kpratik
Newbie level 3
Hi everyone !! 
I was trying to construct an reliable contact less switch based on IR transmitter and receiver. The original Idea was brought up when I came across an circuit posted in Electronics for You. It was designed by an professor and was called "Touch Free Timer Switch".
Here is the circuits webpage link :
**broken link removed**
Now when I wanted to develop its design I found that TSOP 1738 is not available in local market reliably there I decided to go ahead with an similar Receiver that works on 38Khz frequency which is TSOP 4838. And speaking about the IC's I came across two Different makes one was LM555 by TI and NE555 by STM
Upon going through both the IC's datasheet I found that the combination of 1.2K, 1.3K and 10nF around the IC made it an perfect 38Khz Astable MVB. and combination of 100uF/25V electrolytic with 11K resistance made an 1 Sec Monostable MVB..
Coming to the problem :
When I arranged this ciruit everything is fine the circuit responds to all My hand gestures but after few hours it does not. :-?
Secondly when carefully observing the monostable confuguration in the datasheets it specifies that RESET and SUPPLY and connected by and Dotted Line :-?
Thridly Vreset for TI make IC is 1.67V and 2V for STM make if they have to be met for proper performance then how do i tune it with resistors ? :-?
Lastly- Is there any other way I can achieve contact less reliable switch ??
Hope Some One solves my problem
Thanks in Advance
Pratik :grin:
I was trying to construct an reliable contact less switch based on IR transmitter and receiver. The original Idea was brought up when I came across an circuit posted in Electronics for You. It was designed by an professor and was called "Touch Free Timer Switch".
Here is the circuits webpage link :
**broken link removed**
Now when I wanted to develop its design I found that TSOP 1738 is not available in local market reliably there I decided to go ahead with an similar Receiver that works on 38Khz frequency which is TSOP 4838. And speaking about the IC's I came across two Different makes one was LM555 by TI and NE555 by STM
Upon going through both the IC's datasheet I found that the combination of 1.2K, 1.3K and 10nF around the IC made it an perfect 38Khz Astable MVB. and combination of 100uF/25V electrolytic with 11K resistance made an 1 Sec Monostable MVB..
Coming to the problem :
When I arranged this ciruit everything is fine the circuit responds to all My hand gestures but after few hours it does not. :-?
Secondly when carefully observing the monostable confuguration in the datasheets it specifies that RESET and SUPPLY and connected by and Dotted Line :-?
Thridly Vreset for TI make IC is 1.67V and 2V for STM make if they have to be met for proper performance then how do i tune it with resistors ? :-?
Lastly- Is there any other way I can achieve contact less reliable switch ??
Hope Some One solves my problem
Thanks in Advance
Pratik :grin:
