Please help identify this diode.

[diif]

A BaByliss razor that has had 19v instead of 12v due to a faulty charger.
Can someone identify the component at D2 ? , i guess it is a diode of some sort.
It has the markings GW 280.

Thank you.

[budm]

Re: Please help identify this diode.

Can we the other side of the board? It looks like it is used as blocking diode.
GoodWork Semiconductor:
http://www.goodwork.com.tw/

[diif]

Re: Please help identify this diode.

Thanks budm

[budm]

Re: Please help identify this diode.

OK, it is very simple circuit from what I can trace from the pictures, those Diode can be typical 1N4000 series. Those burn resistors, not sure what the values are for R1, R2 which are used to limit the charging current to the batteries.
I do not think D2 is bad but D1 is damaged which may be due to shorted out batteries.

[tw2005]

Re: Please help identify this diode.

OK, it is very simple circuit from what I can trace from the pictures, those Diode can be typical 1N4000 series. Those burn resistors, not sure what the values are for R1, R2 which are used to limit the charging current to the batteries.
I do not think D2 is bad but D1 is damaged which may be due to shorted out batteries.

I'm thinking 3 x 100ohm, you can see the marking on 2 of them 101.

[budm]

Re: Please help identify this diode.

I think you are correct, the one for LED is 100 Ohms, so the other two are connected in parallel to get 50 Ohms. I think 12VDC feeding this board is too high for charging 2.4V 600mA batteries. Lets say that it is charging at 0.1C (60mA for about 10 hours charging time), the voltage drop on that around 50 Ohms will be about 3V, so 12V feeding is way too high may that is why it burns up.

[tw2005]

Re: Please help identify this diode.

I think you are correct, the one for LED is 100 Ohms, so the other two are connected in parallel to get 50 Ohms. I think 12VDC feeding this board is too high for charging 2.4V 600mA batteries. Lets say that it is charging at 0.1C (60mA for about 10 hours charging time), the voltage drop on that around 50 Ohms will be about 3V, so 12V feeding is way too high may that is why it burns up.

Totally missed the LED in your sketch. So are you saying the wattage of those resistors is too low to handle the current through them.

[budm]

Re: Please help identify this diode.

I think when 12V is applied way too much charging current is forced into the batteries, and if the battery pack has one (or both) shorted cell, then it will burn up badly.
12V - 2.4V = 9.6V on the 50 Ohms resistor network, about 192mA will be flowing through the resistors, that is lots of power (1.8W).

[tw2005]

Re: Please help identify this diode.

I think when 12V is applied way too much charging current is forced into the batteries, and if the battery pack has one (or both) shorted cell, then it will burn up badly.
12V - 2.4V = 9.6V on the 50 Ohms resistor network, about 192mA will be flowing through the resistors, that is lots of power (1.8W).

yeah, those would not be rated that high.

[diif]

Re: Please help identify this diode.

Thanks for everyone's input, i have replaced the 3 100ohm resistors and after thinking about the circuit i realised that D2 is on the other side of the battery and probably wasn't affected by the 19v, I don't have a smd diode for D1 but i soldered on a normal one to test and surprise it now charges and works, the batteries have survived. I have ordered a SMD diode.

The burning up was caused by 19v from the charger instead of 12v i think. Or should i increase the two 100ohm resistors to reduce the power to the batteries ?

[diif]

Re: Please help identify this diode.

It seems the owner has been using the wrong charger, after some investigation, this trimmer should use a 5.6v 80mA charger not the 12v one they gave me.

[budm]

Re: Please help identify this diode.

OK, that is more like it, that the charger should be around 6V, if you look at the charger for your cordless phone, it will be 6VDC adapter since most cordless phones use the same batteries.
Thanks for the follow-up info.

[diif]

Re: Please help identify this diode.

Thanks budm and tw2005, if it hadn't been for you questioning the voltages/resistors then i don't think i would have checked.

[Duncanbest]

Re: Please help identify this diode.



SM280A ; A ---> package SMA

SM280B ; B ---->package SMB