This circuit is from a 1977 Signetics integrated circuit manual. The output transistors can be BD136 and BD237 and the symmetrical supply can be from 6 to 12 V. The voltage gain is 10.
This spinner (see CB18894E) uses only an operational amplifier that must be powered by a...
The incidence of light in the LDR causes this circuit to start operating, emitting a sound whose...
This circuit is from American documentation. The components used are still common. The power...