Trying to understand JBC C245 cartridge power - Page 1
Forum section: electronics / general

author: EricNava
author_rank: Contributor
timestamp: January 29, 2021, 03:19:33 am
content: Hi all, I have been reading online a lot about DIY JBC stations.I have a Quick TS1200A station now, and I am very happy with it, although I thought it would be cool to modify it to use the JBC C245 cartridges in the JBC handpiece. I know this is probably not a great idea, but want to see if it is feasible.The main thing I am worried about is the power. The JBC tips are around 2.5 ohms for the heater, whereas my Quick station tips are about 4.8 ohms.That would lead me to believe that the JBC tips would not work since they would overload the Quick station.To further investigate, I probed the Quick station while it was powered on, and there is 70V peak to peak on the cartridge. So that is 35V peak, and about 24.7V RMS.From my research the JBC stations also use about 24V RMS to power the heater. If I calculate the power at the handle for the JBC using 24V RMS and 2.5 ohms I get about 235W. Seems much too high since the station is rated for 130W.For the quick station with 24V and 4.9ohms, that is about 125W. That makes sense since the station is rated for about 130W.So the thing is, does the JBC station really deliver 235W to the handpiece for the C245 cartridges? Online they say the peak power is 130W.https://www.jbctools.com/cd-b-standard-soldering-product-1605.htmlThere is probably something i'm missing, or maybe my calculations are incorrect.*Edit I know there are other possible issues with converting the Quick station to use JBC cartridges, such as thermocouple type. But right now just wondering about power. Also I should mention the quick station uses the same 3 terminal type of cartridge where the thermocouple is not in series with the heater.

author: DavidAlfa
author_rank: Super Contributor
timestamp: February 09, 2021, 08:01:22 am
content: The Jbc probably doesn't output 24Vrms when the load is applied. More like 19-20V? Also, I think it skips some AC cycles to measure the temperature?I'd worry more about the Quick power supply than the tip itself, as that power would be only for few seconds when heating from cold.If it's a transformer, I think it will work without problem as long as it's only for very short periods.You'll have to test yourself.

author: EricNava
author_rank: Contributor
timestamp: February 09, 2021, 11:16:16 am
content: Yeah you're right, a jbc will definitely not output full 24V during load and also I've realised there will be some voltage drop in the wire to the iron handle.I tried finding the specs of the transformer in the quick station but, couldn't find anything online.Here is a picture of the transformer for anyone interestedhttps://ibb.co/58XTGtNI am a bit worried about blowing up the quick station if I plug in my JBC handle so I might wait until I have a backup soldering iron before I do testing haha.

author: DavidAlfa
author_rank: Super Contributor
timestamp: February 09, 2021, 12:52:03 pm
content: The transformer should stand the extra load for few seconds. Once hot it usually uses relatively low power.Check the electronics, the switching part (Triac, scr, mosfet, whatever it uses)that will be weak point.If the components can stand at least 150% the power that the jbc cartidge will take, I would try.However the TC output will be probably a lot different, in the best condition it will heat less,and in the worst it will burn the tip.