Variac to adjust soldering temperature
Michael Marmor
temperature of an inexpensive soldering iron. Does anyone know if
this is bad for the heater element in the iron?
I have seen circuits that will cycle 110V on and off at various
rates to control iron temperature. Is this a better method of
controlling the temperature than varying the voltage or is it
simply a less expensive way?
My iron is years old and needs replacing. Can anyone recommend an
iron? I am thinking about a good quality pencil type in the 30-40
watt range. Ungar? Weller?
73
Michael, AA2UJ
mma...@pluto.njcc.com
Rajiv Dewan
>I have been using a 10 amp Variac variable transformer to vary the
>temperature of an inexpensive soldering iron. Does anyone know if
>this is bad for the heater element in the iron?
>
>I have seen circuits that will cycle 110V on and off at various
>rates to control iron temperature. Is this a better method of
>controlling the temperature than varying the voltage or is it
>simply a less expensive way?
I have a Weller soldering station - it uses on/off control, keeping
the full voltage (28v ac?). It gets feedback about the tip temperature
from a thermocuple near the tip. The advantage of full voltage with
temperature feed back is that this method the tip heats up very quickly
when cooled such as by soldering. It adds to the effective "thermal mass".
It uses crossing detector swithches to minimize transients. It gets
Rajiv
aa2ui
D.C. Henderson
: I have been using a 10 amp Variac variable transformer to vary the
: temperature of an inexpensive soldering iron. Does anyone know if
: this is bad for the heater element in the iron?
:
: I have seen circuits that will cycle 110V on and off at various
: rates to control iron temperature. Is this a better method of
: controlling the temperature than varying the voltage or is it
: simply a less expensive way?
Mike
The variac will only cause your old iron to last even longer!!! The new
(and expensive) temperature controlled irons only serve to regulate the
temperature of the tip very precisely. In commercial soldering this
precise control serves to make consistent high quality solder joints and
minimize damage to todays very small circuit traces because of too much
heat. If you are doing a lot of very fine PC board and surface mount
component soldering you will "enjoy" one of the new irons.
Dave
N0DH/7
Spokane
n0...@comtch.iea.com
Mark Monninger
Michael Marmor <mma...@pluto.njcc.com> wrote:
>I have been using a 10 amp Variac variable transformer to vary the
>temperature of an inexpensive soldering iron. Does anyone know if
>this is bad for the heater element in the iron?
I use a lamp dimmer for the same purpose. The Handbook shows how to wire
it in the Construction Practices chapter. Works pretty well and probably
cheaper than a Variac. Of course, if you already have the Variac...
I doubt that it hurts the iron any. Matter of fact, I'd guess it would
help it, if anything.
73... Mark AA7TA
Ted Viens
>
>I have been using a 10 amp Variac variable transformer to vary the
>temperature of an inexpensive soldering iron. Does anyone know if
---snip---
>
>My iron is years old and needs replacing. Can anyone recommend an
>iron? I am thinking about a good quality pencil type in the 30-40
>watt range. Ungar? Weller?
>
>73
>Michael, AA2UJ
>mma...@pluto.njcc.com
>
Fair Radio Sales is selling a gov't surplus Weller kit for 70.00. These
are temperature controlled tips in the 500, 600, and 700 degree range.
All the parts are still currently available and a comparable kit today
would cost several hundred dollars. I don't have the phone number or
catalog number of the kit handy, but I sure recommend buying it.
Bye... Ted..
Tom Bruhns
: Fair Radio Sales is selling a gov't surplus Weller kit for 70.00. These
: are temperature controlled tips in the 500, 600, and 700 degree range.
: All the parts are still currently available and a comparable kit today
: would cost several hundred dollars. I don't have the phone number or
Hmmm. This seems high, unless they are pretty fancy kits. You can get a
new Weller WTCPT station from Newark for about $140. And with the move to
surface mount, a lot of old WTCP stations have come onto the surplus
market--assembly houses have scrapped them. The one I got 18 years ago is
still running fine, and I paid $5 or $10 for it at that time; since then
I've gotten a couple more for not more than $5. Things to look for in a
used one: the sleeve that holds the tip in should be removeable by hand
(not overtightened) and it should slide smoothly off the heating element.
