Hydrophone preamplifier (CB21486E)

This circuit was found in old American documentation. It has 40 dB gain between 10 Hz and 10 kHz. Modern equivalent transistors can be used.

| Clique na imagem para ampliar |

Fluorescent SCR Inverter (CB12328E)
This circuit is from a 1967 publication. It is possible to power a fluorescent lamp from a 12 V...
Modified Hartley Oscillator (CB21138E)
This circuit was found in old American documentation. Transistor is general purpose and coil rated...
Schmitt Trigger LM3900 (CB5049E)
With a strong positive feedback (via a 10 M resistor) we can get the trigger setting for the...