Hi there. Probably a simple question for most. but that is this resistor in the photograph and whats it for? is it really needed.

I want to buy this component of http://farnell.com but not sure what to get

Thanks in advance for any help given

 

Hi there. Probably a simple question for most. but that is this resistor in the photograph and whats it for? is it really needed.

I want to buy this component of http://farnell.com but not sure what to get

Thanks in advance for any help given

It appears to be a bleeder resistor. It is there to discharge that large power supply capacitor, which could deliver a fatal shock after the supply is turned off.

 

1.2k 3-5watt
Max.

 

1.2k 3-5watt
Max.

ok thank you

 

It is a 1.2K 5% resistor. It looks like 5W, it is a ceramic type to handle the heat.

@MaxHeadRoom is stalking me from in front.

 

It is a 1.2K 5% resistor. It looks like 5W, it is a ceramic type to handle the heat.

@MaxHeadRoom is stalking me from in front.

would this resistor do the same job please

https://ie.farnell.com/vishay/cw0051k200je12/wirewound-resistor-1-2kohm-5w/dp/1278281?st=1.2K

 

would this resistor do the same job please

https://ie.farnell.com/vishay/cw0051k200je12/wirewound-resistor-1-2kohm-5w/dp/1278281?st=1.2K

It certainly appears to be a good replacement.

 

hope i dont get an electric shock now when i solder it in thanks for your help

 

hope i dont get an electric shock now when i solder it in thanks for your help

Make sure the power is off. Put on gloves, short out those terminals in case that is a bleeder resistor on something capacitive.

MAKE SURE THE POWER IS OFF

AND, TURN OFF THE POWER

 

Do you need another resistor like the one shown? What's wrong with that one? Looks good.

I don't know what it's used for.....but til I did, I would not replace it with a wire wound.

 

What's wrong with that one? Looks good

Leads broken off on the left side.
SG

 

Ok, thank you, only one question left, what does it do?

 

What does the resistor do? That depends a whole lot on what the device it is connected to is. If it is a power supply as some presume, then it sets a minimum current that the supply will bve delivering. Some types of regulator circuits need to have a load connected at all times to function properly.
It appears that it may have been soldered to the end of the red wire's terminal, so it may have been installed for a reason.. When installing the replacement fist be sure that the item is unplugged, not just switched off. AND, leave the resistor leads longer so that there is some ability to flex without the next resistor breaking as well.

 

What does the resistor do? .

Bleed down resistor!
Max.

 

Bleed down resistor!
Max.

What a "bleed down resistor" does is to draw current to discharge the capacitors in a power supply. This function is mostly useful in those power supplies that have larger output capacitors and the voltage control does not cause those capacitors to discharge when the voltage setting is reduced, and whatever load current is drawn does not discharge them very rapidly. In power supplies where the output voltage is high enough to be a shock hazard they serve also to drain the voltage when the supply is switched off, to reduce the shock hazard a bit.

 

Do you need another resistor like the one shown? What's wrong with that one? Looks good.

I don't know what it's used for.....but til I did, I would not replace it with a wire wound.

From the photo it is almost certainly already wirewound. Everything about it looks like a bleeder. Even if it is not, such a large power resistor is extremely unlikely to be in an inductively sensitive circuit.

 

I guess something like this, though you would need to check the measurements (data sheet lower down the link for different powers):
https://www.aliexpress.com/item/2W-...lgo_pvid=281d63a8-2e75-4823-b060-aa5b6cd5ac8f

 

I guess something like this, though you would need to check the measurements (data sheet lower down the link for different powers):
https://www.aliexpress.com/item/2W-...lgo_pvid=281d63a8-2e75-4823-b060-aa5b6cd5ac8f

would this resister do the same job though??

https://ie.farnell.com/vishay/cw0051k200je12/wirewound-resistor-1-2kohm-5w/dp/1278281?st=1.2K

 

would this resister do the same job though??

https://ie.farnell.com/vishay/cw0051k200je12/wirewound-resistor-1-2kohm-5w/dp/1278281?st=1.2K

That Farnell resistor is a direct replacement according to the photos and appearance. It is the proper choice.

 

That Farnell resistor is a direct replacement according to the photos and appearance. It is the proper choice.

thats great. thanks again