hi, I wanna replace the photo transistor of the below circuit with the common ir receiver (shown in figure 2)
so whats the new configuration ?
**broken link removed**
If figure 2 is the one in post #1, you can't do it.
The schematic shows a phototransistor that conducts when IR light falls on it so its collector voltage drops.
The black device is a photodiode, it is normally used to produce a tiny voltage when light falls on it or in a mode where it passes a tiny current.
You would need extra circuitry and a degree of experimentation to swap to the other device.