Battery Amplifier

Once the inbuilt Battery Amplifier or Booster on the 4500 / 5000 is activated for use does it shorten your overall operating time much compared to not using it ?

Boulder

G'day Boulder

Not that i've noticed mate, and if it did it must have been less than 5 minutes run time.
I only use a 5 watt speaker and detect a good 12 hrs a day most times, but i always give
me battery a quick zap around lunch time.

Pete

Thanks Pete.

I see your speaker is a 5 watt job where as the GME SPK07 8 ohm speaker that most seem to use is a Nominal 2 Watts Maximum 3 Watts speaker.

Therefore I assume your 5 watt speaker would draw a few extra milliamps (mA) from the battery during operation and I wonder if there is a formula to work out the current draw of a speaker or a headphone?

Not sure on the formula boulder.
The GME 2watt speakers are too tinny for me, i like a smoother bassier tone with more punch, they are available at Jaycar or OzTronics for 20 bucks, just need to whack a 6mm plug on em.

Pete

hey pete, do you by chance have the order/serial number for the speaker you use?

This is the exact one at Jaycar
$27.45 for the both

Speaker
http://www.jaycar.com.au/productView.asp?ID=AS3185

and the 6.5mm plug
http://www.jaycar.com.au/productView.asp?ID=PP0179

Pete

Boulder - Not that it matters, if you or others want to know...

Minelab GPX4500 - 5000 Koss UR30 Headphones
• Frequency Response: 18-20,000 Hz
• Impedance: 100 ohms
• Sensitivity: 101 dBSPL/1mW
• Distortion: <0.2%
• High Fidelity Stereo phone utilizes an anisotropic magnet and 1.4 mil mylar element for deep bass and tremble clarity

basically high impedance (low current cell phone type) headphones 2 x 1milliwatt (0.001W from the battery at 101dB of signal in your ears)
The Minelab GPX4500 and 5000 have a 68Wh (watt hour) Lithium Ion battery and run for 12hrs on a full charge in normal conditions so, the power drawn by the headphones is a bugger all compared to what the machine needs to operate.

Power (Watts or work over time) used in AC or DC circuits is proportional to the product of Current (Amps) squared, and Impedance (Ohms)

I don't know how much power the amp uses for an external speaker to run but the ouput wattage still comes from the battery so, 8 ohm 5W external speaker, screaming at at Full Volume is gunna pull allot more power than headphones running at max volume only pulling 0.002W max in comparison (about 2500 times in fact)

ND (Elect.Techn).

Thank you ND for your very informative reply.

Not bad info for a Fuse Monkey