Lockmaster Power Unit

Recommended for general-purpose laboratory and workshop use, particularly in situations where voltage-sensitive components may be damaged by over-voltage. Provides 0-15V a.c. or unsmoothed d.c. in 1V steps at a maximum current of 8.5A. Both a.c. and d.c. outputs may be used simultaneously provided the combined output does not exceed 8.5A. Internal heavy-duty relay switching enables voltage to be switched whilst on full load without switch-contact problems; ensures long switch lifetime. The internal, quiet-running fan will hardly be noticed but it reduces the already low thermal stress in the unit still further, ensuring long life of the instrument. Triple protection is provided by resettable electronic overload trip, thermal transformer trip and slow-blow fuse on the transformer primary. The maximum voltage that the unit can be adjusted to can be locked to a setting chosen by a teacher (or technician) using a key provided. Now the control knob can be adjusted up to the new setting but no further and protects voltage sensitive components such as light bulbs and motors from damage through over-voltage.