Thanks for the reply..I didn't check the calculations for frequency. Others have already commented on that. However, your planned transmitter will produce a steady signal of 4o kHz. The receiver will receive it, but because the signal is steady, its gain (AGC) will be turned down and sensitivity (i.e., range) will be low. If you want decent range, you need to pulse the 40 kHz "carrier" as shown in the datasheet for the TSOP1740:
View attachment 101549
That pulsing can be done without another 555 or both things can be done with a 556 chip. What range do you need?
Thanks i will try that.. i will let you know what happensHere is what I did many years ago. I don't have a nice schematic to show you, but here is what was simulated:
View attachment 101572
Here's the simulation:
View attachment 101573
I also did a version with the 556 chip, which is just two 555's inthe same package with fewer pins.
The way it works is the 555 on the right turns the 555 on the left on or off with the reset pin. The 555 on the left needs to be set at your 40 kHz. The one on the right at the repeat ("modulation") rate. There are other ways to do it too, such as using the trigger pin, but I liked this circuit better.
I actually never used that circuit as I moved to a PIC 12F509 microcontroller to do it; although, the circuit was built on a breadboard and worked. That was my first PIC project, and I never regretted making the change.
why are you using 56k Hz? Did you change your part number to TSOP1756? If not, then you loose 60% of sensitivity for each 10% error in frequency.I am trying to generate 56khz rather that 40khz, and i am using 100 for R3, that values for C, R1, R2.
0.1 µF 220 KΩ 18 KΩ
IR LED, this is the link for the actual IR LED i bought
- Part no.: 106526
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