Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

encoder/decoder Ir

Status
Not open for further replies.
1) The connections to your set and reset pins are still wrong. They need both a resistor and a capacitor to each of those pins. Look at the truth table in the datasheet to understand what arrangement the R and C should be in to preload the correct state at power up.

2) All input pins must be tied to something. Either +V or GND as is appropriate for the intended function. Inputs to CMOS logic devices must NOT be left floating.

3) The connections to the LED for the LCB717 are backwards.

And I agree with Pommie that your schematic is hard to read.
 
I see two inverters, but neither are configured as an oscillator.
Hi.
this is the photo my mobile phone takes, I can't do more.
I have some questions.
1) I used the simplest of oscillators, port 40106 resistor and capacitor.
what other oscillator can you use that has the maximum stability characteristic?
2) as an alternative to OPTOmos lcb717 is it possible to use the Analog Switches?. For example this? :
keep in mind that when the circuit is off its input is floating.
3) on flip flop A:
is it preferable to use the SET input or the J input?

1) I see two inverters, but neither are configured as an oscillator. What timing do you need? What stability do you need?
2) If it's just a power switch you could use a PNP transistor or a p-channel mosfet.
3) The CD4013 that you have listed for this part doesn't have a J input. If you're using it as an S-R latch, just use the SET pin. Why are you calling out different part numbers for the two flip-flops? The 74HC112 is a dual part. Just use both halves of that.
 
Last edited:
I see two inverters, but neither are configured as an oscillator.


1) I see two inverters, but neither are configured as an oscillator. What timing do you need? What stability do you need?
2) If it's just a power switch you could use a PNP transistor or a p-channel mosfet.

1) is not an oscillator but acts as an oscillator by resetting the flip flop. it has the function of transmitting high state - low state in sequence to the inputs of the ht12e encoder, reading the datasheet I cannot obtain the duration that this sequence must have.
2) must have the function of a normally closed switch with floating input.
 
Last edited:
I am exploring other alternatives and then choose the best one.
the question is about monostable multivibrators.
from what I see on the datasheets it seems that you can adjust the pulse duration through RC and up to here it's ok,
but is it possible to delay the appearance of the impulse after a certain time that I choose?
I have another question but this time it concerns the command inputs of the flip flops.
comparing the SR and JK-clock inputs which of the two commands takes precedence over the other.
let me explain: if a situation arises in which both inputs are activated which of the two takes over over the other?
 
Last edited:
I have another question but this time it concerns the command inputs of the flip flops.
comparing the SR and JK-clock inputs which of the two commands takes precedence over the other.
let me explain: if a situation arises in which both inputs are activated which of the two takes over over the other?

J-K flip flops toggle the output state if J and K are 1 and you get a proper clock pulse, I believe. The SR is indeterminate. These things rely on fast edges. You also have to set these things up to have the correct power-up state. Schmidt triggers can be used too create a fast edge from a slow edge signal.

Take a look at the TIMERBLOX series of parts by linear tecnology/analog devices.
 
J-K flip flops toggle the output state if J and K are 1 and you get a proper clock pulse, I believe. The SR is indeterminate. These things rely on fast edges. You also have to set these things up to have the correct power-up state. Schmidt triggers can be used too create a fast edge from a slow edge signal.

I apologize for phrasing the question incorrectly.
what i wanted to know is the following.
in my circuit the reset input of the flip flop remains activated for a certain time. what happens if at the same time I send a pulse to the "clock" if input J is connected to the high state?.

Take a look at the TIMERBLOX series of parts by linear tecnology/analog devices.

I have read the datasheet of LT6995.
if I understood right the DIV input must have a reference voltage that must not change and in my case I don't think it can work because I use a group of AA batteries and as they discharge the voltage changes. unless it uses a zener with much lower Vz placed at the head of the resistive divider.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top