1、Designation: F1661 09 (Reapproved 2015)Standard Test Method forDetermining the Contact Bounce Time of a MembraneSwitch1This standard is issued under the fixed designation F1661; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the contactbounce time of a membrane switch.1.2 The values stated
3、in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and he
4、alth practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2240 Test Method for Rubber PropertyDurometer Hard-nessF2592 Test Method for Measuring the Force-Displacementof a Membrane SwitchF1680 Test Method for Determining Circui
5、t Resistance of aMembrane Switch3. Terminology3.1 Definitions:3.1.1 contact bounceintermittent contact opening andcontact closure that may occur after switch operation.3.1.2 contact bounce time (break), TCBBthe time periodmeasured from the first instant VMis equal to the SUTV untilit constantly rema
6、ins below the SLTV after the last instant itrises above the SUTV. If VMdoes not rise above SUTV duringthe time interval, TCBB= 0, (see Fig. 1).3.1.3 contact bounce time (make), TCBMthe time periodmeasured from the first instant VMis equal to the SLTV untilit constantly remains above the SUTV after t
7、he last instant itfalls below the SLTV. If VMdoes not fall below SLTV duringthe time interval, TCBM= 0, (see Fig. 2).3.1.4 lower transition voltage, LTVthe voltage at whichthe switched logic device transitions to an “off” state.3.1.5 membrane switcha momentary switching device inwhich at least one c
8、ontact is on, or made of, a flexiblesubstrate.3.1.6 resistor, load, RLload resistance in series with switchunder test.3.1.7 specified lower transition voltage, SLTV minimumallowable LTV.3.1.8 specified upper transition voltage, SUTV minimumallowable UTV.3.1.9 upper transition voltage, UTVthe voltage
9、 at whichthe switched logic device transitions to an on” state.3.1.10 voltage, measured, VMvoltage measured acrossload Resistor (RL) by the oscilloscope and measured on itsscreen or voltage measured across the switch under test whena contact bounce measuring device is used.4. Significance and Use4.1
10、 Contact bounce time is essential to manufacturers andusers when designing interface circuitry because it specifies thetime delay necessary in the decoder circuitry to avoid any falsesignals caused by contact bounce. Allowing for time delaymakes the switch operation considerably more reliable.5. Int
11、erference5.1 The following parameters may affect the results of thistest:5.1.1 Mechanical probe materials (hardness) and speed willaffect results.6. Apparatus6.1 Test Probe, built to either of the configuration shown inFig. 3 and Fig. 4 are acceptable but must be made of an inertelastomeric material
12、 with a hardness number equivalent toA/45 6 5 as measured in accordance with Test Method D2240.Test probes that do not meet the above criteria must be fullyspecified and recorded.1This test method is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct responsibility of Subco
13、mmittee F01.18 on PrintedElectronics.Current edition approved June 1, 2015. Published August 2015. Originallyapproved in 1995. Last previous edition approved in 2009 as F1661 09. DOI:10.1520/F1661-09R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Ser
14、vice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16.2 Test Surface flat, smooth, unyielding, a
15、nd larger thanswitch under test.6.3 Oscilloscope, with recording capabilities and powersupply, or suitable contact bounce time measuring instrument.6.4 Device, which will consistently move probe into andaway from the switch at a controlled speed. Also capable ofapplying a specified force.7. Procedur
16、e7.1 Pretest Setup:7.1.1 Determine Fmax or Fc (whichever is greater) per TestMethod F2592.7.1.2 Determine switch resistance (RS) per Test MethodF1680.7.1.3 Secure switch on test surface.7.1.4 Connect switch terminals as shown in Fig. 5 so that:RL5 10 to 100 times RS7.1.5 Adjust oscilloscope to initi
17、al settings as follows:7.1.5.1 One half to 1.0 V/cm vertical, and7.1.5.2 Two to 3 ms/cm horizontal.7.1.5.3 Set SUTV per Fig. 6 if known. If not known, defaultSUTV will be 2.0 VDC.7.1.5.4 Set SLTV per Fig. 6 if known. If not known, defaultSLTV will be 0.9 VDC.7.1.6 Adjust power supply to test voltage
18、 per Fig. 6 ifknown. If not known, default test voltage will be 5 VDC.7.1.7 Adjust to rising waveform when measuring TCBM.7.1.8 Adjust to falling waveform when measuring TCBB.7.2 In Process Test (TCBM):7.2.1 Activate and release switch with test probe at thepredetermined force (7.1.6) at a cycling r
19、ate not to exceed 3cycles per second.7.2.2 Record TCBM(see Fig. 2) from oscilloscope display.7.2.3 Repeat 7.2.1 7.2.3 four more times.7.3 In Process Test (TCBB):7.3.1 Activate and release switch with test probe at thepredetermined force (7.1.6) at a cycling rate not to exceed 3cycles per second.7.3.
20、2 Record TCBB(see Fig. 1) from oscilloscope display.7.3.3 Repeat 7.3.1 7.3.3 four more times.FIG. 1 Contact Bounce on Switch BreakFIG. 2 Contact Bounce on Switch MakeFIG. 3 Test Probe OptionFIG. 4 Test Probe OptionFIG. 5 Test Setup OptionF1661 09 (2015)2FIG. 6 Table 1F1661 09 (2015)38. Report8.1 Rep
21、ort the following information:8.1.1 Temperature,8.1.2 Humidity,8.1.3 Barometric pressure,8.1.4 Specified resistance (RS),8.1.5 Load resistance (RL) (if using oscilloscope method),8.1.6 TCBM(min), TCBM(max),8.1.7 TCBB(min), TCBB(max),8.1.8 Part number or description of switch under test, orboth,8.1.9
22、 Date of test,8.1.10 Description of oscilloscope or contact bounce timemeasuring instrument,8.1.11 SUTV for oscilloscope method, UTV for contactbounce time measuring instrument method,8.1.12 SLTV for oscilloscope method, LTV for contactbounce time measuring instrument method,8.1.13 Completely descri
23、be means of activating switch,include details such as:8.1.13.1 Size, shape and durometer of probe,8.1.13.2 Actuation force,8.1.13.3 Velocity of probe, and8.1.13.4 Any other relevant information needed to duplicatetest.9. Precision and Bias9.1 PrecisionIt is not possible to specify the precision ofth
24、e procedure in Test Method F1661 for measuring contactbounce time because interlaboratory studies have proveninconclusive due to insufficient participating laboratories withthe appropriate equipment.9.2 BiasNo information can be presented on the bias ofthe procedure in Test Method F1661 for measurin
25、g contactbounce time because no standard sample is available for thisindustry.10. Keywords10.1 contact bounce; membrane switchASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are e
26、xpressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not rev
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28、ay attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United St
29、ates. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 09 (2015)4
