Series 38 Potentiometer 1/2 in. sq..5 Watt Series 39 Potentiometer 1/2 in. sq. 1. Watt Description The Series 38 and 39 are high-performance, low-cost potentiometers. They are also available with S.P.S.T. or S.P.D.T. rotary switch modules, S.P.S.T. momentary switch modules and/or potentiometer modules in multiple sections up to three sections. Features Compact - 1/2 in. (12.7mm) miniature, modular size. Cost-effective - Design simplicity through fewer component parts. Robust - Horizontal or vertical mountings with support plates. Nickel-plated brass shaft and bushings in various diameters and lengths. Insert molded gold plated terminals for strength. 38: Modular Style, Conductive Plastic 39: Modular Style, Thick-Film Cermet Series 38 is RoHS compliant. Precision Made - screen-printed conductive plastic and thick-film cermet elements. Stability - Series 38-4ºC to +12ºC; Series 39-4ºC to 15ºC operating temperature. Resistance Resistance Range End Resistance Power Rating Effective Rotation Dynamic Noise Series 38 Electrical Specifications 1Ω to 5 Megohms, linear; 5Ω to 2 Megohms, non-linear Linear: thru 5KΩ, ±1%; above 5K to 5 Megohms, ±2%. Non-linear thru 1KΩ, ±1%; above 1KΩ ±2% Linear: 4Ω maximum each end. Taper low side 4Ω maximum; high side 1% of total R..5 watt @ 7ºC. Derated linearly to zero watts at 12ºC. See Figure 2, page 3 For non-linear tapered units or PC mounting, derate by 5%. Trimmer style, derate by 5%. 265º ±5º without rotary switch; 24º ±5º with rotary switch. Standard: Linear single controls maximum initial noise level of 1.5% of total resistance. Measurement made using constant current source and oscilloscope detection technique. Special: 1% Series 39 Electrical Specifications Linear: 5Ω to 5 Megohms Taper: 1Ω to 2 Megohms ± 1% standard; ±5% special. Trimmers ±2%. 2Ω maximum, 5Ω to 25Ω; 4Ω maximum, 5KΩ and above. 1 watt @ 85ºC. Derate linearly to zero watts at 15ºC. For tapered units, trimmers or PC mounting, derate 5%. 25º +1º -5º without rotary switch; 225º +1º -5º with rotary switch. Standard: Linear single controls maximum initial noise level of 3% of total resistance. Measurement made using constant current source and oscilloscope detection technique. Special: 1.5% Electrical Specifications continued, next page Page 1
Electrical Specifications continued, next page Electrical Rotation Working Voltage Resistance Temperature Characteristics Linearity Non-linear Tapers Taper Tolerance Voltage Coefficient Dielectric Withstanding Voltage 295º ±5º 35 Vdc across end terminals, but power not to exceed rating. See Chart C. ±5% independent Right or left-hand available. See Chart A. ±2% of nominal resistance @ 5%; ±3% of mechanical rotation.8%/volt maximum. 75 Vac for 6 seconds @ ATM pressure. 35 Vac for 6 seconds @ 3.4 in. Hg. 295º ±5º 35 Vdc across end terminals, but power not to exceed rating. See Chart C. ±5% independent Right or left-hand available. See Chart A. ±2% of nominal resistance @ 5%; ±3% of mechanical rotation.8%/volt maximum 9 Vac for 6 seconds @ ATM pressure. 