ZD-985 desoldering station cross-compatibility - Page 1
Forum section: electronics / general

author: wblock
author_rank: Regular Contributor
timestamp: November 12, 2015, 01:30:40 am
content: Can anyone give the heater and thermocouple resistance of the ZD-985 desoldering gun? They appear to be clones of Hakko stuff, but which one?According to Hakko, the 817 has a 9 ohm heating element (pins 1 and 3) and the "sensor" is 54 ohms at 73F (pins 2 and 4). Of course, the ZD-985 might use different pins and possibly a reversed connector. The much older 802 gun had a 2-4 ohm heating element (at 73F, appears to be on pins 1 and 2), and the parts diagram oddly omits mentioning or showing a sensor. The wiring diagram suggests it is on pin 3, maybe sharing a common wire with the heater.Are any of the parts compatible, like tips or filters?In other words, can a cheap ZD-985 gun be adapted for use with a Hakko desoldering station? Can a Hakko gun or parts be used on the ZD-985? Or maybe other brands? The used market has many, many desoldering station controllers with no pen or gun.

author: mich41
author_rank: Regular Contributor
timestamp: November 12, 2015, 08:34:52 am
content: Not that I can answer your question (I don't own this particular clone), but......the notion of "thermocouple resistance" just doesn't make sense. Thermocouples are temperature-varyingvoltage sources(with very low series resistance) and temperature-varying resistors are calledthermistors.Both kinds of sensors are used in various soldering stations and both are used in various Hakko clones. In fact, even clones of the single Hakko 936 model can use either and hence aren't always compatible.Exact information about particular models can often be found on the web.

author: krivx
author_rank: Frequent Contributor
timestamp: November 12, 2015, 08:47:05 am
content: These units employ a control loop anyway, so some variation in parts may not even matter once you calibrate them.I have a ZD985, I can take a look at it but I'm not sure if it will be useful to you.

author: wblock
author_rank: Regular Contributor
timestamp: November 12, 2015, 01:06:29 pm
content: Quote from: mich41 on November 12, 2015, 08:34:52 amRight, I had changed that to "sensor" in later sentences because Hakko never really says exactly what they use, but missed the assumption in that first sentence. For the 817, they list the resistance values for both the heater and sensor, but give no other details.

author: wblock
author_rank: Regular Contributor
timestamp: November 12, 2015, 01:29:57 pm
content: Quote from: krivx on November 12, 2015, 08:47:05 amTrue. And when it gets right down to it, many desoldering (and soldering) stations are a 24V transformer with variations on switching circuitry and a small microcontroller running that feedback loop. That microcontroller can be replaced or reprogrammed, although then it becomes a development project. Which, admittedly, might be fun.QuoteIf not for me, maybe for others looking for parts and compatibility.

author: Rasz
author_rank: Super Contributor
timestamp: November 14, 2015, 05:52:06 pm
content: 985 gun looks the same as 915/917 oneno idea of the pinout, I scored $10 auoye pump few months ago, but havent got around to building desoldering gun yet

author: wblock
author_rank: Regular Contributor
timestamp: November 14, 2015, 07:24:42 pm
content: The part number for the gun is ZD-552. Some interesting stuff found on a Greek forum, including a connector pinout, analog controller circuit schematic, and PC board pattern:http://www.hlektronika.gr/forum/showthread.php?t=70303

author: Rasz
author_rank: Super Contributor
timestamp: November 14, 2015, 08:21:15 pm
content: PTC it is then88-552A to be exact915/917 has different socket, one less pin

author: wblock
author_rank: Regular Contributor
timestamp: November 15, 2015, 12:49:45 am
content: Quote from: Rasz on November 14, 2015, 08:21:15 pmThe 915 might have been a clone of the earlier Hakko 470 and 802 gun (four-pin), while the ZD-985 is a clone of the 472 and 817 gun.The Zhongdi site claims that the latest version of the ZD-985 has seven pins, the new one providing a sleep mode:http://www.china-zhongdi.com/manager/upload/pic/201517223416probigpic.jpgI say "might have been" because that also shows the ZD-915 now uses the six-pin gun.