This circuit retriggers when a new pulse arrives. It does this by discharging the capacitor. The circuit is from a documentation from the 80s. The transistor can be any general purpose one.
This circuit was found in many record players with crystal phono pickups. The output power is 800...
The 8038 is an integrated waveform generator (sinusoidal, triangular and rectangular) from...
This protector was found in an Electronics Now from the 90s. The 250 V transient suppressors are common...