I've seen a number of different designs for sleep sensor circuits that are contact-based and seemingly detect when protective earth / chassis ground is connected through the handle. I'm attaching the schematic for the particular sensor board I happen to have received with my unisolder PCBs as an example.
I'm curious what the functional principle of those sensor circuits is - i.e. how do they detect whether or not protective earth is connected to the holder?
I find the schematic of the sensor I have particularly confusing because it seems to effectively leave the logical input to the inverter (implemented with a quad-NOR) floating when J1 isn't pulled down to GND so that D1 is in reverse-bias.
That sensor, as well as other's I've seen, also seem to reference the controller's supply to earth ground through R1 when the handle is present in the holder. Is that intentional and safe to do? So far my understanding was that the unisolder's power-supply should be floating and not referenced to earth.
In my unisolder build I'm using an E-I transformer to step down 120VAC mains to 24VAC to supply the PCB. Based on the available documentation it looks to me like the secondary of the transformer is intended to be floating, though I've not seen that stated explicitly anywhere.
Is that indeed the intention, or should the secondary be ground-referenced? If it should be floating, what'd be the failure mode to expect if isolation between primary and secondary was to fail for some reason?
Use an 8 pin socket and connecor, and follow the connection schematics on page 1, even if you find them not logical. They work. All irons can be connected on the same 8 pin receptacle. It is true that the T210 and T245 are connected differently electrically, but I assure you this is correct.
that's why most users change the original connector with GX16-8p or GX20-8p as it is into docs from 1st page
I appreciate both of your responses. The bit of information I was missing was that the intention is for the JCB-style connectors to be replaced with alternative ones that are wired up to be electrically compatible while the original ones are not. That clears up my question and the documentation makes sense to me now taking that into account.
That is your job to connect them propper way based on the info from the 1 page !!!
The information from page 1 that you're referring to again to me still seems to indicate that it's not possible to wire up a receiving connector for C245/C210 handles that'll transparently accept either style of handle based on the pinout differences between them, and I'm still looking to confirm whether or not my understanding of that is correct.
To me the documentation seems to only describe how to connect either one style of handle or the other, but not both in such a way that either can be plugged in and just work transparently.
Use the info from the first page and that picture published somewhere in that forum
That's the information I was describing in my question. Based on that information it looks to me like the pinout is not compatible between C245 and C210 handles, and that it's not possible to use both types of handles interchangeably with the same station after installing the instrument-identification resistors in the handles.
Is my understanding of that situation correct? I found it kind of surprising as it makes the instrument-identification feature seemingly useless.
I'm currently building my first unisolder station and am somewhat confused by how instrument identification is intended to work. Specifically, I'd like to be able to connect either a C245-style or a C210-style handle to the station depending on the soldering-task.
Initially I thought that all I'd have to do is place the appropriate pair of resistors in both of the handles to allow the station to identify them, but when starting to put things together I noticed that there's some differences in the documented pinouts for those two different kinds of handles. In particular the heater positive terminal (red wire) on C245 handles is suggested to be connected to Vout1-, whereas the documentation for C210-style handles suggests connecting that same pin it to Vout1+ instead.
Does that imply that I can't wire up a single connector that'd accept either type of handle and is able to identify the different instruments based on their resistors? Why does polarity even matter for what I thought was just a resistive heating-element?
