| 摘要 |
A measuring circuit (1) for e.g evaluating the current passing through a battery produces analog signals representing the potensials at two input terminals (9, 11) which are connected at each side of a shunt resistor (13). The circuit has a high-range stage (23) and a low-range stage (29), the two input terminals being alternatively connected to an input of the high-range stage. The output of the high-range stage is connected to an input of the low-range stage and the output terminals (5, 7) of the stages are output lines of the circuit. The stages comprise amplifiers (X2-1, X2-2) and hig-pass filters (25, 31) connected in front of the amplifiers. A line (21) for clock pulses is connected to a switching circuit (19) for the alternating connection of the input terminals. The switching circuit can comprise three electronic on-off switches (X1-1, X1-2, X1-3). The amplifiers can be differential amplifiers, the positive and negative inputs of which are biassed to a voltage having a value being half the value of a supply voltage. This will allow negative potentials or input signals to be representad by positive output signals lower than the bias value and positive input signals to be represented by positive output signals larger than the bias value. |
