This 1965 circuit uses a Philips 4068 tube to measure extremely small charges. The circuit has as indicator a micro ammeter and the transistors are of the time.
August 2016 - It can be obtained from Mouser Electronics the new clock buffers HMC7043 of Analog...
This circuit appears elsewhere in this section, but taken from other sources. This is an English...
The integrated circuit used in this 80's temperature control is not very common today. The load...