If you can plug it in to try it, with a tip in it, after about one minute
it should melt solder, and in a couple minutes, it should start cycling:
you can hear it click occasionally. The magnetic thermal switch is
something that does go out, and it's important to check the one you get to
see if it's OK. A quicker test that should work OK too: turn it on with no
tip, while holding the end of the barrel near where the tip goes in. It
should not get hot. Insert a tip, and it should get noticably hot within
3 or 4 seconds. And inspect the cords, both power and the one to the iron.
They should be at least sound, if not clean. Another likely problem is a
break (usually intermittent and hard to find) in the cord to the handpiece,
and you pretty much have to take your chances with that. If you can get
them cheap enough, get two, one for spare parts ;-)
If you get one of these, NEVER tighten the sleeve with pliers; it need only
be finger tight. NEVER grab the sleeve in the middle with pliers: you
will pinch it down and it's very likely to start binding against the inner
barrel. You can get a very wide variety of tips for the Wellers (Newark
lists 18 shapes in three temperatures each--600F, 700F and 800F), and with
the right tip, the iron is fine for just about any normal ham soldering
smaller than what you'd use a torch on. You can even solder fine-pitch
surface mount ICs with them, if you are very steady and patient and know
the right tricks.
73, K7ITM
David Brodbeck
>Subject: Variac to adjust soldering temperature
>I have been using a 10 amp Variac variable transformer to vary the
>temperature of an inexpensive soldering iron. Does anyone know if
>this is bad for the heater element in the iron?
--> It shouldn't be, as long as you're using the Variac to decrease the
temperature, and not to increase it. In fact, running at a lower
temperature is probably easier on the iron.
_ _
__ _ _ _| | | | David Brodbeck Alma, MI
/ _` | | | | | | | Amateur Packet(AX.25): N8SRE@wb4vva.#nemi.mi.usa.na
| (_| | |_| | | | +------------------------------------------------------
\__, |\__,_|_|_| @ grex.cyberspace.org
|___/
Leon Heller
mma...@pluto.njcc.com "Michael Marmor" writes:
I've had an Ungar iron for several years and am quite pleased with it.
It doesn't *look* as well made as the Weller irons, but it works OK
Leon
--
Leon Heller | "Do not adjust your mind, there is
G1HSM | a fault in reality": on a wall
Email: le...@lfheller.demon.co.uk | many years ago in Oxford.
Phone: +44 (01734) 266679 |
Gary Coffman
>I have been using a 10 amp Variac variable transformer to vary the
>temperature of an inexpensive soldering iron. Does anyone know if
>this is bad for the heater element in the iron?
It's not necessarily bad for the heater, but it doesn't regulate
temperature except peripherally, it regulates wattage.
>I have seen circuits that will cycle 110V on and off at various
>rates to control iron temperature. Is this a better method of
>controlling the temperature than varying the voltage or is it
>simply a less expensive way?
This is a better method because it is a *closed loop* servo, even
if it is of bang-bang design. The Variac is an open loop power
controller while the thermostatic tip switch is an actual, if somewhat
crude, closed loop temperature controller.
The ideal soldering iron maintains a constant tip temperature at
all times, whether it is contacting a large heatsinking joint or
a delicate PC board trace. The required heat flow can vary depending
on the job, but the temperature needs to remain constant. The
best way to do this is with proportional closed loop control,
but the bang-bang method, coupled with adequate thermal mass in
the tip, will do an acceptable job if you have a range of tip
sizes to balance the thermal mass to the job at hand.
>My iron is years old and needs replacing. Can anyone recommend an
>iron? I am thinking about a good quality pencil type in the 30-40
>watt range. Ungar? Weller?
Weller is the defacto standard. Some manufacturers use more exotic
methods, one uses an RF heating element, but the good old Weller
WTCPN solder station will still serve for most amateur chores. If
you plan to do a lot of SMD work, a static hot air source will be
better, and an interesting portable one is the Weller Pyropen.
