Insulated switch (CB21249E)

We found this circuit in a Popular Electronics from the 90s. The field effect transistor can be of any type.

| Clique na imagem para ampliar |

Limiter Preamplifier (CB20017E)
This circuit from an old documentation (1970s) combines the function of cutting or limiting the...
LED Polarity Indicator (CB17403E)
This circuit can be used to show the direction of current flow in semiconductors, such as LEDs....
Photoelectric alarm clock (CB16711E)
This circuit activates a relay when the sensor receives light indicating dawn. A relay with a 4k7...