A switching network part (SNP) for reversing a network voltage change into a direct current (d.c.) voltage in using a portable electric drill with a quasi-resonance transformer (QRT) where the QRT includes at least two semiconductor elements and a toroid t...

The device is of standard size C or D and has up to four AAA or AA round cells (10) contained in a housing with external dimensions of C or D size consisting of at least two parts (21,22) forming an at least approximately cylindrical external profile and t...