SERIES 421 MAGNETIC-LATCHING ESTABLISHED RELIABILITY TO-5 RELAYS SPDT SERIES RELAY TYPE DESIGNATION 421 SPDT basic relay 421D SPDT relay with internal diode for coil transient suppression SPDT relay with internal diodes for coil transient suppression and polarity 421DD reversal protection The Series 421D and 421DD utilize discrete silicon diodes for coil DESCRIPTION suppression and polarity reversal protection. The magnetic-latching TO-5 relay, originally conceived and developed by Teledyne, has become one of the industry standards By virtue of its inherently low intercontact capacitance and contact for low-level switching from dry circuit to 0.5 ampere. Designed for circuit losses, the 421 relay has proven to be an excellent high-density PC board mounting, its small size and low coil power ultraminiature RF switch for frequency ranges well into the UHF dissipation make the 421 relay one of the most versatile spectrum. A typical RF application for this TO-5 relay is in handheld ultraminiature relays available. radio transceivers, wherein the combined features of good RF performance, small size, low coil power dissipation and high The following unique construction features and manufacturing reliability make it a preferred method of transmit-receive switching techniques provide excellent resistance to environmental extremes (see Figure 1). and overall high reliability: All welded construction. The Series 421 magnetic-latching relays are ideally suited for Unique uni-frame design providing high magnetic efficiency and applications where coil power dissipation must be minimized. The mechanical rigidity. relays can be operated with a short duration pulse. After the contacts High force/mass ratios for resistance to shock and vibration. have transferred, no external holding power is required. Advanced cleaning techniques provide maximum assurance of internal cleanliness. The magnetic latching feature of the Series 421 provides a memory Precious metal alloy contacts material with gold plating assures excellent high current and dry circuit switching capabilities. capability, since the relays will not reset upon removal of coil power. PERMANENT MAGNET MAGNETIC CIRCUIT A MAGNETIC CIRCUIT B SOFT IRON CORE A PRINCIPLE OF OPERATION Energizing Coil B produces a magnetic field COIL B COIL A opposing the holding flux of the permanent magnet ENVIRONMENTAL AND SOFT IRON in Circuit B. As this net holding force decreases, the SOFT IRON CORE A PHYSICAL SPECIFICATIONS CORE B attractive force in the air gap of Circuit A, which also AIR GAP SOFT IRON results from the flux of the permanent magnet, ARMATURE Temperature MOVING 65C to +125C CONTACT becomes great enough to break the armature free (Ambient) of Core B, and snap it into a closed position against Vibration Core A. The armature then remains in this position 30 gs to 3000 Hz STATIONARY CONTACT (General Note 1) upon removal of power from Coil B, but will snap back into position B upon energizing Coil A. Since operation depends upon cancellation Shock 100 gs, of a magnetic field, it is necessary to apply the correct polarity to the relay coils as (General Note 1) 6 msec, half-sine indicated on the relay schematic. When latching relays are installed in equipment, the latch and reset coils should not be pulsed simultaneously. Coils should not be pulsed Acceleration 50 gs with less than rated coil voltage and the pulse width should be a minimum of three times the specified operate time of the relay. If these conditions are not followed, it is possible Enclosure Hermetically sealed for the relay to be in the magnetic neutral position. Weight 0.089 oz. (2.52g) max. 421 Page 1 SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE 2005 TELEDYNE RELAYS www.teledynerelays.com 421/1205/Q1INSERTION LOSS SERIES 421 GENERAL ELECTRICAL SPECIFICATIONS (65C to +125C unless otherwise noted) (Notes 2 & 3) Contact Arrangement 1 Form C (SPDT) Rated Duty Continuous Contact Resistance 0.125 ohm max. before life 0.225 ohm max. after life at 0.5A/28Vdc (measured 1/8 from header) Resistive: 0.5 Amp/28Vdc Contact Load Ratings (DC) Inductive: 200 mA/28Vdc (320 mH) (See Fig. 2 for other DC Lamp: 100 mA/28Vdc resistive voltage/current ratings) Low Level: 10 to 50 A/10 to 50mV Resistive: 250 mA/115Vac, 60 and 400 Hz (Case not grounded) Contact Load Ratings (AC) 100 mA/115Vac, 60 and 400 Hz (Case grounded) 10,000,000 cycles (typical) at low level Contact Life Ratings 100,000 cycles min. at all other loads specified above Contact Overload Rating 1A/28Vdc Resistive (100 cycles min.) Contact Carry Rating Contact factory Coil Operating Power 290 milliwatts typical at nominal rated voltage 25C Operate Time 1.5 msec max. at nominal rated coil voltage Contact Bounce 1.5 msec max. Minimum Operate Pulse 4.5 msec width rated voltage Intercontact Capacitance 0.4 pf typical Insulation Resistance 10,000 megohms min. between mutually isolated terminals Dielectric Strength Atmospheric pressure: 500 Vrms/60Hz 70,000 ft.: 125 Vrms/60Hz Negative Coil Transient (Vdc) 421D/421DD 1.0 max Diode P.I.V. (Vdc) 421D/421DD 100 min. DETAILED ELECTRICAL SPECIFICATIONS (65C to +125C unless otherwise noted) (Note 3) 421-5 421-6 421-9 421-12 421-18 421-26 BASE PART NUMBERS 421D-5 421D-6 421D-9 421D-12 421D-18 421D-26 (See Note 8 for full P/N example) 421DD-5 421DD-6 421DD-9 421DD-12 421DD-18 421DD-26 Nom. 5.0 6.0 9.0 12.0 18.0 26.5 Coil Voltage (Vdc) Max. 6.0 8.0 12.0 16.0 24.0 32.0 421/421D 61 120 280 500 1130 2000 Coil Resistance (Ohms 10% 25C) 421DD (Note 4) 48 97 280 500 1130 2000 Min. 78.0 45.8 25.7 19.6 13.4 11.2 Coil Current (mAdc 25C) (421DD Series only) Max. 111.8 63.0 34.9 26.7 18.8 15.2 421 3.5 4.5 6.8 9.0 13.5 18.0 Set & Reset Voltage 421D 3.7 4.5 6.8 9.0 13.5 18.0 (Vdc, Max.) 421DD 4.5 5.5 7.8 10.0 14.5 19.0 PERFORMANCE CURVES (NOTE 2) TYPICAL RF PERFORMANCE TYPICAL DC CONTACT RATING (RESISTIVE) 0 .1 300 .2 .3 250 .4 200 10 1.92 20 1.22 150 30 1.07 100 40 1.02 50 1.01 50 60 1.00 70 1.00 .01 0.5 .1 .5 1.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 LOAD CURRENT (AMPS DC) FREQUENCY (GHz) FIGURE 1 FIGURE 2 2005 TELEDYNE RELAYS SPECIFICATIONS ARE SUBJECT TO CHANGE WITHOUT NOTICE 421 Page 2 www.teledynerelays.com 421/1205/Q1 RETURN LOSS (VSWR) ISOLATION ACROSS CONTACTS dB VSWR LOAD VOLTAGE (VDC)