This circuit with two 555s was found in the Encyclopedia of Electronic Circuits volume 5 of 1995. The power is high due to the use of 2N3055.
This General Electric circuit is from the 80's. The PUTs used in this meter are not common...
This circuit provides a power of the order of 2 W, characterized by high performance. The output...
The sensor can be made using two bare wire or two screen with a piece of tisse between them. One...