Help with R.G's math

[JOHNO]

Over at geo in the technology of the fuzz face R.G explains how to measure the gain of GE transistors. Do i just set my DMM to DC voltage as if i was checking voltages at a transistor in circuit or measuring a battery? The math he uses confuses me for example (4ua)*(100)*(2472)=0.9888V How does that work? And another (100E-6)*2472=247mV. Any one know what goes on here?

[mac]

(4ua)*(100)*(2472)=0.9888V

4ua = 4 micro ampere = 0.000004 amp = 4E-6 amp = 4/1000000 amp

0.000004 amp * 100 * 2472 Ohm = 09888 Volt

(100E-6)*2472=247mV

100E-6 = 1E+2 * 1E-6 = 1E-4 = 0.0001

0.0001 amp * 2472 Ohm = 247mV = 247 milliVolt = 247E-3 Volt = 0.247V



mac

[JOHNO]

Thanks mac. It seems I may not have explained myself properly. What im after is how to do the sum. You know, how do i put those numbers in my calculator and get the answers that RG gets?
EDIT: Oh now i see it (i think). I was never any good with math spent too much time dreaming about the young lady sitting next to me. Thanks again Mac.

[mac]

I posted the math behind RG test because you may need to know the gain of your transistors under different base currents, that is, gain is a function of the current going into the transistor:
http://www.diystompboxes.com/smfforum/index.php?topic=45481.0

If you are familiar with Excel you can use the equations to get gain and leakage.

I was never any good with math spent too much time dreaming about the young lady sitting next to me.

I know exactly what you mean, that´s why I´m 42 and single

mac

[JOHNO]

What does the "E" represent? And why does 100E-6=1E+2*1E-6? I still haven't got a grasp on that yet.

[Roobin]

E means "x10 to the power of the number after" so 100E-6 is 100 (x 10^-6), and 0.1E2 (or can be written as 0.1E+2) is 0.1 (x10^2).

100E-6=1E+2*1E-6? Think of it as (1E+2) x (1E-6). That should make it clearer.

[StephenGiles]

Maths!

[mac]

Maths!

Scary, uh?

mac