This circuit, based on a 555, was found in a Popular Electronics from the 90s. The circuit has the frequency determined by R1, R2 and C1.
We found this digital timer circuit in a 1994 publication. The power is supplied by 12 V, which is the...
We found this circuit in the 1982 SGS Linear Integrated Circuits manual. The transistor supports...
This simulated circuit on the NI Multisim transmits modulated infrared signals with the audio...