The entry level power supply in the Unilab Retro range. The Lockable Power Unit provides a.c. or d.c. at 2, 4, 6, 9 or 12 volts, at up to 4 amps. This unit is well suited to everyday power requirements, such as basic electricity, ray optics boxes and immersion heaters. The voltage is selected using a five-position switch, and can be locked either at a particular voltage, or within a range of voltages, by way of hex socket screws surrounding the selector switch. An Allen key is provided for the teacher or technician to set the desired locks.

The form of the output is set by a separate switch, either a.c. or unsmoothed, unregulated d.c. Two shrouded 4mm sockets provide the output, and the shroud can be partially unscrewed for other types of connection, such as bare wires. a.c. and d.c. are output from the same sockets, and never simultaneously, preventing students from connecting the a.c. and d.c. outputs together.

The unit has two in-built layers of protection. The first is a thermal trip on the secondary circuit, with a reset button for when the problem load has been disconnected. The second is a 1A mains fuse, accessed from the front panel, on the primary circuit.

Size: L290 x W165 x H165mm.