This is the circuit for the HM-10ª, an instrument sold by Heathkit. The circuit is from a Radio Electronics from May 1963. The indication is by an analog instrument.
This simple two transistor timer can be used to measure short time intervals. The power supply...
We found this circuit in documentation from the 90s. The circuit has a latch. The power supply must...
This circuit is from an Italian publication from 1988, but it can be assembled today because the...