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.
Here we show an oscillator that uses an LC network. The upper limit depends on the power-supply...
This regulated power supply can provide currents up to 1 A to a load. The transformer may actually have...
Obtained from a 1980s Linear Technology documentation, this circuit has a hysteresis of less than...