This circuit uses uncommon Texas Instruments components today. The circuit is from an American documentation. Transistors are commonly used PNP. The display is 7 segment multiplexed.
Based on FET operational amplifiers, this circuit was found in a manufactirer documentation. The...
This circuit, obtained from a 1965 magazine, can still be assembled using some modern equivalent...
This circuit uses an operational amplifier that is still common today. The indication is made by...