Heater for photo development (CB21390E)

Found in a 1965 General Electric documentation, this circuit is intended to control a 150 W lamp used as a heating element for developing photos.

| Clique na imagem para ampliar |

Field Strength Meter (CB18160E)
This circuit is from a 2004 documentation serving for signals from 1 MHz to 160 MHz. The antenna is...
Low Pass Filter with Transistors (CB19699E)
This filter of two transistors has the cutoff frequency determined by the formulas next to the...
24 W amplifier TDA1510 (CB19167E)
This Philips commercial circuit is from the 90's documentation. The integrated circuit must be...