The PZ series of power supply units was designed principally to power the Sinclair range of amplifiers, which needed successively more powerful power supplies as the years went by. Typified by 1969's PZ5 (right) they were not the most exciting products that Sinclair ever made. Nonetheless, they were crucial components in the highly successful Project 60 range.

The PZ range eventually comprised six power supply units released over a period of nine years. These were:

• PZ3 (1966)
• PZ4 (1968)
• PZ5 (1969)
• PZ6 (1970)
• PZ8 (1970)
• PZ8 Mk 3 (1975)

For technical details of each unit, see the original advertisements in the gallery on the right.