Electromechanical Timer Replacement - 320Volt

Time Delay Relay FamilyElectromechanical TimerReplacementAuthor:Paul McCoyZykoraWaukesha, WIUSAemail: paul_mccoy@zykora.comFIGURE 1:Input Signal+5VBLOCK DIAGRAMAPPLICATION OPERATIONThis design entry uses the PICmicro’s ability to beprogrammed in-circuit to create a large family ofdevices from one simple design. This will allow the costsavings of mass production while giving the salesleverage of customized components without longturn-around times or increased inventory requirements.Additionally, since the target market for this product isconsumer and industrial equipment manufacturers, theagency approvals (UL, CSA, European, etc.) should beeasier to get and maintain since there is only a fewhardware prototypes for the many incarnations.The devices that are being replaced either provide atime delay between the control signal coming on andthe relay activating, or provide a delay between the controlsignal going off and the relay deactivating. The timedelay is either a set value at manufacture or adjustablewithin a set range. This functionality is duplicated in thisdesign using the PIC12C671, a standard 5 VDC relay,and (in the case of an adjustable delay) a potentiometer.In fact this design makes it possible to have separatedelays for turn on and turn off.As mentioned previously, there are many implementationsof the software for one common hardware design.The source code included in this application note isbased on the dual adjustable model since the otherimplementations are a subset of this one. The range forthe adjustment is 0 – 31 seconds in this example.18GND27AN036AN145PIC12C671RelayGNDMICROCHIP TOOLS USEDAssembler/Compiler Version:MPLAB version 3.22.0 (MPASM)Rheostats foradjustabletime-delayoptionsMicrochip Technology Incorporated, has been granted a non-exclusive, worldwide license to reproduce, publish and distribute all submitted materials, ineither original or edited form. The author has affirmed that this work is an original, unpublished work and that he/she owns all rights to such work. Allproperty rights, such as patents, copyrights and trademarks remain with author.© 1997 Microchip Technology Inc. DS40160A/1_003-page 1