Device for charging an accumulator from an electrical energy source more particularly for an electronic watch

An electronic device for the charging of an accumulator from a source of electrical energy, for use, more particularly, in an electronic watch, said accumulator and said energy source each having a first and a second pole, said second poles being connected together, comprising conducting means having a control electrode and two main electrodes connected respectively to said first poles of the energy source and the accumulator;

• a differential amplifier having two inputs respectively coupled to said main electrodes and an output connected to said control electrode, said amplifier responding to the potential difference between the first poles of said energy source and said accumulator for controlling the conduction of said conducting means;
• and means for adjusting the off-set voltage of said differential amplifier at a predetermined value and polarity, in order to render negligible the voltage drop in said conducting means and to avoid the discharge of said accumulator into said energy source.