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.
This small source is suitable for low consumption equipment that uses batteries. The circuit is...
This interesting circuit was found in an Argentinean Radio Chassis Television magazine from March...
This circuit is from an 80's documentation, firing when the input voltage exceeds 5 V. The SCR can...