This circuit was found in an 80's EDN. The circuit uses a current common CMOS, the 4093 powering an LED. Trigger adjustment is done in a trimpot.
The frequency depends on the coil and is not found in the original documentation but should be...
This is a device for those who need to show that they know how to use digital electronics but have...
Using an operational amplifier with FET, this circuit from a 1977 publication can generate...