When you look into regular famiclone zapper, you might encounter classic 1 transistor solution with values like:
or:
If you're more lucky, there might be 2 transistors:
But the Casel zapper (which uses additional chip HT2880 chip for riffle sound playback) has much more complicated photodiode sensing circuit:
Here is another revision:
Any idea how this circuit works?
--
![Image](https://obrazki.elektroda.pl/9220604800_1550778771_thumb.jpg)
![Image](https://obrazki.elektroda.pl/6936960800_1550778775_thumb.jpg)
![Image](https://obrazki.elektroda.pl/1239529300_1552657903_thumb.jpg)
or:
![Image](https://obrazki.elektroda.pl/3914894400_1550778857_thumb.jpg)
![Image](https://obrazki.elektroda.pl/1927716400_1550778862_thumb.jpg)
![Image](https://obrazki.elektroda.pl/4962703700_1552657924_thumb.jpg)
If you're more lucky, there might be 2 transistors:
![Image](https://obrazki.elektroda.pl/2590549500_1550778943_thumb.jpg)
![Image](https://obrazki.elektroda.pl/1564667800_1550778948_thumb.jpg)
![Image](https://obrazki.elektroda.pl/5340634500_1552657944_thumb.jpg)
But the Casel zapper (which uses additional chip HT2880 chip for riffle sound playback) has much more complicated photodiode sensing circuit:
![Image](https://obrazki.elektroda.pl/4928765100_1550779011_thumb.jpg)
![Image](https://obrazki.elektroda.pl/5094845200_1550779013_thumb.jpg)
![Image](https://obrazki.elektroda.pl/8130791500_1552658088_thumb.jpg)
Here is another revision:
![Image](https://obrazki.elektroda.pl/4592632800_1550779071_thumb.jpg)
![Image](https://obrazki.elektroda.pl/6004076300_1550779075_thumb.jpg)
![Image](https://obrazki.elektroda.pl/2067710200_1550779076_thumb.jpg)
Any idea how this circuit works?
--