Selected and delivered energy displays.
(a) The selected energy display logic receives its information from two
sources: (1) the energy selector switch and (2) the paddle sensor block. The latter has
priority over the selector switch. The information for the display is contained in a memory
integrated circuit (IC) and displayed according to the binary information from the sources
(b) This block also generates a slow pulsed signal once the charge
button is depressed. The signal changes to a steady dc level once the capacitor bank is at
the right voltage. All the flashing lights on the panel and on the paddles, plus a beeper,
are driven from this signal.
(c) The delivered energy meter, isolated from a ground, senses and
integrates the signal developed by the load current through R1 and feeds a square law
integrator according to RXI-2w rule. This value is sampled and held for approximately 10
seconds. The digit R1 volt meter fed by its output, displays the voltage which is calibrated
to be representative of the delivered watt/seconds into the load.
(a) The defibrillator can be powered directly from line selectable 120v or
240v, 50/60Hz, or from a self-contained NiCad battery.
(b) As soon as the defibrillator line cord is plugged into an outlet, the
system switches over to ac operation by passing into the battery which is recharged, and
connecting into its place a 12v preregulator.
(c) Only the first supply is put into action when the following conditions
exist: (1) the battery operation is switched in (cord removed from outlet) or ac operation is
chosen and, (2) the unit is turned ON by a combined low battery shutoff and system turn
On circuit. It supplies all the auxiliary, floating, and grounded voltages including the power
to the charge logic which, after the CHARGE command, can start the main invertor.
(d) The heavy load makes the battery voltage drop below the shut off
voltage and turns the unit off. However, in this instance, the first power supply and the low
batt shut off are powered by a 12v regulated booster line fed by the main invertor each
time it is turned running.
(8) Paddle preamplifier. With the exception of the high voltage input
protection and the more elaborate common mode rejection circuit, this amplifier is very
straight forward and simple in its configuration. In order to restrict noise, its output is
heavily filtered before the signal leaves this board for the corresponding monitor paddle