This is what I know about the Weller five-pin soldering iron system. As far as I can tell, they all operate at 24V with bang-bang controls. The EC1002 is one of many power supplies designed to operate with the EC1201A handset. The EC1201P handset is the same thing as the EC1201A just with a nonconductive plastic handle instead of a conductive plastic. The TC201T seems to be the same. These handsets have two gold-plated pins and three tin-plated ones. The gold-plated ones go to the thermal sensor and they should read about 21-27 ohms between them if the sensor is good. One of the tin-plated ones is ground and is connected to the metal case. The other two are the heating element and they should have 12-14 ohms between them. Some time around 1998 they changed the EC1201A from a unit that had a heating element with leads to a newer design that used pins. The newer ones with pins take an EC234 replacement element. The older ones with leads require a TC208 replacement element, combined with a BA60 adaptor to deal with the flared barrel. The EC229 temperature sensor will fit both the new and the old ones. Cord assembly C223 is supposed to fit all of these. Scott Dorsey, 2010 -------- Additional Note: Weller replacement tips designed for the TCP/TCP201 series irons that use curie point control can be used with the EC1201 irons by drilling a #34 hole 5/8" deep in the back to accomodate the sensor. Although the hole does not have to be precisely centered, it is easier to insert if it is. If drilled on a lathe, the #34 bit is rather flimsy and hard to center so it can help to use a 5/8" bit to just make a centering dimple for the hole first. Note that the tip is a very gummy copper alloy that clogs the drill easily. Scott Dorsey, 2017. --------- Soldapulit Note: The Soldapulit uses one rubber O-ring, which looks to be loose when the piston is removed from the cylinder. It becomes tight in operation. Edsyn part number ODS31 is marked as "O-Ring, ID: 0.674 in (17.12mm), W: 0.103 in. (2.62mm)." However, the actual rings provided appear to be slightly different and appear to be standard #13 O-rings. Hardware store #13 rings seem to work just fine as replacements. Scott Dorsey, 2017. --------- The Weller WES51 is the new replacement for the EC1201P it seems. It is pin-compatible and will take the same tips and power supplies, but the handle is lighter and does not balance as nicely. Scott Dorsey, 2018. ----------- The power transformer in the Weller EC1002S power supply is Weller part TR234, which is te.com part 400-01AW18CD827. This is a 120V primary, 24V secondary, 50VA, CD side termination, and the 827 is the customer number. It was clearly a custom item. Scott Dorsey, 2019.