Magnetic latching solenoids, manufactured by NSF Controls and available from Aerco employ permanent magnets, coupled with the magnetic circuit of conventional DC solenoids. Features of the magnetic latching solenoids include:

• Pull and attract by supplying only momentary pulse current
• Can provide strong holding force without maintained electrical power
• Release by supplying a reverse pulse of current. A return force is required for this operation.
• Operation by pulse current eliminates any problem of temperature rise
• Memory is retained during power loss
• Operating Load must always be greater than Magnet Force.