EEVblog Electronics Community Forum

Hi,

If by any chance any of you has a Li-Ion powered handheld Dremel cutting tool (such as the 8200) with a 875 battery, or a Dremel with a 876 charger, or a Bosch BC330 charger (seems to be the same but rebranded), PLEASE help my by opening it !

Please check attached pictures.

I had the European version (230V input) and stupidly connected it to 120V in North America and it blew up (I know I'm stupid - but the point is now to try to repair it). I'd like to find the values from an European charger, but it's possible that the values are in fact the same for the US charger and that the failure is unrelated, so I'm also interested in the internals of a US charger.

Components are blown and I can no longer see the values (chg_damage.pcb - a resistor melted !)... so if you can open up your charger and look at the values it'd help a lot !

I need the values for :
- The small TO92 transistor (it's a 2N.......)
- The big TO220 transistor (reads ....K8BZ ....02E V3)
- The 3 resistors (or similar ?) in between (including the one that melted)

Thank you very much

uski

Hey thank you very much for the pictures, it is awesome, I didn't even expect to get a reply before months

About converting the BC430 to 220V, this can be done as some guy is selling a kit here :
http://www.ebay.com/itm/CONVERSION-KIT-for-Bosch-BC430-Charger-Convert-120V-To-220V-As-AL1130-model-/221576242465

If you look at his feedback he has a negative comment of someone saying "hey this guy only shipped me some capacitors" which would seem to say that you only need to replace the caps for 400V caps (including the big one and I'm not sure what else - maybe a varistor or something like that).

So I'm pretty sure you can convert your charger.

If you own a FLIR E4 (hmm not sure why you would), make sure to check the temperature of the components after the modification (I did convert a Roomba charger from 120V to 220V by changing the caps but components were getting too hot).

Many thanks ! I'll try a fix tomorrow if I have the parts !

This is awesome about time I convert my 120v to 240v thanks for the pictures guys.

If i'm reading this right you plugged a 230v device in to a 120v socket and it blew up? I'm shocked that happened, unless it really did not like 60hz!

I have one of these chargers in UK 230 voltage, but mine is popping fuses.
At the top, it's a fusible resistor rather than the glass fuse. The resistor popped with an impressive bang when I turned it on at the wall one day, so I opened it up and changed the resistor, but it just immediately pops again.
No other components are showing any sign of damage or overheating and it's not had heavy use (lives in it's case rather than being used regularly, would expect it's not had more than 10-15 charges over its lifetime)
Does anyone have any pointers about what I might look at changing to repair or diagnose further? The large transistor seems like an obvious one?

I would guess all 4 bridge rectifier diodes are now short circuit, and the power mosfet on the heatsink along with the current sense resistors, and probably the 1M start up resistor as well.

Resistors will be open circuit, basially all low value resistors ( under 10ohm) attached directly to the mosfet are suspect as to being open circuit. As a bonus they going open circuit means it is relatively easy to check in circuit after removing the mosfet. Lower than marked value probably fine, higher than marked open.

What do you think would cause this? Is it the mosfet failing and everything else is just taken out by that?
What's the value of the glass fuse - would I be better swapping the fusible resistor for a glass fuse, as it might go a bit less aggressively? The resistor makes a hell of a bang and it seems lucky it isn't damaging further components when it goes

Old topic..but seems to be still valid.
I just converted  Bosch BC330 US charger to work on 220V.
On recent model the FET is P5NK50ZFP and rated for 500V so I replaced ONLY the electrolytic capacitor to 180uF 400V...nothing else. Charged the battery for 15min and no issues.

Well, not sure the P5NK50Z is suitable for 230V...
It is rated for 500V, but it will have to stand 230 * 1.41 * 2 -> approx. 650 Volts.

* 2 is due to voltage reversal caused by the primary side of the transformer during flyback.

Regards.

Hi All,
I have attempted to convert my 110v bosch BC330 charger to use in 240v. I am no dummy, the 200v cap is the first thing I changed (to 400v), I changed with confidence, tested, and then it was all down hill from there.
that's when i found this post.
I am using the pictures of the 220volt versions posted for component conversion and I am constantly failing!
to convert to 220v, looking at the photos carefully, I am sure I have got all the resistor codes correctly changed.  I am using 6NK90 - 5 amp 900v mosfet and 2N2222 transistor. I keep blowing these up, along with their associated resistors etc.
When i get it working, green light comes on and i measure the secondary voltage on the 470uF 25v capacitor and I get 50 volts. the 300 ohm resistor gets warm! so i cut the power. what am i missing?
I'd really like to know the correct values of resistors on the 220volt version, especially the resistor of the collector of the npn transistor. the pictures are not clear for me to get the colour code. especially the multiplier band. I am currently using a value of 30ohm for the npn transistor collector.
I have purchased a bosch multi-volt 110v - 265v charger from China, for under $30AUD. it's just now, this charger repair is  more of a personal challenge.
bugger me.
I am convinced that the transformers between 110 v and 220v has different amount of turns. from inspecting the transformer part numbers they are different.
has anyone actually succeeded in a conversion from 110 to 220v and still has a working unit after 5 minutes of operation?