Hello everyone

I made a IR transmitter and receiver using the schematic in this website

http://circuitdigest.com/electronic-circuits/ir-transmitter-and-receiver-circuit

but there is a problem regarding the receiver I use sliding switch instead of tact switch but when I switch on the transmitter for very long the led of the ir receiver will only stay for about 1 second how can i fix this?

 

I suspect this is a function of the TSOP. It expects a 38kHz modulated signal not a continuous 38kHz.
Try using another '555 running much slower with its output connected to the reset pin of the transmitter '555.

 

Do you mean I add a 555 timer in my receiver then connect the VO of the TSOP and reset pin of the 555

also instead of TSOP1738 I use HS0038

 

The extra '555 should be in the transmitter so the 38kHz is switched on and off repeatedly.
The following is from the HS0038 datasheet:
The data signal should fullfill the following condition:
• Carrier frequency should be close to center frequency of the bandpass (e.g. 38kHz)
• Burst length should be 10 cycles/burst or longer.
• After each burst which is between 10 cycles and 70 cycles a gap time of at least 14 cycles is neccessary.
• For each burst which is longer than 1.8ms a corresponding gap time is necessary at some time in the data stream. This gap time should be at least 4 times longer than the burst.
• Up to 800 short bursts per second can be received continuously.

 

I just noticed this in the datasheet. Note that the second item here is what you are attempting.

Some examples for such disturbance signals which are suppressed by the HS0038B are:
• DC light (e.g. from tungsten bulb or sunlight)
• Continuous signal at 38kHz or at any other frequency
• Signals from fluorescent lamps with electronic ballast with high or low modulation (see Figure A or Figure B).

 

the schematic in this website

so the BC557 is PNP - on their circuit set up with gain of 1 Ie=Ic+Ib , Ib=Ic e.g. doubling the base current for "emitter" that is now collector - and the "collector" current is approximately that of the base current . . .
if i look the tsop38 ds i assume OUT goes high cancelling the BC557 - besides the simple supply filter R1 C1 - shown on ds is omitted on CircuitDigest's v - i would email the author of this article and asked him - why it's good that way (theres alway smth. good for smth.)
... !Google ...
1738 this time

 

The extra '555 should be in the transmitter so the 38kHz is switched on and off repeatedly.
The following is from the HS0038 datasheet:
The data signal should fullfill the following condition:
• Carrier frequency should be close to center frequency of the bandpass (e.g. 38kHz)
• Burst length should be 10 cycles/burst or longer.
• After each burst which is between 10 cycles and 70 cycles a gap time of at least 14 cycles is neccessary.
• For each burst which is longer than 1.8ms a corresponding gap time is necessary at some time in the data stream. This gap time should be at least 4 times longer than the burst.
• Up to 800 short bursts per second can be received continuously.

Thank you can you please list the pins I should connect in the another 555 timer

so I also need to avoid other light disturbance for this?

 

so the BC557 is PNP - on their circuit set up with gain of 1 Ie=Ic+Ib , Ib=Ic e.g. doubling the base current for emitter
if i look the tsop38 ds i assume OUT goes high cancelling the BC557

The TSOP output is active low, so the receiver circuit should use a PNP transistor, but there is an error in the circuit diagram - the base and collector are swapped.

 

The second '555 should have the same components connected to it except that C1 should be 47nF. Pin 4 of the original '555 should be disconnected from the supply and connected to the Q output of the additional '555.

 

The second '555 should have the same components connected to it except that C1 should be 47nF. Pin 4 of the original '555 should be disconnected from the supply and connected to the Q output of the additional '555.

what do you mean by the pin 4 of the original '555 should be disconnected from the supply and connected to the Q output of the additional '555 what will happen to the switch and IR LED

 

so I also need to avoid other light disturbance for this?

No. The IR receiver will do that for you.

 

what do you mean by the pin 4 of the original '555 should be disconnected from the supply and connected to the Q output of the additional '555 what will happen to the switch and IR LED

The original '555 has pin 4 (reset) connected to the supply voltage. It should be disconnected from the supply and instead connected to pin 4 (output) of the new '555.

The switch and IR LED remain connected to pin 4 (the output) of the original '555.

 

The original '555 has pin 4 (reset) connected to the supply voltage. It should be disconnected from the supply and instead connected to pin 4 (output) of the new '555.

The switch and IR LED remain connected to pin 4 (the output) of the original '555.

thank you for this
also sorry but I made a mistake I thought you want me to disconnect the Q of the original 555 so I just need to disconnect the pin 4 original 555 from supply and connect it in the pin 4 of the new 555

 

I just need to disconnect the pin 4 original 555 from supply and connect it in the pin 4 of the new 555

Sorry, I mis-triped that. It should be:
I just need to disconnect the pin 4 original 555 from supply and connect it to pin 3 of the new 555

 

Sorry, I mis-triped that. It should be:
I just need to disconnect the pin 4 original 555 from supply and connect it to pin 3 of the new 555

Okay I will try this but can I ask if it is possible for example if I only tap the tact switch of transmitter the receiver will permanently go to ON MODE and if I tap it again it will permanently go to OFF MODE our professor told us that it is possible using IC 7486 and 7474 but he won't say it how so I want to ask if this is possible?

if so can you please elaborate on how will I do it because I need this kind of function because this time he want us to put the IR receiver to any electronics and the one I want to use is RADIO but it has a condition that will only function when you use 3V only.

 

74HC86 74HC74 NXP

 

I finally made it work what I just did is I made my ir receiver more simple I only used TSOP and an led with a resistor