Battery charger (CB9121E)

Found in an Electronics Now from the 1980s, this circuit uses some components that are still common today. For others, equivalents can be tested.

| Clique na imagem para ampliar |

200 mW FM transmitter (CB14878E)
This transmitter has a range of a few hundred meters depending on site conditions. The coil...
Multivibrator Lock Out Input LM139 (CB14239E)
The circuit shown below was obtained from the National Semiconductor Linear Applications Handbook...
Variable astable 4093 (CB21127E)
This circuit was found in a Popular Electronics from the 90s. The circuit has 4 frequency ranges...