Low battery indicator (CB9133E)

This circuit was found in Maxim's documentation from the 80's. The integrated circuit is from that time, uncommon today.

10 kHz oscillator (CB20349E)
This oscillator generates a fixed frequency signal determined by C1 and C2. In the case of 1 nF,...
Non-inverting amplifier LM741 (CB25919E)
This circuit has a gain of 10 for DC signals. The circuit is from a Radio Electronics from May...
Remote Control Receiver (CB18527E)
This circuit operates at 27 MHz serving as a receiver for the transmitter formed by CB18526 and...