35 Vac for 6 seconds @ 3.4 in. Hg. Series 38/39 Mechanical Specifications Mechanical Rotation 295º ±5º Stop Torque 3 lb. in. minimum (metal shaft) Other torque options available. Please contact State Electronics. Torque Range.2 to 3. oz. in. (Single);.3 to 3.5 oz. in. (Dual);.4 to 4.5 oz. in. (Triple). Other torque options available. Please contact State Electronics. Torque Variation Within control.5 oz. in. maximum Bushing Material: Brass nickel plated Diameters: Supplied in.25" 32 NEF 2A thread (6.35mm) and.375" 32 NEF 2A thread (9.53mm) Lengths Available in.25" (6.35mm),.375"(9.53mm), and.5" (12.7mm). Styles: Plain, locking and trimmer Shafts Material: Brass nickel plated and stainless steel Diameters: Single shaft:.125" (3.18mm) and.25"(6.35mm) Concentric:.78"/.125" (1.98/3.18mm) and.125:/.25" (3.18/6.35mm) Lengths: Maximum of 3" (76.2mm) from bushing mounting surface;.25"(.635mm) minimum on trimmer or bushing Styles: Plain, slotted flatted and concentric Mechanical Specifications continued, next column Page 2 Push Momentary Switch S.P.S.T., 125ma, 28Vdc, push momentary switch. Type DJ Rotary Switch S.P.S.T. or S.P.D.T., CCW or CW, 125ma, 28Vdc. Type AL Housing Thermoplastic polyester, blue. (U.L. SE-O rating) Hardware Nut: brass, nickel-plated Lockwasher: phosphorous bronze, nickel-plated Solvent Resistance Housing resistant to trichlorethylene, *Chlorethene NU, Freon TMS, **Freon TMC, toluene, MEK, ethyl acetate and gasoline. For solvents not listed, please consult Factory. Note: Units not immersion sealed Terminals Gold-coated PC terminals or solder hook style. PC pins fit grid spacing. Terminal mounting options available Weight (approx.) Metal shaft & bushing: (Single).19 oz., (Dual).27 oz., (Triple).35 oz. * T.M. Dow Chemical Co. **T.M. Dupont
Series 38/39 Operational Specifications Operating Temperature Range Series 38: -4ºC to +12ºC Series 39: -4ºC to +15ºC Storage Temperature Range Series 38: -55ºC to +12ºC Series 39: -55ºC to +15ºC Rotational Life Series 38: linear control, 5, cycles under load, (plain bushing). Change not to exceed 1% R. Trimmer life under load is 5, cycles. Series 39: linear control, 25, cycles under load, (plain bushing). Change not to exceed 5% R. Trimmer life under load is 5, cycles. AL Switch Specifications Rating 125ma 28Vdc (dry circuit) Rotational Life 25, cycles under rated load BL and BLM Switch Specifications Rating 125ma 3Vdc (dry circuit) Rotational Life 15, cycles under rated load Figure 1 Chart A Figure 2 Chart B POWER DERATING GRAPH 1 9 1 8 REVERSE Z S 9 7 8 % RESISTANCE 6 5 4 3 2 Z RATED POWER IN PERCENT 7 6 5 4 1 3 1 2 3 4 5 6 7 8 9 1 Curves Standard % EFFECTIVE ROTATION CLOCKWISE The S taper is linear, the change in resistance value being directly proportional to the degree of rotation. It can be used either as righthand or left-hand taper. The Z taper attains 1% resistance value at 5% of clockwise rotation (left hand). 2 1 4 8 12 18 TEMPERATURE IN DEGREES CENTIGRADE The reverse Z taper attains 1% resistance value at 5% of counter-clockwise rotation (right-hand). For conformity and special output curves, contact State Electronics. Page 3
