Found in American documentation from the 1980s, this circuit has a diode feedback. At the exit we have an indicator LED. The LM3900 is a transconductance operational amplifier.
This circuit can be used with the CIR12053 receiver or with others shown in this section of the...
When the input of this circuit goes to high level, the LEDs start to flash alternately. The...
This circuit is from a 1965 Radio Electronics. The triggering transformer generates high voltage...