Temperature control is open loop, but you can frequently get away
with that when using the low thermal mass of air as your transfer
medium. Much better would be a closed loop Pace workstation. Couple
that with a B&L long working distance stereoscopic microscope, and
you're set for working on today's HTs. (You can get away with a
jeweller's loop, but you'll singe your nose from time to time,
voice of experience.)
Gary
--
Gary Coffman KE4ZV | You make it, | gatech!wa4mei!ke4zv!gary
Destructive Testing Systems | we break it. | emory!kd4nc!ke4zv!gary
534 Shannon Way | Guaranteed! | ga...@ke4zv.atl.ga.us
Lawrenceville, GA 30244 | |
Bill Kirkland
Anyone know of any sources for the Si8901 or SD8901 and
the SD5000?
Bill Kirkland
VE3JHU
Leon Heller
Pat Hawker, G3VA, in the Sept '93 issue of RadCom, mentions that
the Siliconix Si8901 has been replaced by the identical SD8901,
available from Calogic Corp. Siliconix's UK HQ is just round
the corner from where I work. I'm interested in these devices
so I'll make some enquiries and let you know what transpires.
Pat mentions that the SD5000 is "more widely available".
Siliconix here in the UK seems to have transmogrified into
Temic, if that helps.
Joe Landis - Systems & Network Mgr
I own two of these, I think they are the TCP-L model. They are 60 watt temp
controlled irons, with interchangable tips. With the small tips, you can do
delicate work on dips. Using my large chisel tip, they will easily solder
PL259's, copper flashing for 10Ghz horns, and hobby brass enclosures.
I got them from from a company that I used to work for when they went
under. I have considered selling the 2nd unit, but with my luck, the other
would die. I will NOT do without one of them. IMHO, they are the only way to
go.
I also own a 25w Ungar and of course an antique Weller Gun. I also own a big
old American Beauty (?). They all just gather dust. I use the 2 tempco Wellers
for everything.
Joe - AA3GN
--
Joe Landis - Systems and Network Manager - North American Drager - Telford, PA
lan...@nad.com | uupsi5!main03!landisj | Ax25: AA3GN@WA3TSW.#EPA.PA.USA.NOAM
michael silva
& Network Mgr) writes:
In the last few years I have really come to like the HAKO 926. It's got
variable temp. control, and some nice features, like ability to mount
iron on either side of holder, and a nice big sponge. I've seen them in
catalogs (MTM?) for about $90, and that was after I bought one for home
use at full retail!
Mike, KK6GM
Ted Viens
>
>Ted Viens (dr...@ix.netcom.com) wrote:
>
>: Fair Radio Sales is selling a gov't surplus Weller kit for 70.00. These
>: are temperature controlled tips in the 500, 600, and 700 degree range.
>: All the parts are still currently available and a comparable kit today
>: would cost several hundred dollars. I don't have the phone number or
>
>Hmmm. This seems high, unless they are pretty fancy kits. You can get a
----
I should get Fair Radio Sales to cut me a deal, still, I love gratuitously
promoting a good deal. This kit is a never used Hermetically sealed
(really) kit made ten or so years ago for the military. It includes about
20 parts. I will list only the Weller part numbers...
---
Large parts: WTCPK TCP-24G tip with EC234 heater BPS-24 SFG-1
DS-TCP desoldering tip with sleeve and DST4 tip.
Smaller parts:
Soldering Tips: PTA6 PTB6 PTC6 PTC7 PTL7 PTKX6 PTKX7 PTBCL5
Desoldering Tips: DST1 DST2 DST3 DST4 DST5 DST6
Specialty Tips: PTDTS5 DIT1 FPT1 < All mounted on sleeves.
---
I Don't have a Weller catalog or price list, But I feel sure that this is
more than the $140 station mentioned below.
I might as well become a slave to commerce and give the Fair Radio Sales
phone number: 419-227-6573 or 419-223-2196 the part number is #WTCPK.
I leave the rest of Tom's article because it is good advice...
---