Figure 3 Chart C Nominal Maximum Percent Temporary Resistance Change From 25º Resistance -55ºC -4ºC ºC +25ºC +85ºC +15ºC +12ºC 1 Ohms 1K Ohms 1K Ohms 1 Megohm ±5. +7. +8. +1. ±4. +5.5 +6. +8. ±1.5 +2. +2.5 +3. ±1.5 ±1.5 ±2. ±2.5 ±2. ±2.5 ±3.5 ±4. ±3.5 ±5.5 ±6. ±7.5 Tolerance specifications apply to all layout drawings unless otherwise specified: fractions ±1/64 in. (.379mm); ±1/32 in. (.794mm) over 1 in. (25.4mm); decimals ±.5 in. (.127mm); PC board layout ±.1 in. (.254mm). For non-linear tapers, multiply chart values by 1.25 Figure 4 Series 38/39 Single, Dual or Triple (Second or Third Section May Be AL Series Rotary Switch) Printed Circuit Type B-22 C Terminal Length:.875 (22.3mm) Maximum Standard PC Terminal Length:.25 (6.36mm) 1.9 ±.15 [27.69 ±.38mm] MOUNTING SURFACE BUSHING LENGTH ±.16 [.41mm].79 ±.15 [2.7 ±.38mm].49 ±.15 [12.45 ±.38mm] SHAFT LENGTH ±.37 [.94mm ].31 [.79mm].31 [.79mm] +.1 [.25mm]. +.1 [.25mm]..5 ±.31 [12.7 ±.79mm].4 [1.2mm].8 ±.5 [2.3mm].16x45 [.4mm ] CHAMFER LOC. PIN NO. 1.5 ±.31 [12.7 ±.79mm].16 [.41mm].2 [5.6mm].125 ±.1 DIA. [3.17 ±.2mm ] 1/4 32 NEF 2A [6.35mm] THREAD SERIES 38-39.531 [13.49mm] "C" ±.15 [.38mm].25 [.63mm].25 [.63mm] LOC. PIN NO. 2 Figure 5 Series 38/39 Solder Lug Terminals Figure 6 Series 38/39 Bushingless Trimmer.53 ±.16 [13.89 ±.4mm].25 [.63mm].484 [12.3mm].2 [5.8mm].7 [1.78mm] HOOK WILL ACCEPT 3 NO. 22 AWG WIRES.55 [1.4mm].547 [13.89mm] MTG. SURFACE Page 4
Figure 7 Series 38/39 Single, Dual, or Triple with Panel and Rear Support Plates, Horizontal Mounting.25 [.63mm] MAX "A" ±.15 [.38mm] "C" ±.15 [.38mm].4 [1.2mm] P.C. BOARD MTG. SURFACE.15 [.38mm].125 ±.5 [3.17 ±.13 mm] [1.16mm] SERIES 38-39 P.C. TYPE B-24 SINGLE, DUAL OR TRIPLE PANEL AND REAR SUPPORT PLATES HORIZONTAL MOUNTING "A" "C" TYPE PLATE TERMINAL B24A-1.375 [ 9.52mm ].25 STD. [ 6.35mm] B24A-1.5 [ 12.7mm ].375 [ 9.52mm] B24A-1.625 [ 15.87mm ].5 [ 12.7mm] B24A-1.75 [ 19.5mm ].625 [ 15.87mm] B24A-1.255* [ 6.47mm ].125 [ 3.17mm] B24A-1 [ 7.62mm ].175 [ 4.44mm] B24A-1.437 [ 11.1mm ].315 [ 8.mm] B24A-1.562 [ 14.27mm ].425 [ 1.79mm] [1.16mm].2 [5.8mm].16 [4.6mm] [1.16mm].45 [11.43mm] * NOT USED AS MTG. SURFACE, PROVIDES STABILITY ONLY FOR P.C. BOARD MTG..7 [17.78mm] Figure 8 Series 38/39 Single or Dual.92 ±.15 [23.37 ±.38mm].6 ±.15 [15.24 ±.38mm].125 ±.1 DIA. [3.17 ±.2mm ].59 DIA. [1.5mm] TYP..35 DIA. [.89mm] TYP..23 [5.84mm].26 [6.6mm].79 [2.7mm] M.S..35 [.89mm].56 [14.22mm].49 [12.54mm].26 [6.6mm] 1/4 32 NEF 2A [6.35mm] THREAD [1.16mm].2 [5.8mm].25 [.63mm].2 [5.8mm] [1.16mm] SINGLE OR DUAL W/.25 [6.35mm] DIA. BUSHING.125 [3.12mm] DIA. SHAFT P/C OR SOLDER HOOK TERM. AVAILABLE OPTIONS AL ROTARY SWITCH VARIABLE LOCATING PINS Page 5
