This simple injector circuit can actually be powered by voltages from 3 to 9 V. The frequency is given by C1 which can be between 4.7 and 10 nF. The CMOS can also be 4011.
This circuit was found in an EDN from the 90s. For the components indicated, the frequency is 10 kHz....
This circuit provides voltages and a 1 kHz signal for measurement bridges. The circuit is from...
We found this circuit in an old documentation, but it is still current. General purpose...