Modification of the JBC HD-2B soldering station to work with 24V and 48V tips

[URI]

I acquired a surplus JBC HD-2B soldering station with T470A handle, some tips and original JBC stand.

I'd like to share my modification of my JBC HD-2B soldering station to work with 24V and 48V tips.

There are two types of cartridges (JBC-tip) I want to be able to use with my HD-2B:
24V-types (C245-cartridges) and 48V-types (C470-cartridges)

Nice thing is that the T470 handle accepts C245 and C470 types of cartridges.
Problem is that the HD-2B only works with 48V.

Only newer HD-Stations have an automatic 24V/48V switching depending on the type of cartrigde.

The two types differ in their heater resistance:
C245: ~2,4Ohm at 22°C
C470: ~7,4Ohm at 22°C

JBC designed the HD-2B very modification-friendly: The transformer has two 23,5V/50Hz secondary windings switched in series to form the 47V heater supply.
The modification is simple: I just modified the connection between transformer and mainboard to switch between serial and parallel switching of the secondary windings of the heater supply.
The connection of the two secondary 23,5V windings is made on the PCB of the mainboard. This connector has to stay connected to 23,5V, otherwise the station doesn't recognise the heater power and stops working with "Warning #13 Mains frequency error." (I didn't know that from the start, had to find it out..)
I used a DPDT switch capable of 6A/125V. Be sure to use a switch that can handle the 5A of the 48V mode, the 10A of the 24V mode are divided into 2x5A so that's ok for the switch, it doesn't have to be a 10A type.

The station was delivered last week and today I had the time to modify it to accept C470 cartridges (JBC-tips, 48V) as well as C245 cartridges (24V).

After a little bodging and adding the 2pole DPDT (6A/125V) switch I now have a manually switchable HD-2B soldering station I can use all types of C470 and C245 cartridges for soldering jobs demanding high and higher power/heat*. 
I do only switch between 24V and 48V mode with the station switched off or when idle (no heater current flowing) though.

HD-2B heating a C245 cartridge:


HD-2B heating a C470 cartridge:


I put the switch on the back right above the power inlet:


The modification I made:


edit: There's a third connection involved with the 12V supply, that i didn't show: It might be a NTC sharing one connection with the 12V supply. Didn't modify.

edit²: *-compared to my T12 KSGER OLED-soldering stations with self-assembled alternative power supply.
The T12s have become my daily driver and have pushed out my Wellers completely.

[URI]

I'd like to add some further information that results from an answer to my posting over in the TEA thread:
(https://www.eevblog.com/forum/testgear/test-equipment-anonymous-(tea)-group-therapy-thread/msg3552221/#msg3552221)

[description of modifying the JBC HD-2B snipped]

edit²: *-compared to my T12 KSGER OLED-soldering stations with self-assembled alternative power supply.
The T12s have become my daily driver and have pushed out my Wellers completely.

I'm using a Weller WS81 and have been thinking about a TS12 or JBC CD-2BQF.

Is it just a reflex of an TAE addict, or are there substancial differences in performance?

Let's say, a Weller Magnastat kind of very old shool soldering system is 20 points on a scale and the WS81 is 100.  What would a TS12 score, what a JBC?

In my case it's clear that there's a strong reflex of a TE Addict involved. 

I don't have a Weller WS81, I used WECP-20 with LR21 handpiece before.
Both have a classic approach of solder tips and heater being separate and thus not thermally connected ideally.
This limits thermal efficiency being inferior to Hakko T12 (or clone T12) tips or JBC tips (eg. C210, C245, C470..) that incorporate the heater into the tip ("cartridge") near to the soldering tip itself.

If you replace a Weller WS81 with a JBC CD-2BQF I'd expect the JBC superior in thermal performance, because of
1. the sheer electrical power ratings:
Weller WS 81: 80W iron/95W station
JBC CD-2BQF: ??W iron/120W station

2. the better thermal performance of the JBC tip as I mentioned before.

I wouldn't expect the T12 soldering stations being clearly superior to the WS 81 - the T12 clones deliver 70W max. into the tip. One could assume that the integrated heater compensates some thermal performance in comparison to the 80W with lower thermal efficiency of the WS 81.

What I can clearly state is the better thermal performance of my T12 clones over the Weller WECP-20 with 50W max soldering iron power.

I like the T12 and my JBC HD-2B for enabling me soldering at lower temperatures in general. That's the benefit I like most.
To sum it up: With the better thermal performance I am able solder lead-free at the same or even slightly lower temperatures than I was used to using leaded solder with the WECP-20/LR21.

The WS 81 is a nice station. Personally I wouldn't have replaced it with a T12 station if I have had one.   

Just my 2 cents. 

[CristianTM]

Hi !

Very interesting post. I searched days for that.
Please tell me WHERE you cut the wire between two 23,5v ? On the transformer or on the PCB ? one wire or two wires ?
For me  works only this version.
Thanks

WBR,
Cristian.

[floroiug]

Hello. I bought jbc hd-2b and the types are very thick. I would like to use c245. please show me exactly what changes you have made inside the equipment. I would like to make the change myself but I need your help. I'm a beginner but with your help I can handle it