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encoder/decoder Ir

arivel

New Member
Hello . I'd like to ask you some questions please.
I have a problem with the Ir / Rf encoder / decoder ICs.
I only know the chip 145026/145027 no longer in production, then
holtek HT12E / HT12D, I don't know if others exist.
i would like to know if all encoders / decoders work like these two. Is there an online guide describing the existing encoders / decoders and types? .
I have to use the infrared mode, with a pulsate I have to transmit the high state - low state sequence to the other side. I don't know how long the high state and low state must last respectively on the D inputs and consequently the negative pulse on the TE input because I can't get it from the datasheet. I don't know what to use to control the encoder inputs, I don't want to use anything that is to be programmed.
what is usually used to control the encoders? is there a dedicated chip to control the encoder?
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Pretty well everything uses microcontrollers, both to encode and decode the IR/RF - the hardware chips were pretty naff anyway, and often greatly misused as people didn't understand what they were actually for (particularly the Holtek ones).

But if you want simple remote control chips, try the PT2262/2272
 

arivel

New Member
no thanks i don't want to use a microcontroller or anything else to program. I need something that controls the encoder inputs. to simplify the control circuit it would take an encoder, if any, which returns me a signal when it has finished transmitting. in this way maybe I can do without making a timed circuit. even better if it doesn't have the TE function but maybe that's too much to ask.
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Your actual requirements are pretty vague - so I've no idea exactly what you want - perhaps you might like to tell us?.

But the PT2262/2272 are similar to the HT12E/D in that they are for making a remote control, like you'd get on a TV.
 

arivel

New Member
I'm thinking about a circuit but I need some support. I have to bring the VCC power to the flip flop and at the same time, using the same track, activate the SET input of the flip flop. what can you use? I guess it takes a slight delay between power and input. I thought of a chain of buffers on the input.
 

ChrisP58

Well-Known Member
It sounds like you want the power up default state of the FF to be set (Q output high)

This can be easily done with a Resistor-Capacitor network connected to the set input pin. But the configuration depends on what FF you are using.

What's the part number of your flip-flop?
 

arivel

New Member
this simplified scheme is what I thought. everything is powered by stylus batteries.
an SCR in series with a normally closed OPTOmos (lcb717).
flip flop A is an SR, the other flip flop B clocked on the falling edge.
scr and optomos have the task of turning the circuit on and off, to use it only when needed. the reasons are two, to consume less energy and to obtain the repeat function when the button is pressed.
What do you think ?
 

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ChrisP58

Well-Known Member
this simplified scheme is what I thought. everything is powered by stylus batteries.
an SCR in series with a normally closed OPTOmos (lcb717).
flip flop A is an SR, the other flip flop B clocked on the falling edge.
scr and optomos have the task of turning the circuit on and off, to use it only when needed. the reasons are two, to consume less energy and to obtain the repeat function when the button is pressed.
What do you think ?
- What are "stylus batteries?"
- You have the capacitor that I mentioned on the S pin of flip flop A, but you need a resistor to ground on that pin to pull it low after power on. The C you've got on the R pin of flip flop B is wrong. What is it's purpose?
- What is the purpose of the SCR?
- What is the operating voltage of the circuit?
- What are the spec's of the encoder? Please post a link to it's datasheet.

When drawing a schematic, always put reference designators on all parts. It's a lot easier to comment if there are part numbers.
Also, clearly show the function of all pins on all components. The input and output of the LCB717 are not clear.
 

arivel

New Member
I answer the questions in the right order.
AA battery. two or three, I don't know yet.
.
the resistor on pin S of flip flop A (any SR flip flop) is present on the drawing maybe if you download the image on the PC you will see.
the capacitor on pin R of flip flop B (74HC112).
it has the function of supplying a negative impulse to obtain the reset.
the purpose of the SCR together with the OPTOMOS (LCB717)
there are two: operate the circuit only when needed to make the AA batteries last a long time.
achieve the repeat effect when pressing and holding the button contact.
the operating voltage depends on the voltage drop of the SCR and optomos, at least it is at least 1.2 volts, so I will probably have to use three AA batteries.
I have not yet chosen which IR encoder to use but the design was made based on HT12E.
which is what I know more than others.
tell me if it is still necessary to redo the drawing.
 

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