| 摘要 |
<p>For charging a battery (6) a self-oscillating power supply circuit is used in which energy is stored in a transformed (Tr) during the so-called forward intervals, which energy is applied in the form of a charge current to the battery (6) during the so-called flyback intervals. To prevent overcharge of the battery (6), the circuit is provided with an acculmulator voltage protection circuit (10) receiving its power supply from the battery (6), to which circuit a fraction of the battery voltage is applied by means of a voltage divider (R3, R4) which is arranged across the battery (6) by means of a switch (S1) during the flyback intervals. To prevent the voltage drop accross the internal resistance of the battery from influencing the measurement of the battery voltage, the battery voltage is measured after the end of a flyback interval and before the commencement of the next forward interval. To this end the inputs (11, 12) of the accumulator voltage protection circuit (10) are short-circuited with the aid of two diodes (D1, D2) during the flyback intervals.</p> |
