Guidance needed - resistor across switch legs (phantom power, racking audio module)

[jon l]

I want to add 48v phantom power to an audio input module from an old mixing desk. I know little about what I am doing but there is straightforward info on web, plus I have in front of me example of similar prof. racked modules. With these, the on/off switch has a resistor across two of its legs, shown below

is this there for safeguard or something? I measure about 8kohm across the resistor in situ.

Thanks in advance!

 

[JensenHealey]

Could be a light in the switch and the resistor is used for that

 

[jon l]

yes, there's a lamp in the switch

 

[stevec67]

A LED, probably. A mains neon needs about 4.7 x 10^4 ohms IIRC, a TFL of correct voltage none, 8k sounds right for a LED, dependent of course on supply voltage.

The colour code for that resistor says 8.2k +/- 5%.

 

[martin clark]

^ and if that 8K2 resistor connects 48vdc as a supply through an LED to 0v that implies about 5.6mA -yep, I concur, right about where you'd power an LED indicator.

(As such it's a non-critical value BTW, anything 4k7-22k or more would do the job; larger value resistor = dimmer indicator)

 

[jon l]

great input thanks guys