MODEL 78 1 1-1/4 Rectangular Multiturn Cermet Trimming Potentiometer ELECTRICAL Standard Resistance Range, Ohms 10 to 2Meg Standard Resistance Tolerance 10% (<100 Ohms = 20%) Input Voltage, Maximum 300 Vdc or rms not to exceed power rating Slider Current, Maximum 100mA or within rated power, whichever is less Power Rating, Watts 1.0 at 70C derating to 0 at 125C End Resistance, Maximum 2 Ohms Actual Electrical Travel, Turns, Nominal 22 Dielectric Strength 500 Vrms Insulation Resistance, Minimum 1,000 Megohms Resolution Essentially infinite Contact Resistance Variation, Maximum 1% or 1 Ohm, whichever is greater ENVIRONMENTAL Seal 85C Fluorinert (No Leaks) Temperature Coefficient, Maximum 100ppm/C Operating Temperature Range 55C to +125C Thermal Shock 5 cycles, 55C to +125C (1% RT, 1% VR) Moisture Resistance Ten 24 hour cycles (1% RT, IR 1,000 Megohms Min.) Shock, 6ms Sawtooth 100Gs (1% RT, 1% VR) Vibration 20Gs, 10 to 2,000 Hz (1% RT, 1% VR) High Temperature Exposure 250 hours at 125C (2% RT, 2% VR) Rotational Life 200 cycles (3% RT) Load Life at 1.0 Watts 1,000 hours at 70C (2% RT) Resistance to Solder Heat 260C for 10 sec. (1% RT) MECHANICAL Mechanical Stops Clutch Action, both ends Torque, Starting Maximum 5oz.-in. (0.035 N-m) Weight, Nominal .09 oz. (2.6 grams) Fluorinert is a registered trademark of 3M Company. Specifications subject to change without notice. Model 78 1-61SIDE ADJUSTMENT (Inch/mm) Model 78P Circuit Diagram Housing Marked On This Surface Molded Plastic Metal Adjustment Screw .110/2.794 0.127 Dia. With .025/0.635 Model No. & 0.07 0.127 Wide X .031/0.787 0.127 Deep Slot Resistance 1.78 Value Marked 1.25 .125 .005 On This Surface .195 .005 31.75 3.175 0.127 4.953 0.127 1.000 .005 .105 25.400 0.127 2.667 .32 .015 .003 3 Terminals Pins 8.13 0.127 0.076 Solderable .135 .50 .03 .028 .003 (1) (2) (3) 3.429 Dia. 2 Mounting Holes 12.70 0.76 0.711 0.076 .093 .005 I.D05 2.362 0.127 .30 1.27 7.62 .10 .70 .260 .015 2.54 17.78 6.604 0.381 Note: Model 78P dimensions applicable to all other models except as noted. Model 78L .062/1.575 Max. Meniscus 3 Electrical Leads 6/152 Min. Length No. 30 AWG Teflon Insulated Stranded Wire Yellow (1) Red (2) Green (3) .187 .031 Model 78S 4.750 0.787 3 Terminals Pins Solderable .028 .003 (1) (3) (2) Dia156 .031 .30 .02 0.711 0.075 Dia. 3.962 0.787 7.62 0.51 .05 .02 (3 Places) 1.27 0.51 .26 .02 .70 .02 .10 .02 6.60 0.51 17.78 0.51 2.54 0.51 Model 78 1-62