HELP for a 7th gd science project. HYPOTHESIS: do disposable AA cells last longer than rechargeable cells in a portable CD player? SET-UP: 2 AA cellS driving CD player. In series with cd PLAYER is an ampmeter; a DVM measures cell voltage. Added a digital clock to stop when the batteries discharge enough to stop the CD Player. THE PROBLEM: the CD player stops playing within an hour but the clock still ticks. The clock uses only 1 AA cell whereas the CD uses 2. The clock uses only .16mA and the CD starts at 300mA then drops to 120mA after 30 sec. Tried, among other configurations, to add 0.5 ohm resistor in series with CD player to drive the clock but this produces an IR drop of only 0.6V or so, not enough to drive the clock. QUESTION: is there a timer with a sensing input that I can buy, or build, that I can connect to this lab set-up in order to sense when the CD player stops running? It could be connected to sense the current because the current drops to zero when the CD player shuts off. Would an inductor in series with CD player be the appropriate component to produce a pulse? PLEASE HELP, DEADLINE IS LATE JANUARY.