Figure 9 Series 38/39 Single or Dual.92 ±.15 [23.37 ±.38mm].6 ±.15 [15.24 ±.38mm].25 [6.35].59 DIA. [1.5mm] TYP..35 DIA. [.89mm] TYP..23 [5.84mm].26 [6.6mm].79 [2.7mm] M.S..35 [.89mm].56 [14.22mm].49 [12.54mm].26 [6.6mm].375 32 NEF 2A [9.52mm] THREAD [1.16mm].2 [5.8mm].25 [.63mm].2 [5.8mm] [1.16mm] SINGLE OR DUAL W/.375 [6.52mm] DIA. BUSHING.25 [6.35mm] DIA. SHAFT P/C OR SOLDER HOOK TERM. AVAILABLE OPTIONS AL ROTARY SWITCH VARIABLE LOCATING PINS Figure 1 Series 38/39 Single or Triple with High Rotational Torque 1.12 ±.15 [28.45 ±.38mm].8 ±.15 [2.32 ±.38mm].485 ±.15 [12.32 ±.38mm].25 [6.35].59 DIA. [1.5mm] TYP..35 DIA. [.89mm] TYP..23 [5.84mm].99 [25.15mm].76 [19.3mm].69 [17.53mm].46 [14.22mm] M.S..35 [.89mm].16 [4.6mm].39 [12.54mm].16 [6.6mm].375 32 NEF 2A [9.52mm] THREAD [1.16mm].2 [5.8mm].25 [.63mm].2 [5.8mm] [1.16mm] SINGLE OR DUAL W/.375 [6.52mm] DIA. BUSHING.25 [6.35mm] DIA. SHAFT P/C OR SOLDER HOOK TERM. AVAILABLE OPTIONS HIGH ROTATIONAL TORQUE VARIABLE LOCATING PINS Page 6
Figure 11 Series 38/39 Dual Concentric.125 ±.1 DIA. [3.17 ±.2mm].78 ±.1 DIA. [1.98 ±.2mm] Figure 12 Series 38/39 Type C-1A Printed Circuit Terminals.19 [2.77mm] DIA. ON 2 [1.16mm].5 [12.7mm].25 [6.35mm].35 DIA (ON 6) [.89mm] M.S..125 [3.17mm] Figure 13 Series 38/39 Type A-18A Printed Circuit Terminals.25 [6.35mm] or.375 [9.52mm].156 [3.99mm].35 DIA. (ON 3) [.89mm] Page 7
Figure 14 Series 38/39 Type C-8A Printed Circuit Terminals.19 [2.77mm] DIA. (ON 2).5 [12.7mm].25 [6.35mm].25 [.63mm] MAX..125 [3.17mm].35 DIA (ON 6) [.89mm] Figure 15 Series 38/39 Type C-9A Printed Circuit Terminals.5 [12.7mm].25 [6.35mm].35 DIA (ON 6) [.89mm].25 [.63mm] MAX..19 [2.77mm] DIA. (ON 2).125 [3.17mm] Series 38/39 Standard Resistance Values Stock Values (Ohms) 38N 1 1 1K 1K 1Meg 25 25 25K 25K 2.5Meg 5 5 5K 5K 5Meg 38N - PC 1 1 1K 1K 1Meg 25 25 25K 25K 2.5Meg 5 5 5K 5K 5Meg 38L 5 1K 1K 1 25K 25K 5 5K 5K 39N 1 1 1K 1K 1Meg 25 25 25K 25K 2.5Meg 5 5 5K 5K 5Meg 39L/D38/T38/D39/T39 Please contact State Electronics for price and delivery Series 38/39 How to Order Example: D38-N-PPS-1-Z D38 N PPS 1K Z Series 38 = Single Conductive Plastic - 1/2 watt D38 = Dual Conductive Plastic - 1/2 watt T38 = Triple Conductive Plastic - 1/2 watt 39 = Single Cermet - 1 watt D39 = Dual Cermet - 1 watt T39 = Triple Cermet - 1 watt Resistance Value (Ohms) Taper Z = Log RZ = Reverse Log S = Linear Switches S = Rotary switch S.P.D.T. PM = Push Momentary S.P.S.T. PPS = Push/pull switch S.P.D.T. No switch requirement = Blank Shaft & Bushing N = Shaft: 1/8 in (3.18mm) diameter x 3/4 in. (19.5mm) FMS screwdriver slotted Bushing: 1/4 in. (6.35mm) diameter x 1/4 in (6.35mm) length L = Shaft: 1/8 in (3.17mm) diameter x 7/16 in. (11.11mm) FMS screwdriver slotted Locking Bushing: 3/8 in. (9.52mm) x 1/4 in (6.35mm) 32-NEF 2A thread Page 8 Rev, 138