VISHAY METAL FILM RESISTORS

[dpm309]

I just received an order from Mouser that included 1 and 100 Ohm, 1 watt metal film resistors made by Vishay/BC Components.  At first I thought they shipped the wrong resistors but I doubled checked the invoice and the data sheet and they are supposed to be 1 watt resistors.  These are the same size as a 1/4 watt resistor (see attached photo).   According to the data sheet, the length is only 6.5 mm and the diameter is 2.5 mm.  I am hesitant to use these because of their size. Has anyone used these before?

Dan

[G._Hoffman]

I've used those - they are fine.  Well, not in those values, but still...


Gabriel

[dpm309]

Thanks for the reply.  After I posted this, I saw where Doug is selling the same resistor with a 1% tolerance.  I'll go ahead and use them.

Dan

[PRR]

The power rating of a resistor is only about how HOT it can get (without smoking or drifting).

The old flowerpot-clay resistors did not like to get TOO hot.

These wee beasties are made like kiln insulators: high-grade ceramic. You can probably take them up to red-heat and safely dissipate 4X the watts of a same-size composition; or get the same watts in a 4X smaller blob.

Don't be fooled. Heat is heat. You know a old-style "1W" resistor needs a lot of space for air to flow. These parts are smaller, but need the same total cooling space.

[ThermionicEngine]

Metal Film resistors have a military rating and a commercial.  Military 1/2 Watt = Commercial 1 Watt.  I think they are fine resistors but I tend to use them where size is an issue, like in new Fender amps where they use 1/4 Watt resistors and I want a more robust resistor.
The board only allows so much room.  (With due notice about heat dissapation as mentioned by PRR above. I just raise them off the board if it is a warm spot.