Forums » General Electronics Discussion

2 parter here. I am trying to prove a theory for myself and other basic (very) electronic people. I have done the math and I have done the drawing and they come out to different results in terms of amps drawn. My math: 4.2 volt battery a single .4 ohm resistor Amp draw = 10.5 amps

If I then add another .4 ohm resistor in parallel to the first does the amp draw then go to 21 amps?

thanks for any help or links you can provide. my drawing just doesn't seem to come out even in this very basic schematic. I am sure it is my noobness.

Rob

Link to drawing https://www.circuitlab.com/circuit/uje57v/basic-e-cig-mod/

Your maths is fine.

The porblem is it assumes that the 4.2V source is ideal and therefore has no internal source resistance.

The battery models in CL are a crude attempt to model a real battery and so have a finite source resistance. Double click on the symbol to see the parameters.

Also, beware that the CL Ammeters can be set to have a non-zero insertion series resistance. Their default setting is 0 but again, double click on the symbol to see the parameters.

To verify your idealised maths, replace the battery with an Ideal Voltage Source of 4.2V, set the Ammeter resistances to 0 and all the sums will be right.