: March 21, 2013, 03:09:14 am
content: Looks like I have a couple of these...http://www.aliexpress.com/item/Rocker-Switch-16A-250VAC-SPST-3PIN-ON-OFF-220V-illuminated/446179337.htmlThey are a little too long. Ill look into getting a perfect sized one. A Weller switch would be ideal.

author: Adler
author_rank: Regular Contributor
timestamp: March 21, 2013, 04:34:24 pm
content: Now I'm seriously considering building one of these. Kill two birds with one stone...http://spritesmods.com/?art=wtcpled

author: SeanB
author_rank: Super Contributor
timestamp: March 21, 2013, 05:39:48 pm
content: Simpler way to do it is to take a bicolour LED ( 2 lead type) and wire across secondary with a 2k2 resistor. Then take a reed switch ( easiest to find as part of an alarm system as a door/window switch along with a magnet) and remove the reed from the case ( carefully) and wind around 50 turns of 0.5mm copper wire around the reed. Place this in series with the lead to the iron so as to sense the heater turning on. Take the reed wires and place a diode across them, and put in series with the wire to the LED. Thus if heater is on it is orange and if it is off it is green. If it is orange and red turn the diode around. I have done similar to make blown bulb detection for my car, used on the trailer connection so as to easily check for poor connections or blown bulbs. Worked quite well.