Patent attributes
The invention deals with a controlling device (22) for an electrical device such as for example a hearing aid (20). The hearing aid (20) includes a power supply (23) and a functional unit (21) controlled by the controlling device (22) via a reset signal (2). In order to reduce undesired behavior of the hearing aid in case of transients, brown-out or other oscillations of the input voltage (1), the controlling device (22) is built such that the functional unit (21) is resetted as long as the rising supply voltage (1) is lower than a startup threshold. Once the functional unit (21) is enabled, it remains enabled as long as the supply voltage (1) does not fall below a shutdown threshold where the shutdown threshold voltage is lower than the startup threshold voltage. This hysteresis is implemented via a reference generator (24) generating a constant reference voltage (27) and a modifiable voltage divider (28) which generates different output voltages (1.1) in dependency of the output of the comparator (25).
