walid Posted October 3, 2006 Report Share Posted October 3, 2006 Hi from this link: http://home.maine.rr.com/randylinscott/aug98.htmIread the following:The MOD accepts a 40khz IR signal that is modulated at 4 khz. When a signal is received the MOD will go low. The sensitivity of the MOD is set by different values for R1 and C1. from that I understand that the modulating sig is 4khz and the modulated (carrier) sig is 40khzLook at the fig below: the freq of the transmitter sig is calculated from:f = 1/[0.693 x 0.05 uf x ( 2.2k + 2 x 1K)] =6.871kHz niether 40 nor 4 khzR1*C1 = 0.4 secfrom where he had that values of freq Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 3, 2006 Report Share Posted October 3, 2006 Hi Walid,Radio Shack doesn't have the specs for the MOD anymore so nobody knows what it does.Maybe it is just a photodetector that responds to any frequency of IR, then R1 and C1 filter its output. Quote Link to comment Share on other sites More sharing options...
walid Posted October 10, 2006 Author Report Share Posted October 10, 2006 Hi guruok, lets agree that Radio Shack doesn't have the specs for the MOD anymore so nobody knows what it does.i need you help in designing a gate guard using IR MOD as RX and IR diode as Txi baught the RX mod'si search the net but no circuit satisfied mei want your help guru so please help me Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 10, 2006 Report Share Posted October 10, 2006 Hi Walid,Replace the unknown MOD rx with a modern TSOP IR receiver module that is common in TVs. Look at its datasheet. Here is its sales sheet.Then tune the 555 to make 38kHz or 40kHz to match the new receiver. Quote Link to comment Share on other sites More sharing options...
walid Posted October 12, 2006 Author Report Share Posted October 12, 2006 Hi gurulook at the two figs below,If i use these circuits as Tx and Rx, and put my idenyified MOD....that is if i put and aligned these two circuit Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 12, 2006 Report Share Posted October 12, 2006 Hi Walid,We are just guessing about what is inside the MOD. Buy or steal a TSOP from a TV and get its datasheet then you will know what it is and how it works. Quote Link to comment Share on other sites More sharing options...
walid Posted October 13, 2006 Author Report Share Posted October 13, 2006 Try to forget this MODI have one and its datasheet, i know its pins and wait your answer to costruct the circuits abovei want to get logic 1 or 0 or any thing else at pin 3 of the nand gate when someone pass, is this possibe or not, or you have a better ideaplease tell methanks Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 13, 2006 Report Share Posted October 13, 2006 I don't know the spec's for your MOD so I don't know if it is sensitive to a certain frequency. You could make the circuit then experiment with different modulating frequencies to see if it is more sensitive to one. Quote Link to comment Share on other sites More sharing options...
walid Posted October 13, 2006 Author Report Share Posted October 13, 2006 Hi guru then experiment with different modulating frequencies to see if it is more sensitive to one. are u mean the Tx freq?OR u mean the Rx freq through R1 and C1, and if it respond to some freq what the output at pin 3 of the nand gatethank you very much Quote Link to comment Share on other sites More sharing options...
audioguru Posted October 13, 2006 Report Share Posted October 13, 2006 are u mean the Tx freq?Yes, the frequency of the 555 oscillator.OR u mean the Rx freq through R1 and C1, and if it respond to some freq what the output at pin 3 of the nand gateNo. R1 and C1 are just a lowpass filter so the output is DC and not the high frequency. Quote Link to comment Share on other sites More sharing options...
walid Posted October 13, 2006 Author Report Share Posted October 13, 2006 thank you guru very much you really helped me Quote Link to comment Share on other sites More sharing options...
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