There are three best and repeatedly proven schemes that differ only in key chips:
● scheme with ADG444
● circuit with КР590КН2 (differs from the first only in a printed circuit board);
● circuit from CD4066 (4016).
These schemes are 100% working, so no complaints about their inoperability are not accepted. If you have not earned something, then they themselves are to blame. Which one is better?
● КР590КН2 is difficult to find, besides, there are many defects among them (even cases where the sunlight falling on the chip caused self-excitation are described). If you get a KN-ka after the 91st year of release or in a brown case, do not take in any case – they are almost all defective.
● КР590КН2 has a complete analogue – ADG444, but these microcircuits are not very common, and also quite expensive.
● Devices assembled at КН5 are slightly more stable. But now it is almost impossible to get it.
Personally, my choice is a circuit with the use of a 4066 key chip (the third option). This microcircuit costs a penny, is sold everywhere, and at the same time it works without glitches.
Diagram with ADG444 (KR590KN5)
Diagram with KR590KN2 (KR590KN5)
This is the most budget and easily accessible version of the device.
In order for the 4066 chip to fully replace the KH5, additional piping in the form of several capacitors, resistors and 4 2N5551 transistors will be required.