DESCRIPTION The TO-5 relay, originally conceived and developed by Teledyne, has become one of the industry standards for low-level switching from dry circuit to 1 ampere. Designed for high-density PC board mounting, the Series 712 relays are some of the most versatile ultraminiature relays available because of their small size and low coil power dissipation. The following unique construction features and manufacturing techniques provide excellent resistance to environmental extremes and overall high reliability: • All welded construction. • Unique uni-frame design providing high magnetic efficiency and mechanical rigidity. • High force/mass ratios for resistance to shock and vibration. • Advanced cleaning techniques provide maximum assurance of internal cleanliness. • Precious metal alloy contact material with gold plating assures excellent high current and dry circuit switching capabilities. The Series 712D relay has an internal discrete silicon diode for coil transient suppression. The hybrid Series 712TN relay has an internal silicon diode and transistor driver. The integrated packaging of the relay with its associated semiconductor devices greatly reduces PC board floor space requirements as well as component installation costs. By virtue of its inherently low intercontact capacitance and contact circuit losses, the 712 has proven to be excellent ultraminiature RF switch for frequency ranges well into the UHF spectrum. A typical RF application for the TO-5 relay is in handheld radio transceivers, wherein the combined features of good RF performance, small size, low coil power dissipation and high reliability make it a preferred method of Transmit-Receive switching (see Figure 1).