Tell me the about IR sensors to be connected to HT12E & 12D for proper transmission

Tell me the about IR sensors to be connected to HT12E & 12D for proper transmission

hello sir,
actually i want to know about the simple IR l.e.d. & IR sensor's circuit diagrams as to connect it with HT12E & 12D.Is there any spcl connections we need here or simple one ? what values of differnt passive components we have to connect between IR L.e.d. & sensors ? Please show the actual circuit diagram relating this.

Re: Tell me the about IR sensors to be connected to HT12E & 12D for proper transmissi

In order to use a IR LED you need to change the encoder to the HT12A series, datasheet here:
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On the decoder side keep to use the HT12D.


Encoder diagram example here:

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see also the attached diagram.





Some components used for the transmitter :
1 IR LED, e.g.
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1 NPN bipolar transistor, e.g. BC337, PN2222, BD135, BD137

1 Ceramic filter 455KHz, e.g.
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The receiver section is very simple, circuit use one piece of infrared detector module ( IReceiver 38kHz ), e.g.

- TSOP4838
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- SFH 5110-38 IR receiver

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- TSOP31238




and one NPN bipolar small signal transistor, e.g. BC547, BC337...

Decoder diagram:
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Re: Tell me the about IR sensors to be connected to HT12E & 12D for proper transmissi

woww sir thanks a lot i can say the info is simply best . thanks thanks once again ! Is there any substitute for the 2N3904 or it has to be implant only & with what frequency the system u told will work in practice ? please reply sir

Re: Tell me the about IR sensors to be connected to HT12E & 12D for proper transmissi

You may replace 2N3904 with any NPN bipolar small signal transistor, e.g. BC547, BC337...

Re: Tell me the about IR sensors to be connected to HT12E & 12D for proper transmissi

Generally all the IR receivers already have open collector with internal pull-up for logic level out.

Your problem will be trying to locate stock on the parts as only the Chinese/Japanese consumer products use them now.

I used them over 10yrs ago and I see the ones I checked are not in stock. THe TV remote types are low data rate but work @20~60m. THe IRDA1 types can be made to work at 20m or more and the IRDA2 receivers are fastest bit rate but shortest distance. YOu can get the slow data rate ones at standard carrier freq like 36 38 40... etc but IRDA2 is fastest and does not you these low freq carriers. Easy to use except you must decouple the Vdd with an LC or RC filter to reduce noise levels to mV levels for maximum sensitivity.

Re: Tell me the about IR sensors to be connected to HT12E & 12D for proper transmissi

ok sir thanks a lot thank you very much i got it

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Sir is the 12E & 12A are practically same or the ic other than 12E with the name 12A is available comercially ?
can we use this 12E for IR trnsmissions ?

Re: Tell me the about IR sensors to be connected to HT12E & 12D for proper transmissi

rajaram04 said:

Sir is the 12E & 12A are practically same or the ic other than 12E with the name 12A is available comercially ?
can we use this 12E for IR trnsmissions ?

Click to expand...

The Holtek HT12E encoder was designed specifically for encoding RF transmissions, while the Holtek HT12A was designed specifically for the encoding IR transmissions.

For example, the Holtek HT12A provides the 38kHz carrier used in IR transmission, the Holtek HT12E does not.

By the way, the Holtek HT12A is End-of-Life (EOL), you may want to consider the Holtek HT62104 or HT622X series of IR encoders if you have trouble finding the HT12A second sourced.

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BigDog