My question, I am using this as a 2nd station and building a complete DIY 936 clone OEM PCB circuit and non OEM parts etc.¬† I need suitable transformers, for these units.¬† I read the 936 is ~ 60VA transformer, I can find a 50VA to fit the transformer mount posts (of the case) but suggest a 73~75VA unit (or even a 100VA) would be more suited.
I'm a cheap arsed but know the need to pay for a decent iron/tips/controller PCB and transformer so any advice welcomed (even considering buying a proper Hakko 907M iron, full price, but where?).
Hakko 936 Schematic: http://dalincom.ru/datasheet/HAKKO_936_schematic.pdf
Also I'm assuming the Hakko 936 station is a 50VA transformer?
Finally.... Ok made some Hakko OEM copy PCBs and ordered a front panel and new case from fleabay as well as a host of parts, including new transformers. I now have a 936 station OEM copy ( although I'm using a 75VA 24V 2ndry transformer) and an original 907 iron (from RS) including a handful of OEM Hakko tips. Also changed the main power switch to a neon type and put in proper M205 cartridge fuses on this main switch, with a new sub PCB for this. Also put M205 cartridge fuse on the main PCB for 24V (transformer secondary) pwr to PCB.¬† Cannot think for the life of me why Hakko didn't originally do this.
Also doing the "on power LED mod".¬† Forgive my photographic skills!
This new system heats much much faster than the Yihua (25~30 secs or less with 3.2mm chisel tip) and has no problems doing big tasks and has much better thermal stability. Pretty much because the Yihua transformer was ~35VA! The Yihua heater tip is a nichrome wire in a ceramic tube and the ceramic end cracked on mine and is showing nichrome heater wire...barely ~1mm away from the tip metal (ground). Not good.
Also I found the Yihua uses a non std thermocouple temp feedback (mentioned before by others) which is not the same as the Hakko 907 iron PTC feedback. Funny enough I found a place in Aust selling very good copies of the 907 iron with the same ceramic heater and PTC feedback as the Hakko for ~$20, not bad indeed! Now I can change irons and keep calibration, I've ordered a thermocouple tip temp calibrator),
Just doing the 2nd station now but using a 50VA transformer for the 2nd one.
One for the safety inspectors.....¬† my Yihua soldering station they wired the active/neutral wrong and switch/fused the wrong line. The Active (Line) was the blue wire, the Neutral (N) was the brown wire (it should be the other way round the moulded plug is made/wired wrong). The main switch also switched and fused this brown (Neutral) wire. At least the earth was correct! Safety standards......Ahhh yes China has a long way to go!