How to measure voltage across a load

[D-Dog]

I just recieved a DMM for Christmas and am trying to figure out how to measure the voltage of my stinger 74 (also recieved) under load. I know the bulb draws 2.73 amps, however I am not sure at what voltage this is. can I just place the leads between the bulb terminals with the bulb on? BTW the DMM is a RadioShack 46 auto-scaling DMM

 

[Glock40]

I am sure others will chime in but yes if you place your meter leads on the pins of the bulb while it is on you will get the voltage that the bulb is at under load.

 

[Flash_Gordon]

Correct. You actually answered your own question in your thread title.

Measure voltage across and current in series with the load. The bulb contacts would be the most accurate place to measure actual voltage. This would account for switch and other circuit losses. To see these losses, also measure across the battery while the light is on.

Mark

 

[D-Dog]

wow, I anwsered my own question and didn't even know it. The bulb read 7.43 under load, however one little problem is that in my haste to keep the probes connected and read the meter, i kinda slipped with the positive probe and it touched the bulb... aka little burnt plastic spot on bulb. Does this mean the bulb will fail in a few minuites? Is there any way to save the bulb? (wa 1274)

Edit: Guess I should add the socket on the scorpion is in a little hole...just so it doesn't seem I'm a total klutz

 

[thezman]

Once the plastic cools, it will peel right off the bulb.
Clean the bulb with a little alcohol, it'll be fine.