This timer relay from Schneider Electric lets you set a time delay when turning equipment on. It fits on a panel through a standard 22mm mounting hole for ease of installation – its clamping width of 1 to 6mm makes it ideal for attaching to thinner panels. The solid-state relay will switch currents of between 10mA and 10A at voltages of up to 24V DC, making it a versatile choice. It has an extremely fast switching time of only 5ms for a rapid response and high levels of efficiency.

• Light weight of only 27g to reduce strain on your panel
• Wide operating temperature range of -20°C to +60°C for use in demanding environments
• Screw terminals for simple and secure connections
• Output short-circuit protection for enhanced electrical safety
• Time range of 0.5s to 10s for flexibility when setting time delays

• Industrial process instruments
• Model vehicles
• Radio-controlled models
• Pressure and flow-rate sensors

An open collector output, like this one, is a low-powered, solid-state switch. Unlike electromechanical switches, it's very fast, uses little power and is less susceptible to wear. It can only be used for DC (direct current) switching.