This interesting digital counter with relays with complementary outputs was found in the Radio Electronics magazine of October 1961. The supply voltage is in accordance with the relays used.
Found in a 90s Popular Electronics, this circuit uses a simple 9 V source. The power can be used...
Originally the circuit in the figure is indicated by National for the control of an electronic car injection...
This simple receiver that works with only 1.5 V, was found in a 1987 documentation. The integrated...