We found this circuit in an old Mullard (Philips) documentation on the 555 and 556 integrated circuit (double 555). The relay must be 12 V with contacts that support the horn current.
This simple 4-bit digital-to-analog converter was found in a 1974 publication. The transistors can be the...
Found in an Elektor from the 90s, this circuit is used with analog TV signals. The components are...
This small regulated power supply was found in a 1963 General Electric documentation. The special...